Returns a diagonal-i matrix
A = makematrix_diagonali ( n )
a 1-by-1 matrix of doubles, integer value, the size of the matrix to return
a n-by-n matrix of doubles, the Diagonal-i matrix
Returns a matrix of size n with i on the diagonal.
For i=1,2,...,n, we have :
A(i,i) = i
J.C. Nash, Compact Numerical Methods for Computers: Linear Algebra and Function Minimisation, second edition, Adam Hilger, Bristol, 1990 (Appendix 1).