[R] assignment of matrix

[Uwe Ligges]

Îâ ê» wrote:

> Hi,
> I have created a matrix and initially all elements in the matrix was 
> assigned to NA.Then I want to assign values to some elements of this 
> matrix. Can I use formation like matrix[i][j] <- 4?if not, how can i do 
> this? now I have three vectors
> y1  y2   y3
> 3   4     3.1
> 5   2     4.2
> if I want to assign y3's value to matrix, where the value's row and 
> column should correspond the y1's and y2's value, such like
> matrix[y1[1]][y2[1]] <- y3[1]

For a matrix X:

 X[cbind(y1, y2)] <- y3

Uwe Ligges



> how can this be realized?
> thanks
> Hao Wu
> 
> 
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