[R] building transformation macro

[David Winsemius]

On May 24, 2012, at 9:06 AM, David Winsemius wrote:

>
> On May 24, 2012, at 4:43 AM, davv.vikas wrote:
>
>> Hi All,
>>
>> I am writing a macro which perform following functionality
>> 1) take a file say excel or csv
>> 2)read all the labels
>> 3) dynamically genrate square,square-root,log  of each column with
>> appropiate column name and write it to a new file,
>>
>> i am stuck at dynamically genrateing the column names like  
>> Revenue_square
>> etc.
>>
>> Exmaple " i have a excel with 3 columns Revenue, cost & profit
>> Now my Macro should be able to  read the values and for each coulmn  
>> and
>> perform square,square root and log of   Revenue, cost & profit and  
>> write to
>> excel with column names as Revenue_square,Revenue_squareroot,  
>> Revenue_log
>> cost_square etc...
>>
>> Below is my code
>>
>> test$Rev_square = test[c(1)]^2
>>
> I would use test[[1]]^2. Generally one wants to pull the vector out  
> of the list "container".
>>
>> data=read.delim2("//ARLMSAN01/CTRX_Data/vikasK.sharma/Desktop/ 
>> balancesheet_example.csv",header=T,sep=",")
>>
>> headings = names(data)
>> show (headings)
>> HEADINGS = toupper(headings)
>> # Perhaps replacing your for-loop body with this
> for ( i in 1:length(HEADINGS))
>> {
>>
> assign(paste(HEADINGS[i],  "Rev_Sqr", sep=""), data[[i]]^2)
>>
>> }
>
> The generalization to additional transformations seems obvious.

The solution offered in StackOverflow by Greg Snow is better.

AND please stop cross-posting. It is not specifically deprecated on  
SO, but it is on Rhelp.

-- 

David Winsemius, MD
West Hartford, CT