void prepare_to_train( const Mat& inputs, const Mat& outputs,
Mat& sample_weights, int flags )
{
if( layer_sizes.empty() )
CV_Error( CV_StsError,
"The network has not been created. Use method create or the appropriate constructor" );
if( (inputs.type() != CV_32F && inputs.type() != CV_64F) ||
inputs.cols != layer_sizes[0] )
CV_Error( CV_StsBadArg,
"input training data should be a floating-point matrix with "
"the number of rows equal to the number of training samples and "
"the number of columns equal to the size of 0-th (input) layer" );
if( (outputs.type() != CV_32F && outputs.type() != CV_64F) ||
outputs.cols != layer_sizes.back() )
CV_Error( CV_StsBadArg,
"output training data should be a floating-point matrix with "
"the number of rows equal to the number of training samples and "
"the number of columns equal to the size of last (output) layer" );
if( inputs.rows != outputs.rows )
CV_Error( CV_StsUnmatchedSizes, "The numbers of input and output samples do not match" );
Mat temp;
double s = sum(sample_weights)[0];
sample_weights.convertTo(temp, CV_64F, 1./s);
sample_weights = temp;
calc_input_scale( inputs, flags );
calc_output_scale( outputs, flags );
}
bool CvANN_MLP::prepare_to_train( const CvMat* _inputs, const CvMat* _outputs,
const CvMat* _sample_weights, const CvMat* _sample_idx,
CvVectors* _ivecs, CvVectors* _ovecs, double** _sw, int _flags )
{
bool ok = false;
CvMat* sample_idx = 0;
CvVectors ivecs, ovecs;
double* sw = 0;
int count = 0;
CV_FUNCNAME( "CvANN_MLP::prepare_to_train" );
ivecs.data.ptr = ovecs.data.ptr = 0;
assert( _ivecs && _ovecs );
__BEGIN__;
const int* sidx = 0;
int i, sw_type = 0, sw_count = 0;
int sw_step = 0;
double sw_sum = 0;
if( !layer_sizes )
CV_ERROR( CV_StsError,
"The network has not been created. Use method create or the appropriate constructor" );
if( !CV_IS_MAT(_inputs) || CV_MAT_TYPE(_inputs->type) != CV_32FC1 &&
CV_MAT_TYPE(_inputs->type) != CV_64FC1 || _inputs->cols != layer_sizes->data.i[0] )
CV_ERROR( CV_StsBadArg,
"input training data should be a floating-point matrix with"
"the number of rows equal to the number of training samples and "
"the number of columns equal to the size of 0-th (input) layer" );
if( !CV_IS_MAT(_outputs) || CV_MAT_TYPE(_outputs->type) != CV_32FC1 &&
CV_MAT_TYPE(_outputs->type) != CV_64FC1 ||
_outputs->cols != layer_sizes->data.i[layer_sizes->cols - 1] )
CV_ERROR( CV_StsBadArg,
"output training data should be a floating-point matrix with"
"the number of rows equal to the number of training samples and "
"the number of columns equal to the size of last (output) layer" );
if( _inputs->rows != _outputs->rows )
CV_ERROR( CV_StsUnmatchedSizes, "The numbers of input and output samples do not match" );
if( _sample_idx )
{
CV_CALL( sample_idx = cvPreprocessIndexArray( _sample_idx, _inputs->rows ));
sidx = sample_idx->data.i;
count = sample_idx->cols + sample_idx->rows - 1;
}
else
count = _inputs->rows;
if( _sample_weights )
{
if( !CV_IS_MAT(_sample_weights) )
CV_ERROR( CV_StsBadArg, "sample_weights (if passed) must be a valid matrix" );
sw_type = CV_MAT_TYPE(_sample_weights->type);
sw_count = _sample_weights->cols + _sample_weights->rows - 1;
if( sw_type != CV_32FC1 && sw_type != CV_64FC1 ||
_sample_weights->cols != 1 && _sample_weights->rows != 1 ||
sw_count != count && sw_count != _inputs->rows )
CV_ERROR( CV_StsBadArg,
"sample_weights must be 1d floating-point vector containing weights "
"of all or selected training samples" );
sw_step = CV_IS_MAT_CONT(_sample_weights->type) ? 1 :
_sample_weights->step/CV_ELEM_SIZE(sw_type);
CV_CALL( sw = (double*)cvAlloc( count*sizeof(sw[0]) ));
}
CV_CALL( ivecs.data.ptr = (uchar**)cvAlloc( count*sizeof(ivecs.data.ptr[0]) ));
CV_CALL( ovecs.data.ptr = (uchar**)cvAlloc( count*sizeof(ovecs.data.ptr[0]) ));
ivecs.type = CV_MAT_TYPE(_inputs->type);
ovecs.type = CV_MAT_TYPE(_outputs->type);
ivecs.count = ovecs.count = count;
for( i = 0; i < count; i++ )
{
int idx = sidx ? sidx[i] : i;
ivecs.data.ptr[i] = _inputs->data.ptr + idx*_inputs->step;
ovecs.data.ptr[i] = _outputs->data.ptr + idx*_outputs->step;
if( sw )
{
int si = sw_count == count ? i : idx;
double w = sw_type == CV_32FC1 ?
(double)_sample_weights->data.fl[si*sw_step] :
_sample_weights->data.db[si*sw_step];
sw[i] = w;
if( w < 0 )
CV_ERROR( CV_StsOutOfRange, "some of sample weights are negative" );
sw_sum += w;
}
}
// normalize weights
if( sw )
{
sw_sum = sw_sum > DBL_EPSILON ? 1./sw_sum : 0;
for( i = 0; i < count; i++ )
sw[i] *= sw_sum;
}
calc_input_scale( &ivecs, _flags );
CV_CALL( calc_output_scale( &ovecs, _flags ));
ok = true;
__END__;
if( !ok )
{
cvFree( &ivecs.data.ptr );
cvFree( &ovecs.data.ptr );
cvFree( &sw );
}
cvReleaseMat( &sample_idx );
*_ivecs = ivecs;
*_ovecs = ovecs;
*_sw = sw;
return ok;
}