Hi!

I need to conditionally update a dataframe field based on values in  
other fields and can't find even how to search for this right. Sorry  
if this has been asked before.

But, specifically, I have a 490 X 221 dataframe and need to count, by  
row, how many fields in Dataframe$field_a...Dataframe$field_zz are  
non-null and enter this value in Dataset$ABCtaskNum. I have field  
name definitions in a vector "vars" and tried writing a custom  
function to handle the within-row calculation

myfunct <-function () {for (i in 1:length(vars)) {if (vars[i] != NA)  
{Dataset$ABCtaskNum<-Dataset$ABCtaskNum+1}}}

and then use "apply" to handle the row to row calculation

Dataset <- apply(Dataset, 1, myfunc) Where Dataset already has field  
Dataset$ABCtaskNum set to 0 in all rows.

But that didn't work. Doesn't help if I declare variables (vars and  
ABCtaskNum) in the function declaration either, but then I haven't  
quite figured out how best to do variable substitutions in R.

Thanks for any help. Cheers

Jon

Soli Deo Gloria

Jon Erik Ween, MD, MS
Scientist, Kunin-Lunenfeld Applied Research Unit
Director, Stroke Clinic, Brain Health Clinic
     Baycrest Centre for Geriatric Care
Assistant Professor, Dept. of Medicine, Div. of Neurology
     University of Toronto Faculty of Medicine

Posluns Building, 6th Floor, Room 644
Baycrest Centre for Geriatric Care
3560 Bathurst Street
Toronto, Ontario M6A 2E1
Canada

Phone: 416-785-2500 x3636
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Email: [EMAIL PROTECTED]


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