How to index tuple properly

Question

I have to form a Jacobi matrix with the following code. The rows of Jacobi are values of function residual.residual. and with each outer loop, the columns are added to Jacobi. Problem is I do not know how to use the index on variable 'Rop'.

I used the given index in matlab and it works fine there. but I guess I need to change it for python.

    for i1 in range(1,nxt-1):
    for j1 in range(1,nyt-1):
    Rop=();Rsp=();Rsgp=()
    pit[i1,j1]=pit[i1,j1]+ep;
    sit[i1,j1]=sit[i1,j1]+es;
    sgit[i1,j1]=sgit[i1,j1]+es;
    for i in range(1,nxt-1):#inner loop to calculate perturbed residual
         for j in range(1,nyt-1):
            if (index[i,j]!=0):

             rop,rwp,rgp=residual.residual(pit,sw,sg,i,j,boold,bwold,bgold,
                                    swold,sgold,rsoold,rswold,index, 
                                    delx, dely, depth, phi, kx, ky, 
                                    ax, ay, h, delt, qo, nxt, nyt, welin, 
                                    Vb, pvtgas, pvtoil, pvtw, relpermgo, 
                                    relpermow, time, it,fmult)
               Rop[count:count+2,col]+=(rop/ep,rwp/ep,rgp/ep)

            rop,rwp,rgp=residual.residual(po,sit,sg,i,j,boold,bwold,bgold,
                                    swold,sgold,rsoold,rswold,index, 
                                    delx, dely, depth, phi, kx, ky, 
                                    ax, ay, h, delt, qo, nxt, nyt, welin, 
                                    Vb, pvtgas, pvtoil, pvtw, relpermgo, 
                                    relpermow, time, it,fmult)
               Rop[count:count+2,col+1]+=(rop/es,rwp/es,rgp/es)

             rop,rwp,rgp=residual.residual(po,sw,sgit,i,j,boold,bwold,bgold,
                                    swold,sgold,rsoold,rswold,index, 
                                    delx, dely, depth, phi, kx, ky, 
                                    ax, ay, h, delt, qo, nxt, nyt, welin, 
                                    Vb, pvtgas, pvtoil, pvtw, relpermgo, 
                                    relpermow, time, it,fmult)
               Rop[count:count+2,col+2]+=(rop/es,rwp/es,rgp/es)

Answer 1

MATLAB uses 1-based indexing, while Python uses 0-based indexing.

Try changing all your ranges from the form range(1,nxt-1) to range(nxt) , which will give you a sequence from 0 to nxt-1 , inclusive. The long form is range(0, nxt) .

It's hard to tell where you want to stop based on your code, but if you want to stop before nxt-1 just adjust the last argument of range accordingly.

I'm not sure how to advise you on Rop[count:count+2,col] , since you haven't shown how count is defined.