Re: [R] preserve class in apply function
Also try
apply(Filter(is.numeric, mydf), 1, sum)
On Tue, Feb 7, 2023 at 8:42 AM PIKAL Petr wrote:
>
> Hi Naresh
>
> If you wanted to automate the function a bit you can use sapply to find
> numeric columns
> ind <- sapply(mydf, is.numeric)
>
> and use it in apply construct
> apply(mydf[,ind], 1, function(row) sum(row))
> [1] 2.13002569 0.63305300 1.48420429 0.13523859 1.17515873 -0.98531131
> [7] 0.47044467 0.23914494 0.26504430 0.02037657
>
> Cheers
> Petr
>
> > -Original Message-
> > From: R-help On Behalf Of Naresh Gurbuxani
> > Sent: Tuesday, February 7, 2023 1:52 PM
> > To: r-help@r-project.org
> > Subject: [R] preserve class in apply function
> >
> >
> > > Consider a data.frame whose different columns have numeric, character,
> > > and factor data. In apply function, R seems to pass all elements of a
> > > row as character. Is it possible to preserve numeric class?
> > >
> > >> mydf <- data.frame(x = rnorm(10), y = runif(10))
> > >> apply(mydf, 1, function(row) {row["x"] + row["y"]})
> > > [1] 0.60150197 -0.74201827 0.80476392 -0.59729280 -0.02980335
> > 0.31351909
> > > [7] -0.63575990 0.22670658 0.55696314 0.39587314
> > >> mydf[, "z"] <- sample(letters[1:3], 10, replace = TRUE)
> > >> apply(mydf, 1, function(row) {row["x"] + row["y"]})
> > > Error in row["x"] + row["y"] (from #1) : non-numeric argument to binary
> > operator
> > >> apply(mydf, 1, function(row) {as.numeric(row["x"]) +
> > as.numeric(row["y"])})
> > > [1] 0.60150194 -0.74201826 0.80476394 -0.59729282 -0.02980338
> > 0.31351912
> > > [7] -0.63575991 0.22670663 0.55696309 0.39587311
> > >> apply(mydf[,c("x", "y")], 1, function(row) {row["x"] + row["y"]})
> > > [1] 0.60150197 -0.74201827 0.80476392 -0.59729280 -0.02980335
> > 0.31351909
> > > [7] -0.63575990 0.22670658 0.55696314 0.39587314
> >
> > __
> > 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.
> __
> 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.
--
Statistics & Software Consulting
GKX Group, GKX Associates Inc.
tel: 1-877-GKX-GROUP
email: ggrothendieck at gmail.com
__
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.
Re: [R] preserve class in apply function
Jorgen is correct that for many purposes, viewing a data.frame as a
collection of vectors of the same length allows you to code fairly complex
logic using whichever vectors you want and result in a vector answer, either
externally or as a new column. Text columns used to make some decisions in
the function are also usable using vectorized functions like ifelse(cond,
when_true, when_false).
And, although much can be done in base R, people often use the
dplyr/tidyverse function of mutate() to do such calculations in a slightly
less wordy way.
You may be looking at apply() as a way to operate one row at a time when an
R paradigm is to be able to operate on all rows sort of at once.
-Original Message-
From: R-help On Behalf Of Jorgen Harmse via
R-help
Sent: Wednesday, February 8, 2023 11:10 AM
To: r-help@r-project.org; naresh_gurbux...@hotmail.com
Subject: Re: [R] preserve class in apply function
What are you trying to do? Why use apply when there is already a vector
addition operation?
df$x+df$y or as.numeric(df$x)+as.numeric(df$y) or
rowSums(as.numeric(df[c('x','y')])).
As noted in other answers, apply will coerce your data frame to a matrix,
and all entries of a matrix must have the same type.
Regards,
Jorgen Harmse.
Message: 1
Date: Tue, 7 Feb 2023 07:51:50 -0500
From: Naresh Gurbuxani
To: "r-help@r-project.org"
Subject: [R] preserve class in apply function
Message-ID:
Content-Type: text/plain; charset="us-ascii"
> Consider a data.frame whose different columns have numeric, character,
> and factor data. In apply function, R seems to pass all elements of a
> row as character. Is it possible to preserve numeric class?
>
>> mydf <- data.frame(x = rnorm(10), y = runif(10)) apply(mydf, 1,
>> function(row) {row["x"] + row["y"]})
> [1] 0.60150197 -0.74201827 0.80476392 -0.59729280 -0.02980335
> 0.31351909 [7] -0.63575990 0.22670658 0.55696314 0.39587314
>> mydf[, "z"] <- sample(letters[1:3], 10, replace = TRUE) apply(mydf,
>> 1, function(row) {row["x"] + row["y"]})
> Error in row["x"] + row["y"] (from #1) : non-numeric argument to
> binary operator
>> apply(mydf, 1, function(row) {as.numeric(row["x"]) +
>> as.numeric(row["y"])})
> [1] 0.60150194 -0.74201826 0.80476394 -0.59729282 -0.02980338
> 0.31351912 [7] -0.63575991 0.22670663 0.55696309 0.39587311
>> apply(mydf[,c("x", "y")], 1, function(row) {row["x"] + row["y"]})
> [1] 0.60150197 -0.74201827 0.80476392 -0.59729280 -0.02980335
> 0.31351909 [7] -0.63575990 0.22670658 0.55696314 0.39587314
[[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.
__
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.
Re: [R] preserve class in apply function
Naresh,
This is a common case where the answer to a question is to ask the right
question.
Your question was how to make apply work. My question is how can you get the
functionality you want done in some version of R.
Apply is a tool and it is only one of many tools and may be the wrong one for
your task.
For a data.frame there can be lots of tools you may investigate both in vase R
and add-on packages like dplyr in the tidyverse.
As has been pointed out, a side-effect of apply is to make a matrix and R
automagically figures out what the most specific kind of data type it can
handle.
So solutions range from not including any columns that are not numeric, if that
makes sense, to accepting they are all going to be of type character and in the
function you apply, convert them individually back to what you want.
One straightforward solution is to make a loop indexed to the number of rows in
your data.frame and process the variables in each row using [] notation. Not
fast, but you see what you have.
Another is functions like pmap() in the purr package. Yet another might be the
rowwise() function in the dplyr package.
It depends on what you want to do. Note with multiple columns, sometimes your
function may need to use a ... to receive them.
-Original Message-
From: R-help On Behalf Of Naresh Gurbuxani
Sent: Tuesday, February 7, 2023 3:29 PM
To: PIKAL Petr
Cc: r-help@r-project.org
Subject: Re: [R] preserve class in apply function
Thanks for all the responses. I need to use some text columns to determine
method applied to numeric columns.
Split seems to be the way to go.
Sent from my iPhone
> On Feb 7, 2023, at 8:31 AM, PIKAL Petr wrote:
>
> Hi Naresh
>
> If you wanted to automate the function a bit you can use sapply to
> find numeric columns ind <- sapply(mydf, is.numeric)
>
> and use it in apply construct
> apply(mydf[,ind], 1, function(row) sum(row)) [1] 2.13002569
> 0.63305300 1.48420429 0.13523859 1.17515873 -0.98531131 [7]
> 0.47044467 0.23914494 0.26504430 0.02037657
>
> Cheers
> Petr
>
>> -Original Message-
>> From: R-help On Behalf Of Naresh
>> Gurbuxani
>> Sent: Tuesday, February 7, 2023 1:52 PM
>> To: r-help@r-project.org
>> Subject: [R] preserve class in apply function
>>
>>
>>> Consider a data.frame whose different columns have numeric,
>>> character, and factor data. In apply function, R seems to pass all
>>> elements of a row as character. Is it possible to preserve numeric class?
>>>
>>>> mydf <- data.frame(x = rnorm(10), y = runif(10)) apply(mydf, 1,
>>>> function(row) {row["x"] + row["y"]})
>>> [1] 0.60150197 -0.74201827 0.80476392 -0.59729280 -0.02980335
>> 0.31351909
>>> [7] -0.63575990 0.22670658 0.55696314 0.39587314
>>>> mydf[, "z"] <- sample(letters[1:3], 10, replace = TRUE) apply(mydf,
>>>> 1, function(row) {row["x"] + row["y"]})
>>> Error in row["x"] + row["y"] (from #1) : non-numeric argument to
>>> binary
>> operator
>>>> apply(mydf, 1, function(row) {as.numeric(row["x"]) +
>> as.numeric(row["y"])})
>>> [1] 0.60150194 -0.74201826 0.80476394 -0.59729282 -0.02980338
>> 0.31351912
>>> [7] -0.63575991 0.22670663 0.55696309 0.39587311
>>>> apply(mydf[,c("x", "y")], 1, function(row) {row["x"] + row["y"]})
>>> [1] 0.60150197 -0.74201827 0.80476392 -0.59729280 -0.02980335
>> 0.31351909
>>> [7] -0.63575990 0.22670658 0.55696314 0.39587314
>>
>> __
>> 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.
__
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.
__
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.
Re: [R] preserve class in apply function
What are you trying to do? Why use apply when there is already a vector
addition operation?
df$x+df$y or as.numeric(df$x)+as.numeric(df$y) or
rowSums(as.numeric(df[c('x','y')])).
As noted in other answers, apply will coerce your data frame to a matrix, and
all entries of a matrix must have the same type.
Regards,
Jorgen Harmse.
Message: 1
Date: Tue, 7 Feb 2023 07:51:50 -0500
From: Naresh Gurbuxani
To: "r-help@r-project.org"
Subject: [R] preserve class in apply function
Message-ID:
Content-Type: text/plain; charset="us-ascii"
> Consider a data.frame whose different columns have numeric, character,
> and factor data. In apply function, R seems to pass all elements of a
> row as character. Is it possible to preserve numeric class?
>
>> mydf <- data.frame(x = rnorm(10), y = runif(10))
>> apply(mydf, 1, function(row) {row["x"] + row["y"]})
> [1] 0.60150197 -0.74201827 0.80476392 -0.59729280 -0.02980335 0.31351909
> [7] -0.63575990 0.22670658 0.55696314 0.39587314
>> mydf[, "z"] <- sample(letters[1:3], 10, replace = TRUE)
>> apply(mydf, 1, function(row) {row["x"] + row["y"]})
> Error in row["x"] + row["y"] (from #1) : non-numeric argument to binary
> operator
>> apply(mydf, 1, function(row) {as.numeric(row["x"]) + as.numeric(row["y"])})
> [1] 0.60150194 -0.74201826 0.80476394 -0.59729282 -0.02980338 0.31351912
> [7] -0.63575991 0.22670663 0.55696309 0.39587311
>> apply(mydf[,c("x", "y")], 1, function(row) {row["x"] + row["y"]})
> [1] 0.60150197 -0.74201827 0.80476392 -0.59729280 -0.02980335 0.31351909
> [7] -0.63575990 0.22670658 0.55696314 0.39587314
[[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.
Re: [R] preserve class in apply function
Thanks for all the responses. I need to use some text columns to determine
method applied to numeric columns.
Split seems to be the way to go.
Sent from my iPhone
> On Feb 7, 2023, at 8:31 AM, PIKAL Petr wrote:
>
> Hi Naresh
>
> If you wanted to automate the function a bit you can use sapply to find
> numeric columns
> ind <- sapply(mydf, is.numeric)
>
> and use it in apply construct
> apply(mydf[,ind], 1, function(row) sum(row))
> [1] 2.13002569 0.63305300 1.48420429 0.13523859 1.17515873 -0.98531131
> [7] 0.47044467 0.23914494 0.26504430 0.02037657
>
> Cheers
> Petr
>
>> -Original Message-
>> From: R-help On Behalf Of Naresh Gurbuxani
>> Sent: Tuesday, February 7, 2023 1:52 PM
>> To: r-help@r-project.org
>> Subject: [R] preserve class in apply function
>>
>>
>>> Consider a data.frame whose different columns have numeric, character,
>>> and factor data. In apply function, R seems to pass all elements of a
>>> row as character. Is it possible to preserve numeric class?
>>>
>>>> mydf <- data.frame(x = rnorm(10), y = runif(10))
>>>> apply(mydf, 1, function(row) {row["x"] + row["y"]})
>>> [1] 0.60150197 -0.74201827 0.80476392 -0.59729280 -0.02980335
>> 0.31351909
>>> [7] -0.63575990 0.22670658 0.55696314 0.39587314
>>>> mydf[, "z"] <- sample(letters[1:3], 10, replace = TRUE)
>>>> apply(mydf, 1, function(row) {row["x"] + row["y"]})
>>> Error in row["x"] + row["y"] (from #1) : non-numeric argument to binary
>> operator
>>>> apply(mydf, 1, function(row) {as.numeric(row["x"]) +
>> as.numeric(row["y"])})
>>> [1] 0.60150194 -0.74201826 0.80476394 -0.59729282 -0.02980338
>> 0.31351912
>>> [7] -0.63575991 0.22670663 0.55696309 0.39587311
>>>> apply(mydf[,c("x", "y")], 1, function(row) {row["x"] + row["y"]})
>>> [1] 0.60150197 -0.74201827 0.80476392 -0.59729280 -0.02980335
>> 0.31351909
>>> [7] -0.63575990 0.22670658 0.55696314 0.39587314
>>
>> __
>> 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.
__
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.
Re: [R] preserve class in apply function
Hi Naresh
If you wanted to automate the function a bit you can use sapply to find
numeric columns
ind <- sapply(mydf, is.numeric)
and use it in apply construct
apply(mydf[,ind], 1, function(row) sum(row))
[1] 2.13002569 0.63305300 1.48420429 0.13523859 1.17515873 -0.98531131
[7] 0.47044467 0.23914494 0.26504430 0.02037657
Cheers
Petr
> -Original Message-
> From: R-help On Behalf Of Naresh Gurbuxani
> Sent: Tuesday, February 7, 2023 1:52 PM
> To: r-help@r-project.org
> Subject: [R] preserve class in apply function
>
>
> > Consider a data.frame whose different columns have numeric, character,
> > and factor data. In apply function, R seems to pass all elements of a
> > row as character. Is it possible to preserve numeric class?
> >
> >> mydf <- data.frame(x = rnorm(10), y = runif(10))
> >> apply(mydf, 1, function(row) {row["x"] + row["y"]})
> > [1] 0.60150197 -0.74201827 0.80476392 -0.59729280 -0.02980335
> 0.31351909
> > [7] -0.63575990 0.22670658 0.55696314 0.39587314
> >> mydf[, "z"] <- sample(letters[1:3], 10, replace = TRUE)
> >> apply(mydf, 1, function(row) {row["x"] + row["y"]})
> > Error in row["x"] + row["y"] (from #1) : non-numeric argument to binary
> operator
> >> apply(mydf, 1, function(row) {as.numeric(row["x"]) +
> as.numeric(row["y"])})
> > [1] 0.60150194 -0.74201826 0.80476394 -0.59729282 -0.02980338
> 0.31351912
> > [7] -0.63575991 0.22670663 0.55696309 0.39587311
> >> apply(mydf[,c("x", "y")], 1, function(row) {row["x"] + row["y"]})
> > [1] 0.60150197 -0.74201827 0.80476392 -0.59729280 -0.02980335
> 0.31351909
> > [7] -0.63575990 0.22670658 0.55696314 0.39587314
>
> __
> 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.
__
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.
Re: [R] preserve class in apply function
Às 12:51 de 07/02/2023, Naresh Gurbuxani escreveu:
Consider a data.frame whose different columns have numeric, character,
and factor data. In apply function, R seems to pass all elements of a
row as character. Is it possible to preserve numeric class?
mydf <- data.frame(x = rnorm(10), y = runif(10))
apply(mydf, 1, function(row) {row["x"] + row["y"]})
[1] 0.60150197 -0.74201827 0.80476392 -0.59729280 -0.02980335 0.31351909
[7] -0.63575990 0.22670658 0.55696314 0.39587314
mydf[, "z"] <- sample(letters[1:3], 10, replace = TRUE)
apply(mydf, 1, function(row) {row["x"] + row["y"]})
Error in row["x"] + row["y"] (from #1) : non-numeric argument to binary operator
apply(mydf, 1, function(row) {as.numeric(row["x"]) + as.numeric(row["y"])})
[1] 0.60150194 -0.74201826 0.80476394 -0.59729282 -0.02980338 0.31351912
[7] -0.63575991 0.22670663 0.55696309 0.39587311
apply(mydf[,c("x", "y")], 1, function(row) {row["x"] + row["y"]})
[1] 0.60150197 -0.74201827 0.80476392 -0.59729280 -0.02980335 0.31351909
[7] -0.63575990 0.22670658 0.55696314 0.39587314
__
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,
The last form,
apply(mydf[,c("x", "y")], 1, function(row) {row["x"] + row["y"]})
is the right one. If your data has columns of a mix of classes, then the
rows which are vectors are coerced to the greatest common denominator
class.
From ?c:
Details
The output type is determined from the highest type of the components in
the hierarchy NULL < raw < logical < integer < double < complex <
character < list < expression.
Also, since you have a data.frame the following is another possible way:
apply(mydf[c("x", "y")], 1, function(row) {row["x"] + row["y"]})
This doesn't work with matrices.
Hope this helps,
Rui Barradas
__
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.
Re: [R] preserve class in apply function
It is not possible, apply() converts its argument to an array. You might be
able to use split() and lapply() to solve your problem.
On Tue, Feb 7, 2023, 07:52 Naresh Gurbuxani
wrote:
>
> > Consider a data.frame whose different columns have numeric, character,
> > and factor data. In apply function, R seems to pass all elements of a
> > row as character. Is it possible to preserve numeric class?
> >
> >> mydf <- data.frame(x = rnorm(10), y = runif(10))
> >> apply(mydf, 1, function(row) {row["x"] + row["y"]})
> > [1] 0.60150197 -0.74201827 0.80476392 -0.59729280 -0.02980335
> 0.31351909
> > [7] -0.63575990 0.22670658 0.55696314 0.39587314
> >> mydf[, "z"] <- sample(letters[1:3], 10, replace = TRUE)
> >> apply(mydf, 1, function(row) {row["x"] + row["y"]})
> > Error in row["x"] + row["y"] (from #1) : non-numeric argument to binary
> operator
> >> apply(mydf, 1, function(row) {as.numeric(row["x"]) +
> as.numeric(row["y"])})
> > [1] 0.60150194 -0.74201826 0.80476394 -0.59729282 -0.02980338
> 0.31351912
> > [7] -0.63575991 0.22670663 0.55696309 0.39587311
> >> apply(mydf[,c("x", "y")], 1, function(row) {row["x"] + row["y"]})
> > [1] 0.60150197 -0.74201827 0.80476392 -0.59729280 -0.02980335
> 0.31351909
> > [7] -0.63575990 0.22670658 0.55696314 0.39587314
>
> __
> 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.
[R] preserve class in apply function
> Consider a data.frame whose different columns have numeric, character,
> and factor data. In apply function, R seems to pass all elements of a
> row as character. Is it possible to preserve numeric class?
>
>> mydf <- data.frame(x = rnorm(10), y = runif(10))
>> apply(mydf, 1, function(row) {row["x"] + row["y"]})
> [1] 0.60150197 -0.74201827 0.80476392 -0.59729280 -0.02980335 0.31351909
> [7] -0.63575990 0.22670658 0.55696314 0.39587314
>> mydf[, "z"] <- sample(letters[1:3], 10, replace = TRUE)
>> apply(mydf, 1, function(row) {row["x"] + row["y"]})
> Error in row["x"] + row["y"] (from #1) : non-numeric argument to binary
> operator
>> apply(mydf, 1, function(row) {as.numeric(row["x"]) + as.numeric(row["y"])})
> [1] 0.60150194 -0.74201826 0.80476394 -0.59729282 -0.02980338 0.31351912
> [7] -0.63575991 0.22670663 0.55696309 0.39587311
>> apply(mydf[,c("x", "y")], 1, function(row) {row["x"] + row["y"]})
> [1] 0.60150197 -0.74201827 0.80476392 -0.59729280 -0.02980335 0.31351909
> [7] -0.63575990 0.22670658 0.55696314 0.39587314
__
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.
