I have a matrix, named "mat", and a smaller matrix, named "center".
temp = c(1.8421,5.6586,6.3526,2.904,3.232,4.6076,4.8,3.2909,4.6122,4.9399)
mat = matrix(temp, ncol=2)
[,1] [,2]
[1,] 1.8421 4.6076
[2,] 5.6586 4.8000
[3,] 6.3526 3.2909
[4,] 2.9040 4.6122
[5,] 3.2320 4.9399
center = matrix(c(3, 6, 3, 2), ncol=2)
[,1] [,2]
[1,] 3 3
[2,] 6 2
I need to compute the distance between each row of mat with every row of center. For example, the distance of mat[1,] and center[1,] can be computed as
diff = mat[1,]-center[1,]
t(diff)%*%diff
[,1]
[1,] 3.92511
Similarly, I can find the distance of mat[1,] and center[2,]
diff = mat[1,]-center[2,]
t(diff)%*%diff
[,1]
[1,] 24.08771
Repeat this process for each row of mat, I will end up with
[,1] [,2]
[1,] 3.925110 24.087710
[2,] 10.308154 7.956554
[3,] 11.324550 1.790750
[4,] 2.608405 16.408805
[5,] 3.817036 16.304836
I know how to implement it with for-loops. I was really hoping someone could tell me how to do it with some kind of an apply() function, maybe mapply() I guess.
Thanks