On Jul 7, 12:21 pm, Umrao <umraoa...@gmail.com> wrote: > If I have an identity matrix say of order 4 > a=[1 0 0 0 > 0 1 0 0 > 0 0 1 0 > 0 0 0 1] > > Now i want to generate a new matrix of oder 6*4 using this as > co1=a[1,]-a[2,]; > co2=a[1,]-a[3,]; > co3=a[1,]-a[4,]; > co4=a[2,]-a[3,]; > co5=a[2,]-a[4,]; > co6=a[3,]-a[4,]; > co=co1//co2//co3//co4//co5//co6; > this output is like as under > co=[1 -1 0 0 > 1 0 -1 0 > 1 0 0 -1 > 0 1 -1 0 > 0 1 0 -1 > 0 0 1 -1] > > I whant to generate this for any order of identity matrix. > I am not able to run this in loop so please help me to solve this > problem. > > regards, > amit

Hi, Here is solution, maybe not very beautiful, but working;

proc iml; ord = {4}; a = i(ord); dim = comb(ord,2); co = j(dim,ord,0); k = 1; do i = 1 to (ord-1); do j = (i+1) to ord; co[k, ] = a[i, ] - a[j, ]; k = k+1; end; end; quit;

Best, Alexandra