[R] Multiplying elements of vectors

[Mariana Martinez-Morales]

Hi guys:

Sorry if this question is very basic. I’m learning basic matrix and
vectors multiplication to develop a population matrix model for
plants. I’m trying to multiply the elements of two vectors (each of
the “x” values by each of the “y” values) to obtain a square matrix of
xy values.

f.e.
x<-seq(5,205)
y<-seq(5,20,5)
stages<-c(“Sdl”, “Juv”, “Ad1”, “Ad2”)

If I just multiply xy as a matrix
xy<-matrix(x,y,nrow=4,ncol=4,dimnames=list(stages,stages))

I obtain this

xy
        Sdl Juv A1 A2
Sdl   5  10 15 20
Juv   5  10 15 20
A1    5  10 15 20
A2    5  10 15 20

but what I want to obtain is this matrix

        Sdl    Juv     A1    A2
Sdl   25    50      75     100
Juv   50    100    150   200
A1    75    50      225   300
A2    100  200    300   400