Hello,
I apologize in advance for not providing sample data, I'm a very new to R
and can't easily generate appropriate sample data quickly. I'm hoping
someone can offer advice without it.
This code below works and does what I want it to do, which is for a given
row in my dataframe, where the variable "peak.cort" = max, it makes
the
value of another variable "max.cort" = to match the value of a third
variable "cortisol" for that row.
*************
index <- raw.saliva.data$peak.cort == 'max'
raw.saliva.data$max.cort[index] <-
(raw.saliva.data$cortisol[index])
*************
Now, I want to execute this function only if the value of a fourth
variable, "sample" is >1 and <5. I tried to add an ifelse
statement to the
code above so that it looks like this:
*************
index <- raw.saliva.data$peak.cort == 'max'
raw.saliva.data$max.cort[index] <- ifelse(sample>1 &&
sample<5,
raw.saliva.data$cortisol[index], NA)
*************
and I get this error: Error in sample > 1 :
comparison (6) is possible only for atomic and list types
I can't figure out how to fix this problem. Any advice is appreciated.
Thank you.
--
*Melissa*
[[alternative HTML version deleted]]
Hello, 'sample' is a really bad name for a variable, it's already taken, it's an R function. sample>1 && sample<5 # '&&' is not vectorized, it's '&' you want. # Without 'ifelse' raw.saliva.data$max.cort[index] <- raw.saliva.data$cortisol[index & sample> 1 & sample < 5]Negate this last conjunction if you want to set the other 'max.cort' to NA, !(index & sample > 1 & sample < 5) And, finally, this is untested. Give a small dataset example, including 'sample' (after calling it something else). Hope this helps, Rui Barradas la mer wrote> > Hello, > > I apologize in advance for not providing sample data, I'm a very new to R > and can't easily generate appropriate sample data quickly. I'm hoping > someone can offer advice without it. > > This code below works and does what I want it to do, which is for a given > row in my dataframe, where the variable "peak.cort" = max, it makes the > value of another variable "max.cort" = to match the value of a third > variable "cortisol" for that row. > > ************* > index <- raw.saliva.data$peak.cort == 'max' > raw.saliva.data$max.cort[index] <- > (raw.saliva.data$cortisol[index]) > ************* > > Now, I want to execute this function only if the value of a fourth > variable, "sample" is >1 and <5. I tried to add an ifelse statement to the > code above so that it looks like this: > > ************* > index <- raw.saliva.data$peak.cort == 'max' > raw.saliva.data$max.cort[index] <- ifelse(sample>1 && > sample<5, > raw.saliva.data$cortisol[index], NA) > ************* > > and I get this error: Error in sample > 1 : > comparison (6) is possible only for atomic and list types > > I can't figure out how to fix this problem. Any advice is appreciated. > > Thank you. > -- > *Melissa* > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@ 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. >-- View this message in context: http://r.789695.n4.nabble.com/trouble-with-ifelse-statement-tp4630309p4630316.html Sent from the R help mailing list archive at Nabble.com.
It seems like your problem is that R can't find your variable "sample" and is instead finding its own sample() function which can't be compared to an integer and is giving your problem. It seems likely that sample is part of raw.saliva.data? If that's the case, change sample --> raw.saliva.data$sample However, I'm thinking that this isn't going to do quite what you really want because sample is long (corresponding to all the rows, not just the subset by index) -- you could probably do something like this instead: raw.saliva.data <- within(raw.saliva.data, max.cort[index] <- ifelse( (sample > 1 && sample < 5)[index], cortisol[index], NA)) Since you're telling R to look within() raw.saliva.data, lookup should probably work for you. Note that we have to restrict both the (sample) and (cortisol) parts of ifelse() to just the rows "index" for this to work (else things get lined up wrong) Note finally that you also have to reassign back to raw.saliva.data for this to have an effect. Hope this helps, Michael On Wed, May 16, 2012 at 5:01 PM, Melissa Rosenkranz <melissarosenkranz at gmail.com> wrote:> Hello, > > I apologize in advance for not providing sample data, I'm a very new to R > and can't easily generate appropriate sample data quickly. I'm hoping > someone can offer advice without it. > > This code below works and does what I want it to do, which is for a given > row in my dataframe, where the variable "peak.cort" = max, it makes the > value of another variable "max.cort" = to match the value of a third > variable "cortisol" for that row. > > ************* > index <- raw.saliva.data$peak.cort == 'max' > ? ? ? ? ? ?raw.saliva.data$max.cort[index] <- > (raw.saliva.data$cortisol[index]) > ************* > > Now, I want to execute this function only if the value of a fourth > variable, "sample" is >1 and <5. I tried to add an ifelse statement to the > code above so that it looks like this: > > ************* > index <- raw.saliva.data$peak.cort == 'max' > ? ? ? ? ? ?raw.saliva.data$max.cort[index] <- ifelse(sample>1 && sample<5, > raw.saliva.data$cortisol[index], NA) > ************* > > and I get this error: Error in sample > 1 : > ?comparison (6) is possible only for atomic and list types > > I can't figure out how to fix this problem. Any advice is appreciated. > > Thank you. > -- > *Melissa* > > ? ? ? ?[[alternative HTML version deleted]] > > ______________________________________________ > R-help at 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.