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rdataframevectormultiplication

Running into error coercing data.frame to numerical values


I have a data.frame titled "matched_SNPs" here:

  SNP               ACB               ASW               BEB          EFF
rs10007883 0.536458333333333 0.549180327868853 0.191860465116279    -0.005748
rs10009522 0.604166666666667 0.475409836065574 0.162790697674419     0.008854
rs10010325 0.458333333333333 0.467213114754098 0.453488372093023    -0.006217
rs10010809             0.375 0.401639344262295 0.290697674418605     0.005879
rs10015151 0.572916666666667 0.442622950819672 0.546511627906977    -0.005789
rs10016978            0.5625 0.565573770491803 0.424418604651163    -0.005444

I wanted to make a new dataframe that is based off the values of columns 2, 3, and 4, multiplied by column 5, that is formatted like this:

ACB   ASW   BEB
value value value
value value value
value value value
value value value

I have tried new_df=(as.numeric(as.character(matched_SNPs[,2:4]))*as.numeric(as.character(matched_SNPs$EFF)))

but all I get is: Warning messages:
1: NAs introduced by coercion 
2: In as.numeric(as.character(matched_SNPs[, 2:4])) * as.numeric(as.character(matched_SNPs$EFF)) :
  longer object length is not a multiple of shorter object length

I have also tried the more basic weighted_freqs=(matched_SNPs[,2:27])*(matched_SNPs$EFF), but I get a warning message that says that In Ops.factor(left, right) : '*' not meaningful for factors.

How can I fix this?


Solution

  • We can simply do the multiplication

    matched_SNPs[2:4] * matched_SNPs[,5]
    #      ACB          ASW          BEB
    #1 -0.003083562 -0.003156689 -0.001102814
    #2  0.005349292  0.004209279  0.001441349
    #3 -0.002849458 -0.002904664 -0.002819337
    #4  0.002204625  0.002361238  0.001709012
    #5 -0.003316615 -0.002562344 -0.003163756
    #6 -0.003062250 -0.003078984 -0.002310535
    

    assuming that the columns are numeric

    If it is not numeric and is factor then convert the columns of interest to numeric first and then do the multiplication

    matched_SNPs[2:5] <- lapply(matched_SNPs[2:5], function(x) as.numeric(as.character(x)))