Matlab file input - algorithm

Question

I am asking this as a person with no experience in Matlab.
The project is simple; write a code to analyse a simple truss. The following is what a team mate has been working on - I'm supposed to write the input file:
file = input('File Input): ', 's');
run(file)
%Cc corresponds to # of joints and Rc corresponds to # of members
[Rc Cc] = size(C);
%JM is a matrix that contains the joint numbers that each member is
%connected to. The row number is the member number
JM = zeros(Cc, 2);
%x components
Ax = zeros(Rc, Cc);
%y components
Ay = zeros(Rc, Cc);
My_total_length = 0;
Member_length = 0;
%finding JM matrix which stores the joints that each member is connected to
%loop through C matrix and store the joint number each member is connected
%to
for j = 1:Cc
counter = 0;
for i = 1:Rc
if C(i,j) == 1
counter = counter + 1;
JM(j, counter) = i;
end
end
end
%using JM, loop through C again and create the equilibrium equations using
%the locations of each joint X and Y
for j = 1:Cc
counter = 3;
for i = 1:Rc
if C(i,j) == 1
%use counter to get x2 - x1 from JM vector
counter = counter - 1;
%find x and y distance of member and divide it by length of the member
Member_length = sqrt(((X(JM(j,2))) - ...
(X(JM(j,1))))^2 + ((Y(JM(j,2))) - (Y(JM(j,1))))^2);
Ax(i,j) = (X(JM(j,counter)) - X(i)) / Member_length; ! 13!
Ay(i,j)= (Y(JM(j, counter)) - Y(i)) / Member_length;
end
end
My_total_length = My_total_length + Member_length;
end
%combine the 4 matrices to create the larger matrix A
A = [Ax Sx; Ay Sy];
%define the vector for the forces on each member
T = zeros(Cc +3, 1);
T = inv(A)*-L;
%OUTPUT
%Find what the load on the truss is by looping through the weight vector and finding the load
for i=1:length(L)
if L(i) ~= 0
Load = L(i);
end
end
%Display load
fprintf('Load: %f N \n',Load)
%Display the forces on the members. Loop through Vector T up to the where reaction forces are
fprintf('Member forces in Newtons: \n')
for i = 1:length(T)-3
if (T(i)<0)
fprintf('m%d: %2.3f (C) \n', i, abs(T(i)))
elseif (T(i)==0)
fprintf('m%d: %d \n', i, abs(T(i)))
else
fprintf('m%d: %2.3f (T) \n', i, abs(T(i)))
end
end
%Display the last three items of vector T, the reaction forces
fprintf('Reaction forces in Newtons: \nSx1: %2.3f \nSy1: %2.3f \nSy2: %2.3f \n'...
, T(length(T)-2), T(length(T)-1), T(end))
%Calculate cost of truss
Cost = Rc*(10) + My_total_length*(1);
%Display the cost of truss
fprintf('Cost of truss: $%3.2f \n', Cost)
%Display load/cost ratio
fprintf('Theoretical max load/cost ratio in N/$: %2.4f \n', (Load/Cost))
Now, the problem I have is actually the input file. What kind of file should I save it as? How do I write it in the file? When I'm trying to run the code and need to access the file, how do I write the file name (with .txt after)? Some of the information that has to go into the file is below:
Sx = [ 1 0 0; 0 0 0; 0 0 0; 0 0 0; 0 0 0; 0 0 0; 0 0 0; 0 0 0; 0 0 0, 0 0 0; 0 0 0]
Sy = [ 0 1 0; 0 0 0; 0 0 0; 0 0 0; 0 0 0; 0 0 0; 0 0 0; 0 0 0; 0 0 0; 0 0 0; 0 0 1]
C = [ 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0; 1 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ; 0 1 1 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0; 0 0 0 1 1 0 1 1 0 0 0 0 0 0 0 0 0 0 0; 0 0 0 0 0 1 1 0 1 1 0 0 0 0 0 0 0 0 0; 0 0 0 0 0 0 0 1 1 0 1 1 0 0 0 0 0 0 0; 0 0 0 0 0 0 0 0 0 1 1 0 1 1 0 0 0 0 0; 0 0 0 0 0 0 0 0 0 0 0 1 1 0 1 1 0 0 0; 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 1 1 0; 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 1; 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1]
L = [ 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 500; 0; 0; 0; 0; 0]
X = [ 0,6,12,18,24,30,36,42,48,54,60]
Y = [ 0,8,0,8,0,8,0,8,0,8,0]
Would truly appreciate any help.

Answer 1

You can use fwrite to write to a txt file. This does however need fread and so code to read it into matlab again. xlswrite and xlsread does the same for xls files.
However, the simplest way if a file only is to be used together with matlab is to use the functions load and save. You can read the help for them with help save or help load, but the can save one or more variables to a .mat file.
a = 1;
b = 'e';
c = [1,2;3,4];
d = struct('hi',1,'you','e');
save('myFileName.mat','a','b','c','d');
clear;
load('myFileName.mat')
You can also write filepath/filename (or \ for windows) where filepath is the full path.