Hello. I am trying to use dtrnlsp_solve function, but I do not know the format of fjac. I calculate fjac myself. According to the manual, it is a 1D array of size m*n where m is the number of function values and n is the number of variables. But, the manual does not say how the fjack elements are arranged. There are two possible ways:

for(i=0;i

or

for(j=0;j

Which one is correct?