Re: [R] print and lapply....
Dear Rui,
THanks a lot!
THanking you,
Yours sincerely
AKSHAY M KULKARNI
From: Rui Barradas
Sent: Tuesday, November 8, 2022 8:51 PM
To: akshay kulkarni ; R help Mailing list
Subject: Re: [R] print and lapply
�s 14:47 de 08/11/2022, akshay kulkarni escreveu:
> Dear Rui,
>The replies from you, Bert, Tim and solved my problem. My
> last question: what if I put print inside the body of the function passed on
> to lapply, instead of separately in the function argument of apply? Is this
> what you insinuated in your reply?
>
> THanking you,
> yours sincerely,
> AKSHAY M KULKARNI
>
> From: Rui Barradas
> Sent: Tuesday, November 8, 2022 2:20 AM
> To: akshay kulkarni ; R help Mailing list
>
> Subject: Re: [R] print and lapply
>
> �s 19:22 de 07/11/2022, akshay kulkarni escreveu:
>> Dear Rui,
>>THanks for your reply...The point is the loop is a
>> scraping code, and in your examples you have assumed that the body acts on
>> i, the loop variable. Can you adapt your code to JUST PRINT the loop
>> variable i ?
>>
>> By the by, I think I have stumbled upon the answer: The lapply() caches the
>> result, and prints the output of the function in question immediately after
>> printing the final i. The i's get printed serially, as the function
>> progresses
>>
>>> lapply(1:4,function(x){print(x);Sys.sleep(x^2);x^2})
>> [1] 1
>> [1] 2
>> [1] 3
>> [1] 4
>> [[1]]
>> [1] 1
>>
>> [[2]]
>> [1] 4
>>
>> [[3]]
>> [1] 9
>>
>> [[4]]
>> [1] 16
>>
>> Here x^2 's print only after 4 is printed on the console
>>
>> tHanks anyways for your reply
>>
>> THanking you,
>> Yours sincerely,
>> AKSHAY M KULKARNI
>>
>> From: Rui Barradas
>> Sent: Tuesday, November 8, 2022 12:24 AM
>> To: akshay kulkarni ; R help Mailing list
>>
>> Subject: Re: [R] print and lapply
>>
>> �s 18:33 de 07/11/2022, akshay kulkarni escreveu:
>>> Dear Rui,
>>> Actually, I am replacing a big for loop by the
>>> lapply() function, and report the progress:
>>>
>>> lapply(TP, function(i) { BODY; print(i)})
>>>
>>> Can you please adjust your solution in this light?
>>>
>>> THanking you,
>>> Yours sincerely,
>>> AKSHAY M KULKARNI
>>>
>>> From: Rui Barradas
>>> Sent: Monday, November 7, 2022 11:59 PM
>>> To: akshay kulkarni ; R help Mailing list
>>>
>>> Subject: Re: [R] print and lapply
>>>
>>> �s 17:17 de 07/11/2022, akshay kulkarni escreveu:
>>>> Dear members,
>>>> I have the following code and output:
>>>>
>>>>> TP <- 1:4
>>>>> lapply(TP,function(x){print(x);x^2})
>>>> [1] 1
>>>> [1] 2
>>>> [1] 3
>>>> [1] 4
>>>> [[1]]
>>>> [1] 1
>>>>
>>>> [[2]]
>>>> [1] 4
>>>>
>>>> [[3]]
>>>> [1] 9
>>>>
>>>> [[4]]
>>>> [1] 16
>>>>
>>>> How do I make the print function output x along with x^2, i.e not at the
>>>> beginning but before each of x^2?
>>>>
>>>> Many thanks in advance
>>>>
>>>> THanking you,
>>>> Yours sincerely
>>>> AKSHAY M KULKARNI
>>>>
>>>> [[alternative HTML version deleted]]
>>>>
>>>> __
>>>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
>>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>>> PLEASE do read the posting guide
>>>> http://www.R-project.org/posting-guide.html
>>>> and provide commented, minimal, self-contained, reproducible code.
>>> Hello,
>>>
>>> Here are two options, with ?cat and with ?message.
>>>
>>>
>>> TP <- 1:4
>>> lapply(TP, function(x){
>>> cat("x =", x, "x^2 =", x^2, "\n")
>>> })
>>>
>>> lapply(TP, function(x){
>>> msg <- paste("x =", x, "x^2 =", x^2)
>>> message(msg)
>>> })
>>>
>>>
>>> Hope this helps,
>>>
>>>
Re: [R] print and lapply....
Às 14:47 de 08/11/2022, akshay kulkarni escreveu:
Dear Rui,
The replies from you, Bert, Tim and solved my problem. My
last question: what if I put print inside the body of the function passed on to
lapply, instead of separately in the function argument of apply? Is this what
you insinuated in your reply?
THanking you,
yours sincerely,
AKSHAY M KULKARNI
From: Rui Barradas
Sent: Tuesday, November 8, 2022 2:20 AM
To: akshay kulkarni ; R help Mailing list
Subject: Re: [R] print and lapply
Às 19:22 de 07/11/2022, akshay kulkarni escreveu:
Dear Rui,
THanks for your reply...The point is the loop is a scraping
code, and in your examples you have assumed that the body acts on i, the loop
variable. Can you adapt your code to JUST PRINT the loop variable i ?
By the by, I think I have stumbled upon the answer: The lapply() caches the
result, and prints the output of the function in question immediately after
printing the final i. The i's get printed serially, as the function
progresses
lapply(1:4,function(x){print(x);Sys.sleep(x^2);x^2})
[1] 1
[1] 2
[1] 3
[1] 4
[[1]]
[1] 1
[[2]]
[1] 4
[[3]]
[1] 9
[[4]]
[1] 16
Here x^2 's print only after 4 is printed on the console
tHanks anyways for your reply
THanking you,
Yours sincerely,
AKSHAY M KULKARNI
From: Rui Barradas
Sent: Tuesday, November 8, 2022 12:24 AM
To: akshay kulkarni ; R help Mailing list
Subject: Re: [R] print and lapply
Às 18:33 de 07/11/2022, akshay kulkarni escreveu:
Dear Rui,
Actually, I am replacing a big for loop by the lapply()
function, and report the progress:
lapply(TP, function(i) { BODY; print(i)})
Can you please adjust your solution in this light?
THanking you,
Yours sincerely,
AKSHAY M KULKARNI
From: Rui Barradas
Sent: Monday, November 7, 2022 11:59 PM
To: akshay kulkarni ; R help Mailing list
Subject: Re: [R] print and lapply
Às 17:17 de 07/11/2022, akshay kulkarni escreveu:
Dear members,
I have the following code and output:
TP <- 1:4
lapply(TP,function(x){print(x);x^2})
[1] 1
[1] 2
[1] 3
[1] 4
[[1]]
[1] 1
[[2]]
[1] 4
[[3]]
[1] 9
[[4]]
[1] 16
How do I make the print function output x along with x^2, i.e not at the
beginning but before each of x^2?
Many thanks in advance
THanking you,
Yours sincerely
AKSHAY M KULKARNI
[[alternative HTML version deleted]]
__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Hello,
Here are two options, with ?cat and with ?message.
TP <- 1:4
lapply(TP, function(x){
cat("x =", x, "x^2 =", x^2, "\n")
})
lapply(TP, function(x){
msg <- paste("x =", x, "x^2 =", x^2)
message(msg)
})
Hope this helps,
Rui Barradas
Hello,
What do you want the lapply loop to return? If you have a BODY doing
computations, do you want the lapply to return those values and report
the progress?
I have chosen cat or message over print because
- cat returns invisible(NULL),
- message returns invisible()
- print returns a value, what it prints.
Can you adapt the code below to your use case?
TP <- 1:4
lapply(TP, function(x, verbose = TRUE){
# BODY
y <- rnorm(100, mean = x)
# show progress
if(verbose)
cat("x =", x, "x^2 =", x^2, "\n")
#return value
c(x = x, mean = mean(y))
})
lapply(TP, function(x, verbose = TRUE){
# BODY
y <- rnorm(100, mean = x)
# show progress
if(verbose) {
msg <- paste("x =", x, "x^2 =", x^2)
message(msg)
}
#return value
c(x = x, mean = mean(y))
})
Hope this helps,
Rui Barradas
Hello,
No, the x^2 are not printed after the i's. The x^2 are the function's
return values. The function prints the i's, then returns x^2.
As for your problem, it is now more clerar.
I would write a function accepting a url to take care of scraping and
call it in the lapply loop. The progress report can be in the loop, like
below.
This is a complete working example, scraping the Wikipedia list of
countries by GDP. The urls are in a list (it's always the same, I'm not
complicating things) and in a real scraping function I would wrap
tryCatch around it, just in case.
First the function, then the urls list, then the lapply loop.
library(rvest)
scrape <- function(url) {
page <- read_html(url)
gdp <- page |>
html_element(".wikitable") |>
html_table() |>
as.data.frame()
names(gdp) <- unlist(gdp[1,, drop = TRUE
Re: [R] print and lapply....
Dear Tim,
I think the recent replies from you, Bert and Rui cleared
everything ...
THanks a lot..
Thanking you,
Yours sincerely,
AKSHAY M KULKARNI
From: Ebert,Timothy Aaron
Sent: Tuesday, November 8, 2022 2:15 AM
To: akshay kulkarni ; Bert Gunter
; Andrew Simmons
Cc: R help Mailing list
Subject: RE: [R] print and lapply
Dear Akshay,
I think we have provided several solutions to the question asked. Can you
please adjust your question to more closely align with what you need. It would
be nice if you can provide sufficient detail so that we can see how you have
adapted our solutions and how these have not quite addressed this problem.
Tim
-Original Message-
From: R-help On Behalf Of akshay kulkarni
Sent: Monday, November 7, 2022 1:10 PM
To: Bert Gunter ; Andrew Simmons
Cc: R help Mailing list
Subject: Re: [R] print and lapply
[External Email]
Dear Bert,
Actually, I am replacing a big for loop by the lapply()
function, and report the progress:
lapply(TP, function(i) { BODY; print(i)})
Can you please adjust your solution in this light?
THanking you,
Yours sincerely,
AKSHAY M KULKARNI
From: Bert Gunter
Sent: Monday, November 7, 2022 11:16 PM
To: Andrew Simmons
Cc: akshay kulkarni ; R help Mailing list
Subject: Re: [R] print and lapply
Well... yes, of course. But assuming the sole purpose is to print the results
and not to save them for further processing, the OP's approach seems rather
painful. My preference would be to vectorize:
> print(cbind(TP, TPsq =TP^2), print.gap = 3)
TP TPsq
[1,]1 1
[2,]2 4
[3,]3 9
[4,]4 16
See ?print.default for details
-- Bert
On Mon, Nov 7, 2022 at 9:20 AM Andrew Simmons wrote:
>
> put print() around x^2
>
> On Mon, Nov 7, 2022, 12:18 akshay kulkarni wrote:
>
> > Dear members,
> > I have the following code and output:
> >
> > > TP <- 1:4
> > > lapply(TP,function(x){print(x);x^2})
> > [1] 1
> > [1] 2
> > [1] 3
> > [1] 4
> > [[1]]
> > [1] 1
> >
> > [[2]]
> > [1] 4
> >
> > [[3]]
> > [1] 9
> >
> > [[4]]
> > [1] 16
> >
> > How do I make the print function output x along with x^2, i.e not at
> > the beginning but before each of x^2?
> >
> > Many thanks in advance
> >
> > THanking you,
> > Yours sincerely
> > AKSHAY M KULKARNI
> >
> > [[alternative HTML version deleted]]
> >
> > __
> > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fst
> > at.ethz.ch%2Fmailman%2Flistinfo%2Fr-helpdata=05%7C01%7Ctebert%4
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> > 62331e1b84%7C0%7C0%7C638034414365456384%7CUnknown%7CTWFpbGZsb3d8eyJW
> > IjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C300
> > 0%7C%7C%7Csdata=dQk1JPxWI4D0D6%2FSoC8LWw56749ulaFrGQc6affgBeM%3
> > Dreserved=0
> > PLEASE do read the posting guide
> > https://nam10.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww
> > .r-project.org%2Fposting-guide.htmldata=05%7C01%7Ctebert%40ufl.
> > edu%7Cb726a89349ed4860265708dac0eb5d0a%7C0d4da0f84a314d76ace60a62331
> > e1b84%7C0%7C0%7C638034414365456384%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiM
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> > 7C%7Csdata=KDskHBxmxe0DV9XO7GvkESemUNTq2w%2BT%2Fro%2Bgb4DS2w%3D
> > reserved=0 and provide commented, minimal, self-contained,
> > reproducible code.
> >
>
> [[alternative HTML version deleted]]
>
> __
> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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> .ethz.ch%2Fmailman%2Flistinfo%2Fr-helpdata=05%7C01%7Ctebert%40ufl
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> 1b84%7C0%7C0%7C638034414365456384%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4w
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> sdata=OxZmpA4ORbfUq0gq
Re: [R] print and lapply....
Dear Rui,
The replies from you, Bert, Tim and solved my problem. My
last question: what if I put print inside the body of the function passed on to
lapply, instead of separately in the function argument of apply? Is this what
you insinuated in your reply?
THanking you,
yours sincerely,
AKSHAY M KULKARNI
From: Rui Barradas
Sent: Tuesday, November 8, 2022 2:20 AM
To: akshay kulkarni ; R help Mailing list
Subject: Re: [R] print and lapply
�s 19:22 de 07/11/2022, akshay kulkarni escreveu:
> Dear Rui,
> THanks for your reply...The point is the loop is a scraping
> code, and in your examples you have assumed that the body acts on i, the loop
> variable. Can you adapt your code to JUST PRINT the loop variable i ?
>
> By the by, I think I have stumbled upon the answer: The lapply() caches the
> result, and prints the output of the function in question immediately after
> printing the final i. The i's get printed serially, as the function
> progresses
>
>> lapply(1:4,function(x){print(x);Sys.sleep(x^2);x^2})
> [1] 1
> [1] 2
> [1] 3
> [1] 4
> [[1]]
> [1] 1
>
> [[2]]
> [1] 4
>
> [[3]]
> [1] 9
>
> [[4]]
> [1] 16
>
> Here x^2 's print only after 4 is printed on the console
>
> tHanks anyways for your reply
>
> THanking you,
> Yours sincerely,
> AKSHAY M KULKARNI
>
> From: Rui Barradas
> Sent: Tuesday, November 8, 2022 12:24 AM
> To: akshay kulkarni ; R help Mailing list
>
> Subject: Re: [R] print and lapply
>
> �s 18:33 de 07/11/2022, akshay kulkarni escreveu:
>> Dear Rui,
>> Actually, I am replacing a big for loop by the lapply()
>> function, and report the progress:
>>
>> lapply(TP, function(i) { BODY; print(i)})
>>
>> Can you please adjust your solution in this light?
>>
>> THanking you,
>> Yours sincerely,
>> AKSHAY M KULKARNI
>>
>> From: Rui Barradas
>> Sent: Monday, November 7, 2022 11:59 PM
>> To: akshay kulkarni ; R help Mailing list
>>
>> Subject: Re: [R] print and lapply
>>
>> �s 17:17 de 07/11/2022, akshay kulkarni escreveu:
>>> Dear members,
>>> I have the following code and output:
>>>
>>>> TP <- 1:4
>>>> lapply(TP,function(x){print(x);x^2})
>>> [1] 1
>>> [1] 2
>>> [1] 3
>>> [1] 4
>>> [[1]]
>>> [1] 1
>>>
>>> [[2]]
>>> [1] 4
>>>
>>> [[3]]
>>> [1] 9
>>>
>>> [[4]]
>>> [1] 16
>>>
>>> How do I make the print function output x along with x^2, i.e not at the
>>> beginning but before each of x^2?
>>>
>>> Many thanks in advance
>>>
>>> THanking you,
>>> Yours sincerely
>>> AKSHAY M KULKARNI
>>>
>>> [[alternative HTML version deleted]]
>>>
>>> __
>>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>>> and provide commented, minimal, self-contained, reproducible code.
>> Hello,
>>
>> Here are two options, with ?cat and with ?message.
>>
>>
>> TP <- 1:4
>> lapply(TP, function(x){
>> cat("x =", x, "x^2 =", x^2, "\n")
>> })
>>
>> lapply(TP, function(x){
>> msg <- paste("x =", x, "x^2 =", x^2)
>> message(msg)
>> })
>>
>>
>> Hope this helps,
>>
>> Rui Barradas
>>
>>
>>
> Hello,
>
>
> What do you want the lapply loop to return? If you have a BODY doing
> computations, do you want the lapply to return those values and report
> the progress?
>
> I have chosen cat or message over print because
>
>- cat returns invisible(NULL),
>- message returns invisible()
>- print returns a value, what it prints.
>
> Can you adapt the code below to your use case?
>
>
>
> TP <- 1:4
> lapply(TP, function(x, verbose = TRUE){
> # BODY
> y <- rnorm(100, mean = x)
>
> # show progress
> if(verbose)
> cat("x =", x, "x^2 =", x^2, "\n")
>
> #return value
> c(x = x, mean = mean(y))
> })
>
> lapply(TP, function(x, verbose = TRUE){
> # BODY
> y <- rnorm(100,
Re: [R] print and lapply....
Dear Bert,
Amazing! Very informative...THanks a lot.
From: Bert Gunter
Sent: Tuesday, November 8, 2022 2:15 AM
To: akshay kulkarni
Cc: Rui Barradas ; R help Mailing list
Subject: Re: [R] print and lapply
" The lapply() caches the result, and prints the output of the
function in question immediately after printing the final i. "
I don't believe you understand how lists or lapply works. You seem to
be trying to intuit from empirical behavior. Bad idea, if so. You need
to read the docs or spend time with suitable tutorials.
Consider:
lapply produces a **list,** each component of which is the result of
applying a function, FUN, to the components of its first argument
(here 1:4), which is itself a list. Results are **not** cached in the
sense you seem to think they are. The list object that is produced by
the function is **only** printed if you ask it to be (via cat, print,
or whatever) or, by default, if the result is unassigned. The default
printing can be turned off via the invisible() function.
So:
> res <- lapply(TP, function(x){
+print(x)
+x^2}
+)
[1] 1
[1] 2
[1] 3
[1] 4
[1] 5
## Nothing printed, but the results are the components of **list**
res, which can be printed on the console by print(res) or simply:
> res ## note the list syntax below
[[1]]
[1] 1
[[2]]
[1] 4
[[3]]
[1] 9
[[4]]
[1] 16
[[5]]
[1] 25
Now can you explain what happens here:
> invisible(lapply(TP, function(x){
+print(x)
+x^2}
+))
[1] 1
[1] 2
[1] 3
[1] 4
[1] 5
> ## results not printed; nothing assigned. Where can you find them? (See below)
or here:
> lapply(TP, function(x){
+print(x)
+x^2}
+)
[1] 1
[1] 2
[1] 3
[1] 4
[1] 5
[[1]]
[1] 1
[[2]]
[1] 4
[[3]]
[1] 9
[[4]]
[1] 16
[[5]]
[1] 25
## How could you recover the results of the lapply and not just look
at the console printout if the results have not been assigned?
## Hint: See ?.Last.value
-- Bert
On Mon, Nov 7, 2022 at 11:22 AM akshay kulkarni wrote:
>
> Dear Rui,
> THanks for your reply...The point is the loop is a scraping
> code, and in your examples you have assumed that the body acts on i, the loop
> variable. Can you adapt your code to JUST PRINT the loop variable i ?
>
> By the by, I think I have stumbled upon the answer: The lapply() caches the
> result, and prints the output of the function in question immediately after
> printing the final i. The i's get printed serially, as the function
> progresses
>
> > lapply(1:4,function(x){print(x);Sys.sleep(x^2);x^2})
> [1] 1
> [1] 2
> [1] 3
> [1] 4
> [[1]]
> [1] 1
>
> [[2]]
> [1] 4
>
> [[3]]
> [1] 9
>
> [[4]]
> [1] 16
>
> Here x^2 's print only after 4 is printed on the console
>
> tHanks anyways for your reply
>
> THanking you,
> Yours sincerely,
> AKSHAY M KULKARNI
> ____________
> From: Rui Barradas
> Sent: Tuesday, November 8, 2022 12:24 AM
> To: akshay kulkarni ; R help Mailing list
>
> Subject: Re: [R] print and lapply
>
> �s 18:33 de 07/11/2022, akshay kulkarni escreveu:
> > Dear Rui,
> > Actually, I am replacing a big for loop by the lapply()
> > function, and report the progress:
> >
> > lapply(TP, function(i) { BODY; print(i)})
> >
> > Can you please adjust your solution in this light?
> >
> > THanking you,
> > Yours sincerely,
> > AKSHAY M KULKARNI
> >
> > From: Rui Barradas
> > Sent: Monday, November 7, 2022 11:59 PM
> > To: akshay kulkarni ; R help Mailing list
> >
> > Subject: Re: [R] print and lapply
> >
> > �s 17:17 de 07/11/2022, akshay kulkarni escreveu:
> >> Dear members,
> >>I have the following code and output:
> >>
> >>> TP <- 1:4
> >>> lapply(TP,function(x){print(x);x^2})
> >> [1] 1
> >> [1] 2
> >> [1] 3
> >> [1] 4
> >> [[1]]
> >> [1] 1
> >>
> >> [[2]]
> >> [1] 4
> >>
> >> [[3]]
> >> [1] 9
> >>
> >> [[4]]
> >> [1] 16
> >>
> >> How do I make the print function output x along with x^2, i.e not at the
> >> beginning but before each of x^2?
> >>
> >> Many thanks in advance
> >>
> >> THanking you,
> >> Yours sincerely
> >> AKSHAY M KULKARNI
> >>
> >> [[alternative HTML version deleted]]
> >>
> >> __
> >> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> >> https://stat.ethz.ch/mailm
Re: [R] print and lapply....
Às 19:22 de 07/11/2022, akshay kulkarni escreveu:
Dear Rui,
THanks for your reply...The point is the loop is a scraping
code, and in your examples you have assumed that the body acts on i, the loop
variable. Can you adapt your code to JUST PRINT the loop variable i ?
By the by, I think I have stumbled upon the answer: The lapply() caches the
result, and prints the output of the function in question immediately after
printing the final i. The i's get printed serially, as the function
progresses
lapply(1:4,function(x){print(x);Sys.sleep(x^2);x^2})
[1] 1
[1] 2
[1] 3
[1] 4
[[1]]
[1] 1
[[2]]
[1] 4
[[3]]
[1] 9
[[4]]
[1] 16
Here x^2 's print only after 4 is printed on the console
tHanks anyways for your reply
THanking you,
Yours sincerely,
AKSHAY M KULKARNI
From: Rui Barradas
Sent: Tuesday, November 8, 2022 12:24 AM
To: akshay kulkarni ; R help Mailing list
Subject: Re: [R] print and lapply
Às 18:33 de 07/11/2022, akshay kulkarni escreveu:
Dear Rui,
Actually, I am replacing a big for loop by the lapply()
function, and report the progress:
lapply(TP, function(i) { BODY; print(i)})
Can you please adjust your solution in this light?
THanking you,
Yours sincerely,
AKSHAY M KULKARNI
From: Rui Barradas
Sent: Monday, November 7, 2022 11:59 PM
To: akshay kulkarni ; R help Mailing list
Subject: Re: [R] print and lapply
Às 17:17 de 07/11/2022, akshay kulkarni escreveu:
Dear members,
I have the following code and output:
TP <- 1:4
lapply(TP,function(x){print(x);x^2})
[1] 1
[1] 2
[1] 3
[1] 4
[[1]]
[1] 1
[[2]]
[1] 4
[[3]]
[1] 9
[[4]]
[1] 16
How do I make the print function output x along with x^2, i.e not at the
beginning but before each of x^2?
Many thanks in advance
THanking you,
Yours sincerely
AKSHAY M KULKARNI
[[alternative HTML version deleted]]
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Hello,
Here are two options, with ?cat and with ?message.
TP <- 1:4
lapply(TP, function(x){
cat("x =", x, "x^2 =", x^2, "\n")
})
lapply(TP, function(x){
msg <- paste("x =", x, "x^2 =", x^2)
message(msg)
})
Hope this helps,
Rui Barradas
Hello,
What do you want the lapply loop to return? If you have a BODY doing
computations, do you want the lapply to return those values and report
the progress?
I have chosen cat or message over print because
- cat returns invisible(NULL),
- message returns invisible()
- print returns a value, what it prints.
Can you adapt the code below to your use case?
TP <- 1:4
lapply(TP, function(x, verbose = TRUE){
# BODY
y <- rnorm(100, mean = x)
# show progress
if(verbose)
cat("x =", x, "x^2 =", x^2, "\n")
#return value
c(x = x, mean = mean(y))
})
lapply(TP, function(x, verbose = TRUE){
# BODY
y <- rnorm(100, mean = x)
# show progress
if(verbose) {
msg <- paste("x =", x, "x^2 =", x^2)
message(msg)
}
#return value
c(x = x, mean = mean(y))
})
Hope this helps,
Rui Barradas
Hello,
No, the x^2 are not printed after the i's. The x^2 are the function's
return values. The function prints the i's, then returns x^2.
As for your problem, it is now more clerar.
I would write a function accepting a url to take care of scraping and
call it in the lapply loop. The progress report can be in the loop, like
below.
This is a complete working example, scraping the Wikipedia list of
countries by GDP. The urls are in a list (it's always the same, I'm not
complicating things) and in a real scraping function I would wrap
tryCatch around it, just in case.
First the function, then the urls list, then the lapply loop.
library(rvest)
scrape <- function(url) {
page <- read_html(url)
gdp <- page |>
html_element(".wikitable") |>
html_table() |>
as.data.frame()
names(gdp) <- unlist(gdp[1,, drop = TRUE])
gdp <- gdp[-1,]
row.names(gdp) <- NULL
#return value
gdp
}
wiki_gdp_url <-
"https://en.wikipedia.org/wiki/List_of_countries_by_GDP_(nominal)"
urls_list <- list(wiki_gdp_url, wiki_gdp_url)
TP <- seq_along(urls_list)
TP
# [1] 1 2
df_list <- lapply(TP, \(i) {
URL <- urls_list[[i]]
data <- scrape(URL)
# show progress
message("iteration: ", i)
#return value
data
})
str(df_list)
Hope this helps,
Rui Barradas
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Re: [R] print and lapply....
Dear Akshay,
I think we have provided several solutions to the question asked. Can you
please adjust your question to more closely align with what you need. It would
be nice if you can provide sufficient detail so that we can see how you have
adapted our solutions and how these have not quite addressed this problem.
Tim
-Original Message-
From: R-help On Behalf Of akshay kulkarni
Sent: Monday, November 7, 2022 1:10 PM
To: Bert Gunter ; Andrew Simmons
Cc: R help Mailing list
Subject: Re: [R] print and lapply
[External Email]
Dear Bert,
Actually, I am replacing a big for loop by the lapply()
function, and report the progress:
lapply(TP, function(i) { BODY; print(i)})
Can you please adjust your solution in this light?
THanking you,
Yours sincerely,
AKSHAY M KULKARNI
From: Bert Gunter
Sent: Monday, November 7, 2022 11:16 PM
To: Andrew Simmons
Cc: akshay kulkarni ; R help Mailing list
Subject: Re: [R] print and lapply
Well... yes, of course. But assuming the sole purpose is to print the results
and not to save them for further processing, the OP's approach seems rather
painful. My preference would be to vectorize:
> print(cbind(TP, TPsq =TP^2), print.gap = 3)
TP TPsq
[1,]1 1
[2,]2 4
[3,]3 9
[4,]4 16
See ?print.default for details
-- Bert
On Mon, Nov 7, 2022 at 9:20 AM Andrew Simmons wrote:
>
> put print() around x^2
>
> On Mon, Nov 7, 2022, 12:18 akshay kulkarni wrote:
>
> > Dear members,
> > I have the following code and output:
> >
> > > TP <- 1:4
> > > lapply(TP,function(x){print(x);x^2})
> > [1] 1
> > [1] 2
> > [1] 3
> > [1] 4
> > [[1]]
> > [1] 1
> >
> > [[2]]
> > [1] 4
> >
> > [[3]]
> > [1] 9
> >
> > [[4]]
> > [1] 16
> >
> > How do I make the print function output x along with x^2, i.e not at
> > the beginning but before each of x^2?
> >
> > Many thanks in advance
> >
> > THanking you,
> > Yours sincerely
> > AKSHAY M KULKARNI
> >
> > [[alternative HTML version deleted]]
> >
> > __
> > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fst
> > at.ethz.ch%2Fmailman%2Flistinfo%2Fr-helpdata=05%7C01%7Ctebert%4
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> > 62331e1b84%7C0%7C0%7C638034414365456384%7CUnknown%7CTWFpbGZsb3d8eyJW
> > IjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C300
> > 0%7C%7C%7Csdata=dQk1JPxWI4D0D6%2FSoC8LWw56749ulaFrGQc6affgBeM%3
> > Dreserved=0
> > PLEASE do read the posting guide
> > https://nam10.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww
> > .r-project.org%2Fposting-guide.htmldata=05%7C01%7Ctebert%40ufl.
> > edu%7Cb726a89349ed4860265708dac0eb5d0a%7C0d4da0f84a314d76ace60a62331
> > e1b84%7C0%7C0%7C638034414365456384%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiM
> > C4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%
> > 7C%7Csdata=KDskHBxmxe0DV9XO7GvkESemUNTq2w%2BT%2Fro%2Bgb4DS2w%3D
> > reserved=0 and provide commented, minimal, self-contained,
> > reproducible code.
> >
>
> [[alternative HTML version deleted]]
>
> __
> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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> .ethz.ch%2Fmailman%2Flistinfo%2Fr-helpdata=05%7C01%7Ctebert%40ufl
> .edu%7Cb726a89349ed4860265708dac0eb5d0a%7C0d4da0f84a314d76ace60a62331e
> 1b84%7C0%7C0%7C638034414365456384%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4w
> LjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C
> sdata=dQk1JPxWI4D0D6%2FSoC8LWw56749ulaFrGQc6affgBeM%3Dreserv
> ed=0 PLEASE do read the posting guide
> https://nam10.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.r
> -project.org%2Fposting-guide.htmldata=05%7C01%7Ctebert%40ufl.edu%
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> 7C0%7C0%7C638034414365612626%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwM
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> sdata=OxZmpA4ORbfUq0gqM8ebZvK5bQTaiCwo0Y1ekn%2F3zBE%3Dreserved=0
> and provide commented, minimal, self-contained, reproducible code.
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Re: [R] print and lapply....
" The lapply() caches the result, and prints the output of the
function in question immediately after printing the final i. "
I don't believe you understand how lists or lapply works. You seem to
be trying to intuit from empirical behavior. Bad idea, if so. You need
to read the docs or spend time with suitable tutorials.
Consider:
lapply produces a **list,** each component of which is the result of
applying a function, FUN, to the components of its first argument
(here 1:4), which is itself a list. Results are **not** cached in the
sense you seem to think they are. The list object that is produced by
the function is **only** printed if you ask it to be (via cat, print,
or whatever) or, by default, if the result is unassigned. The default
printing can be turned off via the invisible() function.
So:
> res <- lapply(TP, function(x){
+print(x)
+x^2}
+)
[1] 1
[1] 2
[1] 3
[1] 4
[1] 5
## Nothing printed, but the results are the components of **list**
res, which can be printed on the console by print(res) or simply:
> res ## note the list syntax below
[[1]]
[1] 1
[[2]]
[1] 4
[[3]]
[1] 9
[[4]]
[1] 16
[[5]]
[1] 25
Now can you explain what happens here:
> invisible(lapply(TP, function(x){
+print(x)
+x^2}
+))
[1] 1
[1] 2
[1] 3
[1] 4
[1] 5
> ## results not printed; nothing assigned. Where can you find them? (See below)
or here:
> lapply(TP, function(x){
+print(x)
+x^2}
+)
[1] 1
[1] 2
[1] 3
[1] 4
[1] 5
[[1]]
[1] 1
[[2]]
[1] 4
[[3]]
[1] 9
[[4]]
[1] 16
[[5]]
[1] 25
## How could you recover the results of the lapply and not just look
at the console printout if the results have not been assigned?
## Hint: See ?.Last.value
-- Bert
On Mon, Nov 7, 2022 at 11:22 AM akshay kulkarni wrote:
>
> Dear Rui,
> THanks for your reply...The point is the loop is a scraping
> code, and in your examples you have assumed that the body acts on i, the loop
> variable. Can you adapt your code to JUST PRINT the loop variable i ?
>
> By the by, I think I have stumbled upon the answer: The lapply() caches the
> result, and prints the output of the function in question immediately after
> printing the final i. The i's get printed serially, as the function
> progresses
>
> > lapply(1:4,function(x){print(x);Sys.sleep(x^2);x^2})
> [1] 1
> [1] 2
> [1] 3
> [1] 4
> [[1]]
> [1] 1
>
> [[2]]
> [1] 4
>
> [[3]]
> [1] 9
>
> [[4]]
> [1] 16
>
> Here x^2 's print only after 4 is printed on the console
>
> tHanks anyways for your reply
>
> THanking you,
> Yours sincerely,
> AKSHAY M KULKARNI
> ____________
> From: Rui Barradas
> Sent: Tuesday, November 8, 2022 12:24 AM
> To: akshay kulkarni ; R help Mailing list
>
> Subject: Re: [R] print and lapply
>
> Às 18:33 de 07/11/2022, akshay kulkarni escreveu:
> > Dear Rui,
> > Actually, I am replacing a big for loop by the lapply()
> > function, and report the progress:
> >
> > lapply(TP, function(i) { BODY; print(i)})
> >
> > Can you please adjust your solution in this light?
> >
> > THanking you,
> > Yours sincerely,
> > AKSHAY M KULKARNI
> >
> > From: Rui Barradas
> > Sent: Monday, November 7, 2022 11:59 PM
> > To: akshay kulkarni ; R help Mailing list
> >
> > Subject: Re: [R] print and lapply
> >
> > Às 17:17 de 07/11/2022, akshay kulkarni escreveu:
> >> Dear members,
> >>I have the following code and output:
> >>
> >>> TP <- 1:4
> >>> lapply(TP,function(x){print(x);x^2})
> >> [1] 1
> >> [1] 2
> >> [1] 3
> >> [1] 4
> >> [[1]]
> >> [1] 1
> >>
> >> [[2]]
> >> [1] 4
> >>
> >> [[3]]
> >> [1] 9
> >>
> >> [[4]]
> >> [1] 16
> >>
> >> How do I make the print function output x along with x^2, i.e not at the
> >> beginning but before each of x^2?
> >>
> >> Many thanks in advance
> >>
> >> THanking you,
> >> Yours sincerely
> >> AKSHAY M KULKARNI
> >>
> >> [[alternative HTML version deleted]]
> >>
> >> __
> >> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> >> https://stat.ethz.ch/mailman/listinfo/r-help
> >> PLEASE do read the posting guide
> >> http://www.R-project.org/posting-guide.html
> >> and provide commented, minimal, self-contained, reproducible code.
> > Hello,
> >
> > Here are two options, with
Re: [R] print and lapply....
Dear Rui,
THanks for your reply...The point is the loop is a scraping
code, and in your examples you have assumed that the body acts on i, the loop
variable. Can you adapt your code to JUST PRINT the loop variable i ?
By the by, I think I have stumbled upon the answer: The lapply() caches the
result, and prints the output of the function in question immediately after
printing the final i. The i's get printed serially, as the function
progresses
> lapply(1:4,function(x){print(x);Sys.sleep(x^2);x^2})
[1] 1
[1] 2
[1] 3
[1] 4
[[1]]
[1] 1
[[2]]
[1] 4
[[3]]
[1] 9
[[4]]
[1] 16
Here x^2 's print only after 4 is printed on the console
tHanks anyways for your reply
THanking you,
Yours sincerely,
AKSHAY M KULKARNI
From: Rui Barradas
Sent: Tuesday, November 8, 2022 12:24 AM
To: akshay kulkarni ; R help Mailing list
Subject: Re: [R] print and lapply
�s 18:33 de 07/11/2022, akshay kulkarni escreveu:
> Dear Rui,
> Actually, I am replacing a big for loop by the lapply()
> function, and report the progress:
>
> lapply(TP, function(i) { BODY; print(i)})
>
> Can you please adjust your solution in this light?
>
> THanking you,
> Yours sincerely,
> AKSHAY M KULKARNI
>
> From: Rui Barradas
> Sent: Monday, November 7, 2022 11:59 PM
> To: akshay kulkarni ; R help Mailing list
>
> Subject: Re: [R] print and lapply
>
> �s 17:17 de 07/11/2022, akshay kulkarni escreveu:
>> Dear members,
>>I have the following code and output:
>>
>>> TP <- 1:4
>>> lapply(TP,function(x){print(x);x^2})
>> [1] 1
>> [1] 2
>> [1] 3
>> [1] 4
>> [[1]]
>> [1] 1
>>
>> [[2]]
>> [1] 4
>>
>> [[3]]
>> [1] 9
>>
>> [[4]]
>> [1] 16
>>
>> How do I make the print function output x along with x^2, i.e not at the
>> beginning but before each of x^2?
>>
>> Many thanks in advance
>>
>> THanking you,
>> Yours sincerely
>> AKSHAY M KULKARNI
>>
>> [[alternative HTML version deleted]]
>>
>> __
>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
> Hello,
>
> Here are two options, with ?cat and with ?message.
>
>
> TP <- 1:4
> lapply(TP, function(x){
> cat("x =", x, "x^2 =", x^2, "\n")
> })
>
> lapply(TP, function(x){
> msg <- paste("x =", x, "x^2 =", x^2)
> message(msg)
> })
>
>
> Hope this helps,
>
> Rui Barradas
>
>
>
Hello,
What do you want the lapply loop to return? If you have a BODY doing
computations, do you want the lapply to return those values and report
the progress?
I have chosen cat or message over print because
- cat returns invisible(NULL),
- message returns invisible()
- print returns a value, what it prints.
Can you adapt the code below to your use case?
TP <- 1:4
lapply(TP, function(x, verbose = TRUE){
# BODY
y <- rnorm(100, mean = x)
# show progress
if(verbose)
cat("x =", x, "x^2 =", x^2, "\n")
#return value
c(x = x, mean = mean(y))
})
lapply(TP, function(x, verbose = TRUE){
# BODY
y <- rnorm(100, mean = x)
# show progress
if(verbose) {
msg <- paste("x =", x, "x^2 =", x^2)
message(msg)
}
#return value
c(x = x, mean = mean(y))
})
Hope this helps,
Rui Barradas
[[alternative HTML version deleted]]
__
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] print and lapply....
Às 18:33 de 07/11/2022, akshay kulkarni escreveu:
Dear Rui,
Actually, I am replacing a big for loop by the lapply()
function, and report the progress:
lapply(TP, function(i) { BODY; print(i)})
Can you please adjust your solution in this light?
THanking you,
Yours sincerely,
AKSHAY M KULKARNI
From: Rui Barradas
Sent: Monday, November 7, 2022 11:59 PM
To: akshay kulkarni ; R help Mailing list
Subject: Re: [R] print and lapply
Às 17:17 de 07/11/2022, akshay kulkarni escreveu:
Dear members,
I have the following code and output:
TP <- 1:4
lapply(TP,function(x){print(x);x^2})
[1] 1
[1] 2
[1] 3
[1] 4
[[1]]
[1] 1
[[2]]
[1] 4
[[3]]
[1] 9
[[4]]
[1] 16
How do I make the print function output x along with x^2, i.e not at the
beginning but before each of x^2?
Many thanks in advance
THanking you,
Yours sincerely
AKSHAY M KULKARNI
[[alternative HTML version deleted]]
__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Hello,
Here are two options, with ?cat and with ?message.
TP <- 1:4
lapply(TP, function(x){
cat("x =", x, "x^2 =", x^2, "\n")
})
lapply(TP, function(x){
msg <- paste("x =", x, "x^2 =", x^2)
message(msg)
})
Hope this helps,
Rui Barradas
Hello,
What do you want the lapply loop to return? If you have a BODY doing
computations, do you want the lapply to return those values and report
the progress?
I have chosen cat or message over print because
- cat returns invisible(NULL),
- message returns invisible()
- print returns a value, what it prints.
Can you adapt the code below to your use case?
TP <- 1:4
lapply(TP, function(x, verbose = TRUE){
# BODY
y <- rnorm(100, mean = x)
# show progress
if(verbose)
cat("x =", x, "x^2 =", x^2, "\n")
#return value
c(x = x, mean = mean(y))
})
lapply(TP, function(x, verbose = TRUE){
# BODY
y <- rnorm(100, mean = x)
# show progress
if(verbose) {
msg <- paste("x =", x, "x^2 =", x^2)
message(msg)
}
#return value
c(x = x, mean = mean(y))
})
Hope this helps,
Rui Barradas
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Re: [R] print and lapply....
Dear Rui,
Actually, I am replacing a big for loop by the lapply()
function, and report the progress:
lapply(TP, function(i) { BODY; print(i)})
Can you please adjust your solution in this light?
THanking you,
Yours sincerely,
AKSHAY M KULKARNI
From: Rui Barradas
Sent: Monday, November 7, 2022 11:59 PM
To: akshay kulkarni ; R help Mailing list
Subject: Re: [R] print and lapply
�s 17:17 de 07/11/2022, akshay kulkarni escreveu:
> Dear members,
> I have the following code and output:
>
>> TP <- 1:4
>> lapply(TP,function(x){print(x);x^2})
> [1] 1
> [1] 2
> [1] 3
> [1] 4
> [[1]]
> [1] 1
>
> [[2]]
> [1] 4
>
> [[3]]
> [1] 9
>
> [[4]]
> [1] 16
>
> How do I make the print function output x along with x^2, i.e not at the
> beginning but before each of x^2?
>
> Many thanks in advance
>
> THanking you,
> Yours sincerely
> AKSHAY M KULKARNI
>
>[[alternative HTML version deleted]]
>
> __
> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
Hello,
Here are two options, with ?cat and with ?message.
TP <- 1:4
lapply(TP, function(x){
cat("x =", x, "x^2 =", x^2, "\n")
})
lapply(TP, function(x){
msg <- paste("x =", x, "x^2 =", x^2)
message(msg)
})
Hope this helps,
Rui Barradas
[[alternative HTML version deleted]]
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Re: [R] print and lapply....
Às 17:17 de 07/11/2022, akshay kulkarni escreveu:
Dear members,
I have the following code and output:
TP <- 1:4
lapply(TP,function(x){print(x);x^2})
[1] 1
[1] 2
[1] 3
[1] 4
[[1]]
[1] 1
[[2]]
[1] 4
[[3]]
[1] 9
[[4]]
[1] 16
How do I make the print function output x along with x^2, i.e not at the
beginning but before each of x^2?
Many thanks in advance
THanking you,
Yours sincerely
AKSHAY M KULKARNI
[[alternative HTML version deleted]]
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and provide commented, minimal, self-contained, reproducible code.
Hello,
Here are two options, with ?cat and with ?message.
TP <- 1:4
lapply(TP, function(x){
cat("x =", x, "x^2 =", x^2, "\n")
})
lapply(TP, function(x){
msg <- paste("x =", x, "x^2 =", x^2)
message(msg)
})
Hope this helps,
Rui Barradas
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Re: [R] print and lapply....
Dear Bert,
Actually, I am replacing a big for loop by the lapply()
function, and report the progress:
lapply(TP, function(i) { BODY; print(i)})
Can you please adjust your solution in this light?
THanking you,
Yours sincerely,
AKSHAY M KULKARNI
From: Bert Gunter
Sent: Monday, November 7, 2022 11:16 PM
To: Andrew Simmons
Cc: akshay kulkarni ; R help Mailing list
Subject: Re: [R] print and lapply
Well... yes, of course. But assuming the sole purpose is to print the
results and not to save them for further processing, the OP's approach
seems rather painful. My preference would be to vectorize:
> print(cbind(TP, TPsq =TP^2), print.gap = 3)
TP TPsq
[1,]1 1
[2,]2 4
[3,]3 9
[4,]4 16
See ?print.default for details
-- Bert
On Mon, Nov 7, 2022 at 9:20 AM Andrew Simmons wrote:
>
> put print() around x^2
>
> On Mon, Nov 7, 2022, 12:18 akshay kulkarni wrote:
>
> > Dear members,
> > I have the following code and output:
> >
> > > TP <- 1:4
> > > lapply(TP,function(x){print(x);x^2})
> > [1] 1
> > [1] 2
> > [1] 3
> > [1] 4
> > [[1]]
> > [1] 1
> >
> > [[2]]
> > [1] 4
> >
> > [[3]]
> > [1] 9
> >
> > [[4]]
> > [1] 16
> >
> > How do I make the print function output x along with x^2, i.e not at the
> > beginning but before each of x^2?
> >
> > Many thanks in advance
> >
> > THanking you,
> > Yours sincerely
> > AKSHAY M KULKARNI
> >
> > [[alternative HTML version deleted]]
> >
> > __
> > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide
> > http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
> >
>
> [[alternative HTML version deleted]]
>
> __
> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
[[alternative HTML version deleted]]
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Re: [R] print and lapply....
I meant something like:
TP <- 1:4
lapply(TP, function(x) {
print(x)
print(x^2)
})
You may wish to add cat("\n") after print(x^2) so that your results
from each iteration are separated.
You may also wish to add invisible() around lapply() if you're not
saving / / using the return list in any way.
On Mon, Nov 7, 2022 at 12:38 PM akshay kulkarni wrote:
>
> Dear Andrew
> It doesn't work:
>
> > lapply(TP,function(x){print(x^2)})
> [1] 1
> [1] 4
> [1] 9
> [1] 16
> [[1]]
> [1] 1
>
> [[2]]
> [1] 4
>
> [[3]]
> [1] 9
>
> [[4]]
> [1] 16
>
> Basically, lapply() is implemented by a for loop. So there must be some way
> right?
>
> tHanking you,
> Yours sincerely,
> AKSHAY M KULKARNI
>
> From: Andrew Simmons
> Sent: Monday, November 7, 2022 10:50 PM
> To: akshay kulkarni
> Cc: R help Mailing list
> Subject: Re: [R] print and lapply
>
> put print() around x^2
>
> On Mon, Nov 7, 2022, 12:18 akshay kulkarni wrote:
>
> Dear members,
> I have the following code and output:
>
> > TP <- 1:4
> > lapply(TP,function(x){print(x);x^2})
> [1] 1
> [1] 2
> [1] 3
> [1] 4
> [[1]]
> [1] 1
>
> [[2]]
> [1] 4
>
> [[3]]
> [1] 9
>
> [[4]]
> [1] 16
>
> How do I make the print function output x along with x^2, i.e not at the
> beginning but before each of x^2?
>
> Many thanks in advance
>
> THanking you,
> Yours sincerely
> AKSHAY M KULKARNI
>
> [[alternative HTML version deleted]]
>
> __
> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
__
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] print and lapply....
Dear Tim,
Actually, I am replacing a big for loop by the lapply()
function, and report the progress:
lapply(TP, function(i) { BODY; print(i)})
Can you please adjust your solution in this light?
THanking you,
Yours sincerely,
AKSHAY M KULKARNI
From: Ebert,Timothy Aaron
Sent: Monday, November 7, 2022 11:07 PM
To: Andrew Simmons ; akshay kulkarni
Cc: R help Mailing list
Subject: RE: [R] print and lapply
Another option is use paste() within print()
lapply(TP,function(x){print(paste("x= ",x, " x^2 = ", x^2))})
Tim
-Original Message-
From: R-help On Behalf Of Andrew Simmons
Sent: Monday, November 7, 2022 12:21 PM
To: akshay kulkarni
Cc: R help Mailing list
Subject: Re: [R] print and lapply
[External Email]
put print() around x^2
On Mon, Nov 7, 2022, 12:18 akshay kulkarni wrote:
> Dear members,
> I have the following code and output:
>
> > TP <- 1:4
> > lapply(TP,function(x){print(x);x^2})
> [1] 1
> [1] 2
> [1] 3
> [1] 4
> [[1]]
> [1] 1
>
> [[2]]
> [1] 4
>
> [[3]]
> [1] 9
>
> [[4]]
> [1] 16
>
> How do I make the print function output x along with x^2, i.e not at
> the beginning but before each of x^2?
>
> Many thanks in advance
>
> THanking you,
> Yours sincerely
> AKSHAY M KULKARNI
>
> [[alternative HTML version deleted]]
>
> __
> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fstat
> .ethz.ch%2Fmailman%2Flistinfo%2Fr-helpdata=05%7C01%7Ctebert%40ufl
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> sdata=1D8FQ07q2NcYL8PaJW84PqdUAte3pZJy8XJuJXENbJ4%3Dreserved
> =0
> PLEASE do read the posting guide
> https://nam10.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.r
> -project.org%2Fposting-guide.htmldata=05%7C01%7Ctebert%40ufl.edu%
> 7C28ae59febb2d43ce03b108dac0e46e79%7C0d4da0f84a314d76ace60a62331e1b84%
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> sdata=aEeZJ8FHVKGX%2BqOJaKskC1onjqKcON2Ux5cj3MimTGw%3Dreserved=0
> and provide commented, minimal, self-contained, reproducible code.
>
[[alternative HTML version deleted]]
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PLEASE do read the posting guide
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Re: [R] print and lapply....
Well... yes, of course. But assuming the sole purpose is to print the
results and not to save them for further processing, the OP's approach
seems rather painful. My preference would be to vectorize:
> print(cbind(TP, TPsq =TP^2), print.gap = 3)
TP TPsq
[1,]1 1
[2,]2 4
[3,]3 9
[4,]4 16
See ?print.default for details
-- Bert
On Mon, Nov 7, 2022 at 9:20 AM Andrew Simmons wrote:
>
> put print() around x^2
>
> On Mon, Nov 7, 2022, 12:18 akshay kulkarni wrote:
>
> > Dear members,
> > I have the following code and output:
> >
> > > TP <- 1:4
> > > lapply(TP,function(x){print(x);x^2})
> > [1] 1
> > [1] 2
> > [1] 3
> > [1] 4
> > [[1]]
> > [1] 1
> >
> > [[2]]
> > [1] 4
> >
> > [[3]]
> > [1] 9
> >
> > [[4]]
> > [1] 16
> >
> > How do I make the print function output x along with x^2, i.e not at the
> > beginning but before each of x^2?
> >
> > Many thanks in advance
> >
> > THanking you,
> > Yours sincerely
> > AKSHAY M KULKARNI
> >
> > [[alternative HTML version deleted]]
> >
> > __
> > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide
> > http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
> >
>
> [[alternative HTML version deleted]]
>
> __
> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
__
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Re: [R] print and lapply....
Dear Andrew
It doesn't work:
> lapply(TP,function(x){print(x^2)})
[1] 1
[1] 4
[1] 9
[1] 16
[[1]]
[1] 1
[[2]]
[1] 4
[[3]]
[1] 9
[[4]]
[1] 16
Basically, lapply() is implemented by a for loop. So there must be some way
right?
tHanking you,
Yours sincerely,
AKSHAY M KULKARNI
From: Andrew Simmons
Sent: Monday, November 7, 2022 10:50 PM
To: akshay kulkarni
Cc: R help Mailing list
Subject: Re: [R] print and lapply
put print() around x^2
On Mon, Nov 7, 2022, 12:18 akshay kulkarni
mailto:akshay...@hotmail.com>> wrote:
Dear members,
I have the following code and output:
> TP <- 1:4
> lapply(TP,function(x){print(x);x^2})
[1] 1
[1] 2
[1] 3
[1] 4
[[1]]
[1] 1
[[2]]
[1] 4
[[3]]
[1] 9
[[4]]
[1] 16
How do I make the print function output x along with x^2, i.e not at the
beginning but before each of x^2?
Many thanks in advance
THanking you,
Yours sincerely
AKSHAY M KULKARNI
[[alternative HTML version deleted]]
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[[alternative HTML version deleted]]
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Re: [R] print and lapply....
Another option is use paste() within print()
lapply(TP,function(x){print(paste("x= ",x, " x^2 = ", x^2))})
Tim
-Original Message-
From: R-help On Behalf Of Andrew Simmons
Sent: Monday, November 7, 2022 12:21 PM
To: akshay kulkarni
Cc: R help Mailing list
Subject: Re: [R] print and lapply
[External Email]
put print() around x^2
On Mon, Nov 7, 2022, 12:18 akshay kulkarni wrote:
> Dear members,
> I have the following code and output:
>
> > TP <- 1:4
> > lapply(TP,function(x){print(x);x^2})
> [1] 1
> [1] 2
> [1] 3
> [1] 4
> [[1]]
> [1] 1
>
> [[2]]
> [1] 4
>
> [[3]]
> [1] 9
>
> [[4]]
> [1] 16
>
> How do I make the print function output x along with x^2, i.e not at
> the beginning but before each of x^2?
>
> Many thanks in advance
>
> THanking you,
> Yours sincerely
> AKSHAY M KULKARNI
>
> [[alternative HTML version deleted]]
>
> __
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> LjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C
> sdata=1D8FQ07q2NcYL8PaJW84PqdUAte3pZJy8XJuJXENbJ4%3Dreserved
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> PLEASE do read the posting guide
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> 7C28ae59febb2d43ce03b108dac0e46e79%7C0d4da0f84a314d76ace60a62331e1b84%
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Re: [R] print and lapply....
put print() around x^2
On Mon, Nov 7, 2022, 12:18 akshay kulkarni wrote:
> Dear members,
> I have the following code and output:
>
> > TP <- 1:4
> > lapply(TP,function(x){print(x);x^2})
> [1] 1
> [1] 2
> [1] 3
> [1] 4
> [[1]]
> [1] 1
>
> [[2]]
> [1] 4
>
> [[3]]
> [1] 9
>
> [[4]]
> [1] 16
>
> How do I make the print function output x along with x^2, i.e not at the
> beginning but before each of x^2?
>
> Many thanks in advance
>
> THanking you,
> Yours sincerely
> AKSHAY M KULKARNI
>
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>
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> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
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__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
