Prev Next

@(@\newcommand{\W}[1]{ \; #1 \; } \newcommand{\R}[1]{ {\rm #1} } \newcommand{\B}[1]{ {\bf #1} } \newcommand{\D}[2]{ \frac{\partial #1}{\partial #2} } \newcommand{\DD}[3]{ \frac{\partial^2 #1}{\partial #2 \partial #3} } \newcommand{\Dpow}[2]{ \frac{\partial^{#1}}{\partial {#2}^{#1}} } \newcommand{\dpow}[2]{ \frac{ {\rm d}^{#1}}{{\rm d}\, {#2}^{#1}} }@)@
Old Matrix Multiply as a User Atomic Operation: Example and Test

Deprecated 2013-05-27
This example has been deprecated; use atomic_mat_mul.cpp instead.

Include File
This routine uses the include file old_mat_mul.hpp .
# include <cppad/cppad.hpp>
# include "old_mat_mul.hpp"

bool old_mat_mul(void)
{     bool ok = true;
     using CppAD::AD;

     // matrix sizes for this test
     size_t nr_result = 2;
     size_t n_middle  = 2;
     size_t nc_result = 2;

     // declare the AD<double> vectors ax and ay and X
     size_t n = nr_result * n_middle + n_middle * nc_result;
     size_t m = nr_result * nc_result;
     CppAD::vector< AD<double> > X(4), ax(n), ay(m);
     size_t i, j;
     for(j = 0; j < X.size(); j++)
          X[j] = (j + 1);

     // X is the vector of independent variables
     CppAD::Independent(X);
     // left matrix
     ax[0]  = X[0];  // left[0,0]   = x[0] = 1
     ax[1]  = X[1];  // left[0,1]   = x[1] = 2
     ax[2]  = 5.;    // left[1,0]   = 5
     ax[3]  = 6.;    // left[1,1]   = 6
     // right matrix
     ax[4]  = X[2];  // right[0,0]  = x[2] = 3
     ax[5]  = 7.;    // right[0,1]  = 7
     ax[6]  = X[3];  // right[1,0]  = x[3] = 4
     ax[7]  = 8.;    // right[1,1]  = 8
     /*
     [ x0 , x1 ] * [ x2 , 7 ] = [ x0*x2 + x1*x3 , x0*7 + x1*8 ]
     [ 5  , 6 ]    [ x3 , 8 ]   [ 5*x2  + 6*x3  , 5*7 + 6*8 ]
     */

     // The call back routines need to know the dimensions of the matrices.
     // Store information about the matrix multiply for this call to mat_mul.
     call_info info;
     info.nr_result = nr_result;
     info.n_middle  = n_middle;
     info.nc_result = nc_result;
     // info.vx gets set by forward during call to mat_mul below
     assert( info.vx.size() == 0 );
     size_t id      = info_.size();
     info_.push_back(info);

     // user defined AD<double> version of matrix multiply
     mat_mul(id, ax, ay);
     //----------------------------------------------------------------------
     // check AD<double>  results
     ok &= ay[0] == (1*3 + 2*4); ok &= Variable( ay[0] );
     ok &= ay[1] == (1*7 + 2*8); ok &= Variable( ay[1] );
     ok &= ay[2] == (5*3 + 6*4); ok &= Variable( ay[2] );
     ok &= ay[3] == (5*7 + 6*8); ok &= Parameter( ay[3] );
     //----------------------------------------------------------------------
     // use mat_mul to define a function g : X -> ay
     CppAD::ADFun<double> G;
     G.Dependent(X, ay);
     // g(x) = [ x0*x2 + x1*x3 , x0*7 + x1*8 , 5*x2  + 6*x3  , 5*7 + 6*8 ]^T
     //----------------------------------------------------------------------
     // Test zero order forward mode evaluation of g(x)
     CppAD::vector<double> x( X.size() ), y(m);
     for(j = 0; j <  X.size() ; j++)
          x[j] = double(j + 2);
     y = G.Forward(0, x);
     ok &= y[0] == x[0] * x[2] + x[1] * x[3];
     ok &= y[1] == x[0] * 7.   + x[1] * 8.;
     ok &= y[2] == 5. * x[2]   + 6. * x[3];
     ok &= y[3] == 5. * 7.     + 6. * 8.;

     //----------------------------------------------------------------------
     // Test first order forward mode evaluation of g'(x) * [1, 2, 3, 4]^T
     // g'(x) = [ x2, x3, x0, x1 ]
     //         [ 7 ,  8,  0, 0  ]
     //         [ 0 ,  0,  5, 6  ]
     //         [ 0 ,  0,  0, 0  ]
     CppAD::vector<double> dx( X.size() ), dy(m);
     for(j = 0; j <  X.size() ; j++)
          dx[j] = double(j + 1);
     dy = G.Forward(1, dx);
     ok &= dy[0] == 1. * x[2] + 2. * x[3] + 3. * x[0] + 4. * x[1];
     ok &= dy[1] == 1. * 7.   + 2. * 8.   + 3. * 0.   + 4. * 0.;
     ok &= dy[2] == 1. * 0.   + 2. * 0.   + 3. * 5.   + 4. * 6.;
     ok &= dy[3] == 1. * 0.   + 2. * 0.   + 3. * 0.   + 4. * 0.;

     //----------------------------------------------------------------------
     // Test second order forward mode
     // g_0^2 (x) = [ 0, 0, 1, 0 ], g_0^2 (x) * [1] = [3]
     //             [ 0, 0, 0, 1 ]              [2]   [4]
     //             [ 1, 0, 0, 0 ]              [3]   [1]
     //             [ 0, 1, 0, 0 ]              [4]   [2]
     CppAD::vector<double> ddx( X.size() ), ddy(m);
     for(j = 0; j <  X.size() ; j++)
          ddx[j] = 0.;
     ddy = G.Forward(2, ddx);
     // [1, 2, 3, 4] * g_0^2 (x) * [1, 2, 3, 4]^T = 1*3 + 2*4 + 3*1 + 4*2
     ok &= 2. * ddy[0] == 1. * 3. + 2. * 4. + 3. * 1. + 4. * 2.;
     // for i > 0, [1, 2, 3, 4] * g_i^2 (x) * [1, 2, 3, 4]^T = 0
     ok &= ddy[1] == 0.;
     ok &= ddy[2] == 0.;
     ok &= ddy[3] == 0.;

     //----------------------------------------------------------------------
     // Test second order reverse mode
     CppAD::vector<double> w(m), dw(2 *  X.size() );
     for(i = 0; i < m; i++)
          w[i] = 0.;
     w[0] = 1.;
     dw = G.Reverse(2, w);
     // g_0'(x) = [ x2, x3, x0, x1 ]
     ok &= dw[0*2 + 0] == x[2];
     ok &= dw[1*2 + 0] == x[3];
     ok &= dw[2*2 + 0] == x[0];
     ok &= dw[3*2 + 0] == x[1];
     // g_0'(x)   * [1, 2, 3, 4]  = 1 * x2 + 2 * x3 + 3 * x0 + 4 * x1
     // g_0^2 (x) * [1, 2, 3, 4]  = [3, 4, 1, 2]
     ok &= dw[0*2 + 1] == 3.;
     ok &= dw[1*2 + 1] == 4.;
     ok &= dw[2*2 + 1] == 1.;
     ok &= dw[3*2 + 1] == 2.;

     //----------------------------------------------------------------------
     // Test forward and reverse Jacobian sparsity pattern
     /*
     [ x0 , x1 ] * [ x2 , 7 ] = [ x0*x2 + x1*x3 , x0*7 + x1*8 ]
     [ 5  , 6 ]    [ x3 , 8 ]   [ 5*x2  + 6*x3  , 5*7 + 6*8 ]
     so the sparsity pattern should be
     s[0] = {0, 1, 2, 3}
     s[1] = {0, 1}
     s[2] = {2, 3}
     s[3] = {}
     */
     CppAD::vector< std::set<size_t> > r( X.size() ), s(m);
     for(j = 0; j <  X.size() ; j++)
     {     assert( r[j].empty() );
          r[j].insert(j);
     }
     s = G.ForSparseJac( X.size() , r);
     for(j = 0; j <  X.size() ; j++)
     {     // s[0] = {0, 1, 2, 3}
          ok &= s[0].find(j) != s[0].end();
          // s[1] = {0, 1}
          if( j == 0 || j == 1 )
               ok &= s[1].find(j) != s[1].end();
          else     ok &= s[1].find(j) == s[1].end();
          // s[2] = {2, 3}
          if( j == 2 || j == 3 )
               ok &= s[2].find(j) != s[2].end();
          else     ok &= s[2].find(j) == s[2].end();
     }
     // s[3] == {}
     ok &= s[3].empty();

     //----------------------------------------------------------------------
     // Test reverse Jacobian sparsity pattern
     /*
     [ x0 , x1 ] * [ x2 , 7 ] = [ x0*x2 + x1*x3 , x0*7 + x1*8 ]
     [ 5  , 6 ]    [ x3 , 8 ]   [ 5*x2  + 6*x3  , 5*7 + 6*8 ]
     so the sparsity pattern should be
     r[0] = {0, 1, 2, 3}
     r[1] = {0, 1}
     r[2] = {2, 3}
     r[3] = {}
     */
     for(i = 0; i <  m; i++)
     {     s[i].clear();
          s[i].insert(i);
     }
     r = G.RevSparseJac(m, s);
     for(j = 0; j <  X.size() ; j++)
     {     // r[0] = {0, 1, 2, 3}
          ok &= r[0].find(j) != r[0].end();
          // r[1] = {0, 1}
          if( j == 0 || j == 1 )
               ok &= r[1].find(j) != r[1].end();
          else     ok &= r[1].find(j) == r[1].end();
          // r[2] = {2, 3}
          if( j == 2 || j == 3 )
               ok &= r[2].find(j) != r[2].end();
          else     ok &= r[2].find(j) == r[2].end();
     }
     // r[3] == {}
     ok &= r[3].empty();

     //----------------------------------------------------------------------
     /* Test reverse Hessian sparsity pattern
     g_0^2 (x) = [ 0, 0, 1, 0 ] and for i > 0, g_i^2 = 0
                 [ 0, 0, 0, 1 ]
                 [ 1, 0, 0, 0 ]
                 [ 0, 1, 0, 0 ]
     so for the sparsity pattern for the first component of g is
     h[0] = {2}
     h[1] = {3}
     h[2] = {0}
     h[3] = {1}
     */
     CppAD::vector< std::set<size_t> > h( X.size() ), t(1);
     t[0].clear();
     t[0].insert(0);
     h = G.RevSparseHes(X.size() , t);
     size_t check[] = {2, 3, 0, 1};
     for(j = 0; j <  X.size() ; j++)
     {     // h[j] = { check[j] }
          for(i = 0; i < n; i++)
          {     if( i == check[j] )
                    ok &= h[j].find(i) != h[j].end();
               else     ok &= h[j].find(i) == h[j].end();
          }
     }
     t[0].clear();
     for( j = 1; j < X.size(); j++)
               t[0].insert(j);
     h = G.RevSparseHes(X.size() , t);
     for(j = 0; j <  X.size() ; j++)
     {     // h[j] = { }
          for(i = 0; i < X.size(); i++)
               ok &= h[j].find(i) == h[j].end();
     }

     // --------------------------------------------------------------------
     // Free temporary work space. (If there are future calls to
     // old_mat_mul they would create new temporary work space.)
     CppAD::user_atomic<double>::clear();
     info_.clear();

     return ok;
}

Input File: example/deprecated/old_mat_mul.cpp