Re: [R] loops and if statements
I would prefer version 1.
Version to creates a global variable R which you do not really need
since it contains the same values as d$r.
In option 2, you should probably remove the variable r itself
after it has been appended to d.
On 4/18/2010 5:23 PM, Laura Ferrero-Miliani wrote:
> Thanks for correcting my code Erich, do you think what I wrote is
> overcomplicating things? Considering what Juan wrote:
>
> # Option 1
> a <- 1:4
> b <- c("meep", "foo", "meep", "foo")
> d <- data.frame(a, b)
> d$r <- with(d, ifelse(b == 'meep', 'oops', 'yay'))
> d
>
> # Option 2
> a <- 1:4
> b <- c("meep", "foo", "meep", "foo")
> d <- cbind(a, b)
> r <- ifelse(d[,2] == 'meep', 'oops', 'yay')
> d <- cbind(d, r)
> d
>
>
> On Sun, Apr 18, 2010 at 5:13 PM, Erich Neuwirth
> wrote:
>>> for(i in seq(along=d[,2])) {if (d[i,2]=="meep") { print("oops")}
>>> else { print("yay")}
>>> }
>> is probably what you want.
>> But the way you are using cbind converts a into a vector of
>> character. It is not numeric any more.
>> Perhaps you want
>>
>> d<-cbind(as.data.frame(a),b)
>>
>> And then you could do
>>
>> for (el in d$b) print(ifelse(el=="meep","oops","yay"))
>>
>> On 4/18/2010 2:46 PM, Laura Ferrero-Miliani wrote:
>>> for(i in seq(along=d[,2])) {if (d[i]=="meep") { print("oops")}
>>> else { print("yay")}
>>> }
>>
>> --
>> Erich Neuwirth, University of Vienna
>> Faculty of Computer Science
>> Computer Supported Didactics Working Group
>> Visit our SunSITE at http://sunsite.univie.ac.at
>> Phone: +43-1-4277-39464 Fax: +43-1-4277-39459
>>
>
>
--
Erich Neuwirth, University of Vienna
Faculty of Computer Science
Computer Supported Didactics Working Group
Visit our SunSITE at http://sunsite.univie.ac.at
Phone: +43-1-4277-39464 Fax: +43-1-4277-39459
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Re: [R] loops and if statements
Thank you so much all!
How a simple problem can get complicated by not having enough
knowledge, but hopefully I am learning
Have a great Sunday!
L
On Sun, Apr 18, 2010 at 4:56 PM, jim holtman wrote:
> You are working with a matrix, so the "$" operator is not allowed (e.g.,
> d$c).
>
> Also in your test, you have to test against the second column (e.g., d[i,
> 2])
>
> try this:
>
>> a <- c(1:4)
>> b <- c("meep", "foo", "meep", "foo")
>> d <- cbind(a, b)
>>
>>
>> for(i in seq(along=d[,2])) {if (d[i,2]=="meep") { print("oops")}
> + else { print("yay")}
> + }
> [1] "oops"
> [1] "yay"
> [1] "oops"
> [1] "yay"
>>
>> # put results back
>> d <- cbind(d, c=ifelse(d[,2] == 'meep', 'oops', 'yay'))
>> d
> a b c
> [1,] "1" "meep" "oops"
> [2,] "2" "foo" "yay"
> [3,] "3" "meep" "oops"
> [4,] "4" "foo" "yay"
>>
>
>
> On Sun, Apr 18, 2010 at 8:46 AM, Laura Ferrero-Miliani
> wrote:
>>
>> Hello,
>> I am very new to R and data analysis in general.
>> I am trying to generate values to append to my data frame using
>> conditional statements.
>> I am playing with this simple example:
>>
>> a <- c(1:4)
>> b <- c("meep", "foo", "meep", "foo")
>> d <- cbind(a, b)
>>
>> now what I want to do is , each time there is a "meep" in column 2 of
>> d, print "oops", else print "yay".
>> So I wrote:
>>
>> for(i in seq(along=d[,2])) {if (d[i]=="meep") { print("oops")}
>> else { print("yay")}
>> }
>>
>> Result:
>> [1] "yay"
>> [1] "yay"
>> [1] "yay"
>> [1] "yay"
>>
>> What am I doing wrong?
>>
>> Furthermore, I would like to append the results to d:
>>
>> d$c <- for(i in seq(along=d[,2])) {if (d[i]=="meep") { print("oops")}
>> else { print("yay")}
>> }
>>
>>
>> this doesn't really work, it just turns the whole thing into a list.
>> .
>> Although if:
>>
>> c <- NA
>> d <- cbind(a, b, c)
>>
>> and I coerce d into a data.frame, run:
>>
>> d$c <- for(i in seq(along=d[,2])) {if (d[i]=="meep") { print("oops")}
>> else { print("yay")}
>> }
>>
>>
>> some glint of hope appears:
>>
>>
>> [1] "yay"
>> [1] "oops"
>>
>> but then..
>>
>>
>>
>> Error in if (d[i] == "meep") { : missing value where TRUE/FALSE needed
>> In addition: Warning messages:
>> 1: In if (d[i] == "meep") { :
>> the condition has length > 1 and only the first element will be used
>> 2: In if (d[i] == "meep") { :
>> the condition has length > 1 and only the first element will be used
>> 3: In if (d[i] == "meep") { :
>> the condition has length > 1 and only the first element will be used
>>
>>
>> To complicate things a little bit more in my real data there are 16
>> levels, so for each level I need to "print" a different value (that
>> would be 16 nested ifs, and I am sure there must be a more sensible
>> way to do this!)
>>
>>
>> Thanks in advance,
>>
>> Laura
>>
>> __
>> R-help@r-project.org mailing list
>> 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.
>
>
>
> --
> Jim Holtman
> Cincinnati, OH
> +1 513 646 9390
>
> What is the problem that you are trying to solve?
>
__
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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] loops and if statements
Hey Laura,
Just to add a cautionary note, in
> a <- c(1:4)
> b <- c("meep", "foo", "meep", "foo")
> d <- cbind(a, b)
d is a matrix and will only be one type of matrix. Since you have
both integer (a) and character (b) data, it has to be at the character
level. From the help for cbind:
"The type of a matrix result determined from the highest type of any
of the inputs in the hierarchy raw < logical < integer < real <
complex < character < list"
This means that the first column of 1:4 is now treated as character.
That may not be what you were intending. You can get around this by
creating a dataframe which can store different types of data.
Best regards,
Josh
--
Joshua Wiley
Senior in Psychology
University of California, Riverside
http://www.joshuawiley.com/
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and provide commented, minimal, self-contained, reproducible code.
Re: [R] loops and if statements
You are working with a matrix, so the "$" operator is not allowed (e.g.,
d$c).
Also in your test, you have to test against the second column (e.g., d[i,
2])
try this:
> a <- c(1:4)
> b <- c("meep", "foo", "meep", "foo")
> d <- cbind(a, b)
>
>
> for(i in seq(along=d[,2])) {if (d[i,2]=="meep") { print("oops")}
+else { print("yay")}
+ }
[1] "oops"
[1] "yay"
[1] "oops"
[1] "yay"
>
> # put results back
> d <- cbind(d, c=ifelse(d[,2] == 'meep', 'oops', 'yay'))
> d
a b c
[1,] "1" "meep" "oops"
[2,] "2" "foo" "yay"
[3,] "3" "meep" "oops"
[4,] "4" "foo" "yay"
>
On Sun, Apr 18, 2010 at 8:46 AM, Laura Ferrero-Miliani wrote:
> Hello,
> I am very new to R and data analysis in general.
> I am trying to generate values to append to my data frame using
> conditional statements.
> I am playing with this simple example:
>
> a <- c(1:4)
> b <- c("meep", "foo", "meep", "foo")
> d <- cbind(a, b)
>
> now what I want to do is , each time there is a "meep" in column 2 of
> d, print "oops", else print "yay".
> So I wrote:
>
> for(i in seq(along=d[,2])) {if (d[i]=="meep") { print("oops")}
>else { print("yay")}
> }
>
> Result:
> [1] "yay"
> [1] "yay"
> [1] "yay"
> [1] "yay"
>
> What am I doing wrong?
>
> Furthermore, I would like to append the results to d:
>
> d$c <- for(i in seq(along=d[,2])) {if (d[i]=="meep") { print("oops")}
>else { print("yay")}
> }
>
>
> this doesn't really work, it just turns the whole thing into a list.
> .
> Although if:
>
> c <- NA
> d <- cbind(a, b, c)
>
> and I coerce d into a data.frame, run:
>
> d$c <- for(i in seq(along=d[,2])) {if (d[i]=="meep") { print("oops")}
>else { print("yay")}
> }
>
>
> some glint of hope appears:
>
>
> [1] "yay"
> [1] "oops"
>
> but then..
>
>
>
> Error in if (d[i] == "meep") { : missing value where TRUE/FALSE needed
> In addition: Warning messages:
> 1: In if (d[i] == "meep") { :
> the condition has length > 1 and only the first element will be used
> 2: In if (d[i] == "meep") { :
> the condition has length > 1 and only the first element will be used
> 3: In if (d[i] == "meep") { :
> the condition has length > 1 and only the first element will be used
>
>
> To complicate things a little bit more in my real data there are 16
> levels, so for each level I need to "print" a different value (that
> would be 16 nested ifs, and I am sure there must be a more sensible
> way to do this!)
>
>
> Thanks in advance,
>
> Laura
>
> __
> R-help@r-project.org mailing list
> 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.
>
--
Jim Holtman
Cincinnati, OH
+1 513 646 9390
What is the problem that you are trying to solve?
[[alternative HTML version deleted]]
__
R-help@r-project.org mailing list
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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.
[R] loops and if statements
Hello,
I am very new to R and data analysis in general.
I am trying to generate values to append to my data frame using
conditional statements.
I am playing with this simple example:
a <- c(1:4)
b <- c("meep", "foo", "meep", "foo")
d <- cbind(a, b)
now what I want to do is , each time there is a "meep" in column 2 of
d, print "oops", else print "yay".
So I wrote:
for(i in seq(along=d[,2])) {if (d[i]=="meep") { print("oops")}
else { print("yay")}
}
Result:
[1] "yay"
[1] "yay"
[1] "yay"
[1] "yay"
What am I doing wrong?
Furthermore, I would like to append the results to d:
d$c <- for(i in seq(along=d[,2])) {if (d[i]=="meep") { print("oops")}
else { print("yay")}
}
this doesn't really work, it just turns the whole thing into a list.
.
Although if:
c <- NA
d <- cbind(a, b, c)
and I coerce d into a data.frame, run:
d$c <- for(i in seq(along=d[,2])) {if (d[i]=="meep") { print("oops")}
else { print("yay")}
}
some glint of hope appears:
[1] "yay"
[1] "oops"
but then..
Error in if (d[i] == "meep") { : missing value where TRUE/FALSE needed
In addition: Warning messages:
1: In if (d[i] == "meep") { :
the condition has length > 1 and only the first element will be used
2: In if (d[i] == "meep") { :
the condition has length > 1 and only the first element will be used
3: In if (d[i] == "meep") { :
the condition has length > 1 and only the first element will be used
To complicate things a little bit more in my real data there are 16
levels, so for each level I need to "print" a different value (that
would be 16 nested ifs, and I am sure there must be a more sensible
way to do this!)
Thanks in advance,
Laura
__
R-help@r-project.org mailing list
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.
