[R] How to multiply all dataframe rows by another dataframe's columns

[Anders Nielsen]

  matrix(Y[,2]%o%X[,2],ncol=1)


On Wednesday 29 August 2007 03:21 pm, Luke Neraas wrote:
> Hello,
> 
> I have two data frames, X and Y, with two columns each and different numbers
> of rows.
> 
> # creation of data frame X
> 
> Loc1.alleles     <- c(1,5,6,7,8)
> Loc1.Freq        <- c(0.35, 0.15, 0.05, 0.10, 0.35)
> Loc1             <- cbind( Loc1.alleles,Loc1.Freq)
> X            <- data.frame(Loc1)
> 
> #creation of data frame Y
> 
> Loc2.alleles  <- c(1,4,6,8)
> Loc2.Freq     <- c(0.35, 0.35, 0.10, 0.20)
> Loc2          <- cbind(Loc2.alleles, Loc2.Freq)
> Y             <- data.frame (Loc2)
> 
> I would like a flexible way to multiply each element of second column of the
> X data frame
> by each element of the second column of the Y data frame.
> 
>  example of what the operation need to do:  X[1,2]*Y[,2] ;
> X[2,2]*Y[,2].............X[4,2]*Y[,2]
> 
> I have worked on a variety of "for" loops to get this to work without
> success.
> 
> The final result should look like a column like this
> 
>     "all_X[,2] * all_Y[,2]"
>         0.1225
>         0.1225
>         0.0350
>         0.0700
>         0.0525
>         0.0525
>         0.0150
>         0.0300
>         0.0175
>         0.0175
>         0.0050
>         0.0100
>         0.0350
>         0.0100
>         0.0200
>         0.1225
>         0.1225
>         0.0350
>         0.0700
> 
> any help would be greatly appreciated
> 
> Luke Neraas
> 
> lukasneraas at gmail.com
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>