e272.m

matlab算法集 matlab算法集

%-----------------------------------------------------------------------
% Example 2.7.2: Planar Truss 
%-----------------------------------------------------------------------

% Initialize A 

   clc                            % clear screen
   clear                          % clear variables
   n = 8;			  % number of forces
   theta = pi/3;                  % joint angle A
   phi = pi/6;                    % joint angle D
   g = [0 0 -250 0 0 1500 0 0]';  % load forces
   A = zeros (n,n);

% Compute A

   fprintf ('Example 2.7.2: Planar Truss\n');
   A(1,1) = cos(theta);
   A(2,1) = sin(theta);
   A(3,1) = -cos(theta);
   A(4,1) = -sin(theta);
   A(3,4) = cos(phi);
   A(4,4) = -sin(phi);
   A(8,4) = sin(phi);
   A(7,4) = -cos(phi);
   A(1,2) = 1;  A(2,7) = 1;  A(5,5) = 1;  A(6,3) = 1; A(8,8) = 1;
   A(1,6) = -1; A(4,3) = -1; A(5,2) = -1; A(7,5) = -1;
   show ('A',A)
   show ('g',g)

% Find forces 

   show ('K(A)',condnum(A,0))
   f = gauss (A,g);
   show ('f',f)
   show ('||r(f)||',residual(A,g,f))
%-----------------------------------------------------------------------