CODEWITHSUNDEEP
r
user3354212
user3354212

Reputation: 1112

how to extract out corresponding values from another dataframe in r

I have two data frames: 

    d1=read.table(text="X1   X2   X3   X4   X5
    1212 1213 1214 1216 1215
    1194 1195 1193 1212 1190
    1555 1554 1553 1556 1557
    1212 1213 1214 1216 1215
    1194 1195 1193 1212 1190
    1212 1213 1214 1216 1215
     904 1321 1322 1323 1324
    1212 1213 1214 1216 1215
    1206 1207 1208 1209 1210
    1206 1207 1208 1209 1210", header=T, stringsAsFactors=F)

       d2=read.table(text="X1    X2    X3    X4    X5    LG  
    Chr11 Chr11 Chr11 Chr11 Chr11 Chr11  
    Chr11 Chr11 Chr11 Chr11 Chr11 Chr11  
    Chr14 Chr12 Chr15 Chr10 Chr15 Chr15  
    Chr11 Chr11 Chr11 Chr11 Chr11 Chr11  
    Chr11 Chr11 Chr11 Chr11 Chr11 Chr11  
    Chr11 Chr11 Chr11 Chr11 Chr11 Chr11  
    Chr08 Chr12 Chr12 Chr12 Chr12 Chr12
    Chr11 Chr11 Chr11 Chr11 Chr11 Chr11  
    Chr11 Chr11 Chr11 Chr11 Chr11 Chr11  
    Chr11 Chr11 Chr11 Chr11 Chr11 Chr11", header=T, stringsAsFactors=F)

I would like to extract value from d1 based on the evaluation: if the d2$LG equals to values from column X1 to X5. extract the values in d1 where the corresponding position in d2 is the first position having the same value as d2$LG. The extracted values is the column "PO". The expected result as below:

       X1    X2    X3    X4    X5    LG PO
    Chr11 Chr11 Chr11 Chr11 Chr11 Chr11 1212
    Chr11 Chr11 Chr11 Chr11 Chr11 Chr11 1194
    Chr14 Chr12 Chr15 Chr10 Chr15 Chr15 1553
    Chr11 Chr11 Chr11 Chr11 Chr11 Chr11 1212
    Chr11 Chr11 Chr11 Chr11 Chr11 Chr11 1194
    Chr11 Chr11 Chr11 Chr11 Chr11 Chr11 1212
    Chr08 Chr12 Chr12 Chr12 Chr12 Chr12 1321
    Chr11 Chr11 Chr11 Chr11 Chr11 Chr11 1212
    Chr11 Chr11 Chr11 Chr11 Chr11 Chr11 1206
    Chr11 Chr11 Chr11 Chr11 Chr11 Chr11 1206

Thank you for any helps.

Upvotes: 1

Views: 25

Answers (1)

akrun
akrun

Reputation: 887118

We can use row/column indexing for this. Create the column index by comparing the first 5 columns ('X1' to 'X5') with 'LG' column of 'd2', get the column index of the first match for each row with max.col, cbind with the row index (seq_len(nrow(d2))) and use that to extract the values that corresponds to 'd1' (assuming both 'd1' and 'd2' - have the same dimensions)

d2$PO <- d1[cbind(seq_len(nrow(d2)), max.col(d2[1:5] == d2$LG, 'first'))]
d2$PO
#[1] 1212 1194 1553 1212 1194 1212 1321 1212 1206 1206

Upvotes: 2

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