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<center><b><big><big>Sacado Speed: Gradient of Determinant by Minor Expansion</big></big></b></center>
<br/>
<b><big><a name="Specifications" id="Specifications">Specifications</a></big></b>
<br/>
See <a href="link_det_minor.xml" target="_top"><span style='white-space: nowrap'>link_det_minor</span></a>
.

<br/>
<br/>
<b><big><a name="Implementation" id="Implementation">Implementation</a></big></b>


<code><font color='blue'><pre style='display:inline'> 
# include &lt;Sacado.hpp&gt;
# include &lt;cppad/speed/det_by_minor.hpp&gt;
# include &lt;cppad/speed/uniform_01.hpp&gt;
# include &lt;cppad/vector.hpp&gt;

// list of possible options
extern bool global_memory, global_onetape, global_atomic, global_optimize;
extern bool global_boolsparsity;

bool link_det_minor(
	size_t                     size     , 
	size_t                     repeat   , 
	CppAD::vector&lt;double&gt;     &amp;matrix   ,
	CppAD::vector&lt;double&gt;     &amp;gradient )
{
	// speed test global option values
	if( global_atomic || global_boolsparsity )
		return false; 
	if( global_memory || global_onetape || global_optimize )
		return false; 
	// -----------------------------------------------------
	// setup

	// object for computing determinant
	typedef Sacado::Rad::ADvar&lt;double&gt;    ADScalar; 
	typedef CppAD::vector&lt;ADScalar&gt;       ADVector; 
	CppAD::det_by_minor&lt;ADScalar&gt;         Det(size);

	size_t i;                // temporary index
	size_t n = size * size;  // number of independent variables
	ADScalar   detA;         // AD value of the determinant
	ADVector   A(n);         // AD version of matrix 
	
	// ------------------------------------------------------
	while(repeat--)
	{	// get the next matrix
		CppAD::uniform_01(n, matrix);

		// set independent variable values
		for(i = 0; i &lt; n; i++)
			A[i] = matrix[i];

		// compute the determinant
		detA = Det(A);

		// reverse mode compute gradient of last computed value; i.e., detA
		ADScalar::Gradcomp();

		// return gradient 
		for(i =0; i &lt; n; i++)
			gradient[i] = A[i].adj(); // partial detA w.r.t A[i]
	}
	// ---------------------------------------------------------
	return true;
}
</pre></font></code>


<hr/>Input File: speed/sacado/det_minor.cpp

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