Dear R users, Suppose I have 2 parts of a dataframe, say ABCD 2143 3245 2154 (the real dataframe is 160 columns with each 120 rows) and I want to multiply every element in [,A:B] with every element in [,C:D]; What is the most elegant way to do this? I??ve been thinking of converting [,A:B] to a matrix, and then multiplying it with the inverse of [,C:D]; would that be correct? The result should look like E;F 8;3 12;10 10;4 Thanks very much for any suggestions Christoph
dataframe (matrix) multiplication
2 messages · Christoph Scherber, Peter Wolf
where is the problem? input: A<-c(2,3,2); B<-c(1,2,1); C<-c(4,4,5); D<-c(3,5,4) df<-data.frame(A,B,C,D) c1<-1:2; c2<-3:4 df[,c1]*df[,c2] output: A B 1 8 3 2 12 10 3 10 4 Peter Wolf
Christoph Scherber wrote:
Dear R users, Suppose I have 2 parts of a dataframe, say ABCD 2143 3245 2154 (the real dataframe is 160 columns with each 120 rows) and I want to multiply every element in [,A:B] with every element in [,C:D]; What is the most elegant way to do this? I??ve been thinking of converting [,A:B] to a matrix, and then multiplying it with the inverse of [,C:D]; would that be correct? The result should look like E;F 8;3 12;10 10;4 Thanks very much for any suggestions Christoph
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