[R] For applying formula in rows

[Joshua Wiley]

Hi Vikas,

Here is one way:

df <- read.table("summary.txt", header = TRUE)
str(df)
df[, "total"] <- rowSums(df[, 3:6])
df[, 3:6] <- apply(df[, 3:6], 2, function(x) x / df[, "total"] * df[,
"new"] * 2)

> head(df)
  V1        V2 CaseA CaseC CaseG CaseT new total
1 10 135344109     0     0    24     0  12     1
2 10 135344110     0    24     0     0  12     1
3 10 135344111     0     0    24     0  12     1
4 10 135344112     0     0    24     0  12     1
5 10 135344113     0     0    24     0  12     1
6 10 135344114    24     0     0     0  12     1

Note that I read the data in differently than you did.  This matters.

Cheers,

Josh

2011/7/12 Bansal, Vikas <vikas.bansal at kcl.ac.uk>:
> Dear all,
>
> I have a problem and it is very difficult for me to get a code.
> I am reading a file(attached with this mail) using the code-
>
>  df=read.table("summary.txt",fill=T,sep="",colClasses = "character",header=T)
> and dataframe df is like this-
>
> V1        V2      CaseA CaseC CaseG CaseT new
>  10 135344109     0     0             1     0        12
>  10 135344110     0     1             0     0         12
>  10 135344111     0     0             1     0         12
>  10 135344112     0     0             1     0          12
>  10 135344113     0     0             1     0          12
>  10 135344114     1     0             0     0          12
>  10 135344115     1     0             0     0           12
>  10 135344116     0     0             0     1           12
>  10 135344117     0     1             0     0           12
>  10 135344118     0     0             0     1            12
>
> I want to apply a formula which is  (number/total)*new*2.
> where number is in column caseA,G,C,T and total is sum of these 4 columns.I will explain with an example.the output of first row should be-
>
> V1        V2      CaseA CaseC CaseG CaseT new
>  10 135344109     0     0             24     0        12
>
> because sum of 3rd,4th,5th and 6th column is 1 for first row.and for case A,C and T if we will apply above formula the answer will be zero (0/1)*12*2 which is equal to 0 but for Case G-
> (1/1)*12*2 which is equal to 24.
>
>
> Can you please help me.
>
>
>
>
>
> Thanking you,
> Warm Regards
> Vikas Bansal
> Msc Bioinformatics
> Kings College London
> ______________________________________________
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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.
>
>



-- 
Joshua Wiley
Ph.D. Student, Health Psychology
University of California, Los Angeles
https://joshuawiley.com/