FORTRAN 77 NEQNF IMSL Solver, 2 variables, 6 equations

Question

I am trying to use NEQNF to solve a system of 6 non linear equations. I need to determine 2 variables to solve my system. According to description i need to define "N" which is the length of "X"(variables) AND "F"(equations).

Does this mean that i can use this solver only if X=F? Because N is defindes as an integer in the example given below in the description.

Or can i define N as a vector? How does declaration of N supposed to look like in this case?

Answer 1

From the link you gave:

X – The point at which the functions are evaluated. (Input) X should not be changed by FCN.

F – The computed function values at the point X. (Output)

N — Length of X and F.

X and F are vectors of length N (scalar!). X is the input to FCN, and F the output. So I would guess that F is (generally) not equal to X.