Hello everyone,
I'm having a problem with a function that I wrote that is supposed to add a
row to dataframe based upon a conditional statement. To explain I've used
an example below:
#create data frame
animals=c("bird","dog","cat")
animals=rep(animals,each=4)
animals=animals[1:11]
animalYears=c(1,1,2,2,1,1,2,2,1,1,2)
animalMass=round(runif(11,min=10,max=50),0)
comAn=as.data.frame(cbind(animals,animalYears,animalMass))
comAn
* animals* *animalYears* *animalMass*
1 bird 1 30
2 bird 1 32
3 bird 2 27
4 bird 2 16
5 dog 1 22
6 dog 1 25
7 dog 2 41
8 dog 2 22
9 cat 1 30
10 cat 1 37
11 cat 2 49
We can see here that for every type of animal I have two years of mass
measurements, except for the cat in year 2. What I want to do is add an
additional row to the end of the dataframe that consists strictly of NAs
and then I can substitute those out later.
So what I first did was split the 'comAn' dataframe into the different
Animal by Year combos.
#This line splits 'com_An' into a list ordered by the Animal by Year combos
comAn_split=split(comAn, paste(comAn$animals,comAn$animalYear))
Then I wrote the function that identifies whether a particular Animal by
Year combo is less than two rows in length and if so it should add another
row that consists only of NAs using the vector 'NAs':
#This function identifies the length of each Animal by Year combo and then
#uses the rbind function built in R to add a row
#to each animal by year combo if they have less than 2 samples
addNA <- function(comAn) {
NAs=c(NA,NA,NA)
ind <- seq_len(nrow(comAn))
comAn[ifelse(length(ind)<2,rbind(NAs),length(ind)),]
}
#This applies the function addNs to the animals data organized in list
format
addedNAcomAn <- do.call(rbind, lapply(comAn_split, addNA))
addedNAcomAn
When I apply the function to the list of the different Animal by Year
combos this is what I get:
animals animalYears animalMass
bird 1 bird 1 23
bird 2 bird 2 50
cat 1 cat 1 15
cat 2 <NA> <NA> <NA>
dog 1 dog 1 23
dog 2 dog 2 38
What I expect is this:
animals animalYears animalMass
1 bird 1 41
2 bird 1 23
3 bird 2 23
4 bird 2 50
5 dog 1 49
6 dog 1 23
7 dog 2 13
8 dog 2 38
9 cat 1 42
10 cat 1 15
11 cat 2 33
12 NA NA NA
Am I conditioning improperly within the function or am I missing something
else. Any help would be greatly appreciated.
Best
--
Curtis Burkhalter
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