/*
 *  ==========================================================================
 *  Compute internal forces and reactions in cantilever truss structure.
 *  
 *  Matrices : spTruss   = Represents truss geometry and element connectivity.
 *           : spLoad    = External forces acting on the truss nodes.
 *           : spForce   = Internal member forces acting in truss elements.
 *           : spSupport = Relationship between truss and support reactions
 *           : spSupport = Matrix of support reaction forces.
 *  ==========================================================================
 *  Copyright (C) 1996 by Mark Austin and David Mazzoni.
 *                                                                     
 *  This software is provided "as is" without express or implied warranty.
 *  Permission is granted to use this software on any computer system,
 *  and to redistribute it freely, subject to the following restrictions:
 * 
 *  1. The authors are not responsible for the consequences of use of
 *     this software, even if they arise from defects in the software.
 *  2. The origin of this software must not be misrepresented, either
 *     by explicit claim or by omission.
 *  3. Altered versions must be plainly marked as such, and must not
 *     be misrepresented as being the original software.
 *  4. This notice is to remain intact.
 *  
 *  Written By: Mark Austin                                          July 1996
 *  ==========================================================================
 */

#include <stdio.h>
#include <math.h>
#include "matrix.h"
#include "miscellaneous.h"

int main( void ) {
MATRIX *spTruss, *spLoad, *spForce, *spSupport, *spReactions;
enum { NoElmts = 6, NoReactions = 4 };
int ii, ij;

    /* [a] : Setup matrix for "truss connectivity" */

    spTruss = matAllocIndirect( "Truss Connectivity", DoubleArray, NoElmts, NoElmts );

    spTruss->uMatrix.dpp[ 0 ][ 0 ] =   1;
    spTruss->uMatrix.dpp[ 0 ][ 1 ] =  -1;

    spTruss->uMatrix.dpp[ 1 ][ 3 ] =   1;

    spTruss->uMatrix.dpp[ 2 ][ 1 ] =   1;
    spTruss->uMatrix.dpp[ 2 ][ 2 ] =   1/sqrt(2);

    spTruss->uMatrix.dpp[ 3 ][ 2 ] =   1/sqrt(2);

    spTruss->uMatrix.dpp[ 4 ][ 2 ] =   1/sqrt(2);
    spTruss->uMatrix.dpp[ 4 ][ 4 ] =  -1/sqrt(2);
    spTruss->uMatrix.dpp[ 4 ][ 5 ] =  -1;

    spTruss->uMatrix.dpp[ 5 ][ 2 ] =   1/sqrt(2);
    spTruss->uMatrix.dpp[ 5 ][ 3 ] =   1;
    spTruss->uMatrix.dpp[ 5 ][ 4 ] =   1/sqrt(2);

    /* [b] : Setup matrix for "external loads" on truss nodes */

    spLoad = matAllocIndirect( "External Loads", DoubleArray, NoElmts, 1);

    spLoad->uMatrix.dpp[ 1 ][ 0 ] =  10;
    spLoad->uMatrix.dpp[ 3 ][ 0 ] =  10;

    /* [c] : Print matrices for "truss connectivity" and "external loads" */

    matPrint( spTruss );
    matPrint( spLoad );

    /* [d] : Solve equations and print "internal member" forces */

    spForce = matSolve( spTruss, spLoad );
    spForce->cpName = saveString( "Member Forces", __FILE__, __LINE__ );

    matPrint( spForce );

    /* [e] : Setup matrix for "support reactions" */

    spSupport = matAllocIndirect( "Truss/Support Reactions Connectivity",
                                   DoubleArray, NoReactions, NoElmts );

    spSupport->uMatrix.dpp[ 0 ][ 0 ] =  -1;
    spSupport->uMatrix.dpp[ 0 ][ 4 ] =  -1/sqrt(2);
    spSupport->uMatrix.dpp[ 1 ][ 4 ] =  -1/sqrt(2);
    spSupport->uMatrix.dpp[ 2 ][ 5 ] =  -1;

    /* [f] : Compute and print "support reactions" */

    spReactions = matMult( spSupport, spForce );
    spReactions->cpName = saveString( "Support Reactions", __FILE__, __LINE__ );

    matPrint( spReactions );

    /* [g] : Clean up */

    matFree( spTruss );
    matFree( spLoad );
    matFree( spForce );
    matFree( spSupport );
    matFree( spReactions );

}