New translations svmpredict.c (Chinese Simplified)

lang/zh/gklearn/gedlib/lib/libsvm.3.22/matlab/svmpredict.c

@@ -0,0 +1,370 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "svm.h"
+
+#include "mex.h"
+#include "svm_model_matlab.h"
+
+#ifdef MX_API_VER
+#if MX_API_VER < 0x07030000
+typedef int mwIndex;
+#endif
+#endif
+
+#define CMD_LEN 2048
+
+int print_null(const char *s,...) {}
+int (*info)(const char *fmt,...) = &mexPrintf;
+
+void read_sparse_instance(const mxArray *prhs, int index, struct svm_node *x)
+{
+	int i, j, low, high;
+	mwIndex *ir, *jc;
+	double *samples;
+
+	ir = mxGetIr(prhs);
+	jc = mxGetJc(prhs);
+	samples = mxGetPr(prhs);
+
+	// each column is one instance
+	j = 0;
+	low = (int)jc[index], high = (int)jc[index+1];
+	for(i=low;i<high;i++)
+	{
+		x[j].index = (int)ir[i] + 1;
+		x[j].value = samples[i];
+		j++;
+	}
+	x[j].index = -1;
+}
+
+static void fake_answer(int nlhs, mxArray *plhs[])
+{
+	int i;
+	for(i=0;i<nlhs;i++)
+		plhs[i] = mxCreateDoubleMatrix(0, 0, mxREAL);
+}
+
+void predict(int nlhs, mxArray *plhs[], const mxArray *prhs[], struct svm_model *model, const int predict_probability)
+{
+	int label_vector_row_num, label_vector_col_num;
+	int feature_number, testing_instance_number;
+	int instance_index;
+	double *ptr_instance, *ptr_label, *ptr_predict_label; 
+	double *ptr_prob_estimates, *ptr_dec_values, *ptr;
+	struct svm_node *x;
+	mxArray *pplhs[1]; // transposed instance sparse matrix
+	mxArray *tplhs[3]; // temporary storage for plhs[]
+
+	int correct = 0;
+	int total = 0;
+	double error = 0;
+	double sump = 0, sumt = 0, sumpp = 0, sumtt = 0, sumpt = 0;
+
+	int svm_type=svm_get_svm_type(model);
+	int nr_class=svm_get_nr_class(model);
+	double *prob_estimates=NULL;
+
+	// prhs[1] = testing instance matrix
+	feature_number = (int)mxGetN(prhs[1]);
+	testing_instance_number = (int)mxGetM(prhs[1]);
+	label_vector_row_num = (int)mxGetM(prhs[0]);
+	label_vector_col_num = (int)mxGetN(prhs[0]);
+
+	if(label_vector_row_num!=testing_instance_number)
+	{
+		mexPrintf("Length of label vector does not match # of instances.\n");
+		fake_answer(nlhs, plhs);
+		return;
+	}
+	if(label_vector_col_num!=1)
+	{
+		mexPrintf("label (1st argument) should be a vector (# of column is 1).\n");
+		fake_answer(nlhs, plhs);
+		return;
+	}
+
+	ptr_instance = mxGetPr(prhs[1]);
+	ptr_label    = mxGetPr(prhs[0]);
+
+	// transpose instance matrix
+	if(mxIsSparse(prhs[1]))
+	{
+		if(model->param.kernel_type == PRECOMPUTED)
+		{
+			// precomputed kernel requires dense matrix, so we make one
+			mxArray *rhs[1], *lhs[1];
+			rhs[0] = mxDuplicateArray(prhs[1]);
+			if(mexCallMATLAB(1, lhs, 1, rhs, "full"))
+			{
+				mexPrintf("Error: cannot full testing instance matrix\n");
+				fake_answer(nlhs, plhs);
+				return;
+			}
+			ptr_instance = mxGetPr(lhs[0]);
+			mxDestroyArray(rhs[0]);
+		}
+		else
+		{
+			mxArray *pprhs[1];
+			pprhs[0] = mxDuplicateArray(prhs[1]);
+			if(mexCallMATLAB(1, pplhs, 1, pprhs, "transpose"))
+			{
+				mexPrintf("Error: cannot transpose testing instance matrix\n");
+				fake_answer(nlhs, plhs);
+				return;
+			}
+		}
+	}
+
+	if(predict_probability)
+	{
+		if(svm_type==NU_SVR || svm_type==EPSILON_SVR)
+			info("Prob. model for test data: target value = predicted value + z,\nz: Laplace distribution e^(-|z|/sigma)/(2sigma),sigma=%g\n",svm_get_svr_probability(model));
+		else
+			prob_estimates = (double *) malloc(nr_class*sizeof(double));
+	}
+
+	tplhs[0] = mxCreateDoubleMatrix(testing_instance_number, 1, mxREAL);
+	if(predict_probability)
+	{
+		// prob estimates are in plhs[2]
+		if(svm_type==C_SVC || svm_type==NU_SVC)
+			tplhs[2] = mxCreateDoubleMatrix(testing_instance_number, nr_class, mxREAL);
+		else
+			tplhs[2] = mxCreateDoubleMatrix(0, 0, mxREAL);
+	}
+	else
+	{
+		// decision values are in plhs[2]
+		if(svm_type == ONE_CLASS ||
+		   svm_type == EPSILON_SVR ||
+		   svm_type == NU_SVR ||
+		   nr_class == 1) // if only one class in training data, decision values are still returned.
+			tplhs[2] = mxCreateDoubleMatrix(testing_instance_number, 1, mxREAL);
+		else
+			tplhs[2] = mxCreateDoubleMatrix(testing_instance_number, nr_class*(nr_class-1)/2, mxREAL);
+	}
+
+	ptr_predict_label = mxGetPr(tplhs[0]);
+	ptr_prob_estimates = mxGetPr(tplhs[2]);
+	ptr_dec_values = mxGetPr(tplhs[2]);
+	x = (struct svm_node*)malloc((feature_number+1)*sizeof(struct svm_node) );
+	for(instance_index=0;instance_index<testing_instance_number;instance_index++)
+	{
+		int i;
+		double target_label, predict_label;
+
+		target_label = ptr_label[instance_index];
+
+		if(mxIsSparse(prhs[1]) && model->param.kernel_type != PRECOMPUTED) // prhs[1]^T is still sparse
+			read_sparse_instance(pplhs[0], instance_index, x);
+		else
+		{
+			for(i=0;i<feature_number;i++)
+			{
+				x[i].index = i+1;
+				x[i].value = ptr_instance[testing_instance_number*i+instance_index];
+			}
+			x[feature_number].index = -1;
+		}
+
+		if(predict_probability)
+		{
+			if(svm_type==C_SVC || svm_type==NU_SVC)
+			{
+				predict_label = svm_predict_probability(model, x, prob_estimates);
+				ptr_predict_label[instance_index] = predict_label;
+				for(i=0;i<nr_class;i++)
+					ptr_prob_estimates[instance_index + i * testing_instance_number] = prob_estimates[i];
+			} else {
+				predict_label = svm_predict(model,x);
+				ptr_predict_label[instance_index] = predict_label;
+			}
+		}
+		else
+		{
+			if(svm_type == ONE_CLASS ||
+			   svm_type == EPSILON_SVR ||
+			   svm_type == NU_SVR)
+			{
+				double res;
+				predict_label = svm_predict_values(model, x, &res);
+				ptr_dec_values[instance_index] = res;
+			}
+			else
+			{
+				double *dec_values = (double *) malloc(sizeof(double) * nr_class*(nr_class-1)/2);
+				predict_label = svm_predict_values(model, x, dec_values);
+				if(nr_class == 1) 
+					ptr_dec_values[instance_index] = 1;
+				else
+					for(i=0;i<(nr_class*(nr_class-1))/2;i++)
+						ptr_dec_values[instance_index + i * testing_instance_number] = dec_values[i];
+				free(dec_values);
+			}
+			ptr_predict_label[instance_index] = predict_label;
+		}
+
+		if(predict_label == target_label)
+			++correct;
+		error += (predict_label-target_label)*(predict_label-target_label);
+		sump += predict_label;
+		sumt += target_label;
+		sumpp += predict_label*predict_label;
+		sumtt += target_label*target_label;
+		sumpt += predict_label*target_label;
+		++total;
+	}
+	if(svm_type==NU_SVR || svm_type==EPSILON_SVR)
+	{
+		info("Mean squared error = %g (regression)\n",error/total);
+		info("Squared correlation coefficient = %g (regression)\n",
+			((total*sumpt-sump*sumt)*(total*sumpt-sump*sumt))/
+			((total*sumpp-sump*sump)*(total*sumtt-sumt*sumt))
+			);
+	}
+	else
+		info("Accuracy = %g%% (%d/%d) (classification)\n",
+			(double)correct/total*100,correct,total);
+
+	// return accuracy, mean squared error, squared correlation coefficient
+	tplhs[1] = mxCreateDoubleMatrix(3, 1, mxREAL);
+	ptr = mxGetPr(tplhs[1]);
+	ptr[0] = (double)correct/total*100;
+	ptr[1] = error/total;
+	ptr[2] = ((total*sumpt-sump*sumt)*(total*sumpt-sump*sumt))/
+				((total*sumpp-sump*sump)*(total*sumtt-sumt*sumt));
+
+	free(x);
+	if(prob_estimates != NULL)
+		free(prob_estimates);
+
+	switch(nlhs)
+	{
+		case 3:
+			plhs[2] = tplhs[2];
+			plhs[1] = tplhs[1];
+		case 1:
+		case 0:
+			plhs[0] = tplhs[0];
+	}
+}
+
+void exit_with_help()
+{
+	mexPrintf(
+		"Usage: [predicted_label, accuracy, decision_values/prob_estimates] = svmpredict(testing_label_vector, testing_instance_matrix, model, 'libsvm_options')\n"
+		"       [predicted_label] = svmpredict(testing_label_vector, testing_instance_matrix, model, 'libsvm_options')\n"
+		"Parameters:\n"
+		"  model: SVM model structure from svmtrain.\n"
+		"  libsvm_options:\n"
+		"    -b probability_estimates: whether to predict probability estimates, 0 or 1 (default 0); one-class SVM not supported yet\n"
+		"    -q : quiet mode (no outputs)\n"
+		"Returns:\n"
+		"  predicted_label: SVM prediction output vector.\n"
+		"  accuracy: a vector with accuracy, mean squared error, squared correlation coefficient.\n"
+		"  prob_estimates: If selected, probability estimate vector.\n"
+	);
+}
+
+void mexFunction( int nlhs, mxArray *plhs[],
+		 int nrhs, const mxArray *prhs[] )
+{
+	int prob_estimate_flag = 0;
+	struct svm_model *model;
+	info = &mexPrintf;
+
+	if(nlhs == 2 || nlhs > 3 || nrhs > 4 || nrhs < 3)
+	{
+		exit_with_help();
+		fake_answer(nlhs, plhs);
+		return;
+	}
+
+	if(!mxIsDouble(prhs[0]) || !mxIsDouble(prhs[1])) {
+		mexPrintf("Error: label vector and instance matrix must be double\n");
+		fake_answer(nlhs, plhs);
+		return;
+	}
+
+	if(mxIsStruct(prhs[2]))
+	{
+		const char *error_msg;
+
+		// parse options
+		if(nrhs==4)
+		{
+			int i, argc = 1;
+			char cmd[CMD_LEN], *argv[CMD_LEN/2];
+
+			// put options in argv[]
+			mxGetString(prhs[3], cmd,  mxGetN(prhs[3]) + 1);
+			if((argv[argc] = strtok(cmd, " ")) != NULL)
+				while((argv[++argc] = strtok(NULL, " ")) != NULL)
+					;
+
+			for(i=1;i<argc;i++)
+			{
+				if(argv[i][0] != '-') break;
+				if((++i>=argc) && argv[i-1][1] != 'q')
+				{
+					exit_with_help();
+					fake_answer(nlhs, plhs);
+					return;
+				}
+				switch(argv[i-1][1])
+				{
+					case 'b':
+						prob_estimate_flag = atoi(argv[i]);
+						break;
+					case 'q':
+						i--;
+						info = &print_null;
+						break;
+					default:
+						mexPrintf("Unknown option: -%c\n", argv[i-1][1]);
+						exit_with_help();
+						fake_answer(nlhs, plhs);
+						return;
+				}
+			}
+		}
+
+		model = matlab_matrix_to_model(prhs[2], &error_msg);
+		if (model == NULL)
+		{
+			mexPrintf("Error: can't read model: %s\n", error_msg);
+			fake_answer(nlhs, plhs);
+			return;
+		}
+
+		if(prob_estimate_flag)
+		{
+			if(svm_check_probability_model(model)==0)
+			{
+				mexPrintf("Model does not support probabiliy estimates\n");
+				fake_answer(nlhs, plhs);
+				svm_free_and_destroy_model(&model);
+				return;
+			}
+		}
+		else
+		{
+			if(svm_check_probability_model(model)!=0)
+				info("Model supports probability estimates, but disabled in predicton.\n");
+		}
+
+		predict(nlhs, plhs, prhs, model, prob_estimate_flag);
+		// destroy model
+		svm_free_and_destroy_model(&model);
+	}
+	else
+	{
+		mexPrintf("model file should be a struct array\n");
+		fake_answer(nlhs, plhs);
+	}
+
+	return;
+}