Fortran And MatLab

[jecstir2112]

Hey, so basically i need to be able to enter the dimensions of a matrix (nxn), take the inverse and, multiply it by another 1xn. I have written a Matlab equiv for this.

clc
Clear all
%% input variables
n = input('Input the number of nodes ')
W = input('Input the length of the slab(W)')

Sig_tr = 0.0362;
Sig_a = 0.1532;
vSig_f = 0.1570;
Rel_abs = 1;
S_o = 10^8;

Lambda_tr = 1/Sig_tr ;
D = Lambda_tr/3;
L = (D/Sig_a)^.5;


dx = W / (n-1);

k = S_o*L/(2*D);

%% matrix formation
%Slab Reactor
A = zeros(n,n);
B = zeros(n,1);

Y = zeros(n,n);
Z = zeros(n,1);

%matrix Parameter Values
Y(1,1) = ((D/dx)+(Sig_a*dx/2));
Y(1,2) = -D/dx;
Z(1,1) = S_o/2;

for icount = 2:n-1
Y(icount,icount) = (2*D)/dx+Sig_a*dx;
Y(icount,icount+1) = -D/dx;
Y(icount,icount-1) = -D/dx;
Z(icount,1) = 0;
end;

A= Y(1:n-1 , 1:n-1);
B = Z(1:n-1);


AAA = inv(A)*B;

% print this output
AAA = 0

 

[xwb]

You'll probably find that Fortran doesn't have built in matrix inversion. You can get the source for matrix inversion from sites like

http://www.dreamincode.net/code/snippet1272.htm

Fortran has a few matrix operations like assignment, addition, subtraction, dot products. I don't know whether the multiplication is matrix multiplication or element by element.

It is difficult to tell from the code, what is an array and what is not. Also difficult to tell what is an integer and what isn't. Can guess at some of them but not all of them.