int* weightedCondMI(uint k, uint noOfSamples, uint noOfFeatures, uint **featureMatrix, uint *classColumn, double *weightVector, int *outputFeatures, double *featureScores) {
char *selectedFeatures = (char *) checkedCalloc(noOfFeatures,sizeof(char));
/*holds the class MI values*/
double *classMI = (double *) checkedCalloc(noOfFeatures,sizeof(double));
/*Changed to ensure it always picks a feature*/
double maxMI = -1.0;
int maxMICounter = -1;
double score, currentScore;
int currentHighestFeature;
uint *conditionVector = (uint *) checkedCalloc(noOfSamples,sizeof(uint));
int i,j;
for (j = 0; j < k; j++) {
outputFeatures[j] = -1;
}
for (i = 0; i < noOfFeatures; i++) {
/*calculate mutual info
**double calcWeightedMutualInformation(uint *firstVector, uint *secondVector, uint *weightVector, int vectorLength);
*/
classMI[i] = calcWeightedMutualInformation(featureMatrix[i],classColumn,weightVector,noOfSamples);
if (classMI[i] > maxMI) {
maxMI = classMI[i];
maxMICounter = i;
}/*if bigger than current maximum*/
}/*for noOfFeatures - filling classMI*/
selectedFeatures[maxMICounter] = 1;
outputFeatures[0] = maxMICounter;
featureScores[0] = maxMI;
memcpy(conditionVector,featureMatrix[maxMICounter],sizeof(int)*noOfSamples);
/*****************************************************************************
** We have populated the classMI array, and selected the highest
** MI feature as the first output feature
** Now we move into the CondMI algorithm
*****************************************************************************/
for (i = 1; i < k; i++) {
score = 0.0;
currentHighestFeature = -1;
currentScore = 0.0;
for (j = 0; j < noOfFeatures; j++) {
/*if we haven't selected j*/
if (selectedFeatures[j] == 0) {
currentScore = 0.0;
/*double calcWeightedConditionalMutualInformation(uint *firstVector, uint *targetVector, uint *conditionVector, double *weightVector, int vectorLength);*/
currentScore = calcWeightedConditionalMutualInformation(featureMatrix[j],classColumn,conditionVector,weightVector,noOfSamples);
if (currentScore > score) {
score = currentScore;
currentHighestFeature = j;
}
}/*if j is unselected*/
}/*for number of features*/
outputFeatures[i] = currentHighestFeature;
featureScores[i] = score;
if (currentHighestFeature != -1) {
selectedFeatures[currentHighestFeature] = 1;
mergeArrays(featureMatrix[currentHighestFeature],conditionVector,conditionVector,noOfSamples);
}
}/*for the number of features to select*/
FREE_FUNC(classMI);
FREE_FUNC(conditionVector);
FREE_FUNC(selectedFeatures);
classMI = NULL;
conditionVector = NULL;
selectedFeatures = NULL;
return outputFeatures;
}/*weightedCondMI(uint,uint,uint,uint[][],uint[],double[],int[],double[])*/
uint* weightedCMIM(uint k, uint noOfSamples, uint noOfFeatures, uint **featureMatrix, uint *classColumn, double *weightVector, uint *outputFeatures, double *featureScores) {
/*holds the class MI values
**the class MI doubles as the partial score from the CMIM paper
*/
double *classMI = (double *) checkedCalloc(noOfFeatures,sizeof(double));
/*in the CMIM paper, m = lastUsedFeature*/
uint *lastUsedFeature = (uint *) checkedCalloc(noOfFeatures,sizeof(uint));
double score, conditionalInfo;
int currentFeature;
double maxMI = 0.0;
int maxMICounter = -1;
int j, i;
for (i = 0; i < noOfFeatures; i++) {
classMI[i] = calcWeightedMutualInformation(featureMatrix[i],classColumn,weightVector,noOfSamples);
if (classMI[i] > maxMI) {
maxMI = classMI[i];
maxMICounter = i;
}/*if bigger than current maximum*/
}/*for noOfFeatures - filling classMI*/
outputFeatures[0] = maxMICounter;
featureScores[0] = maxMI;
/*****************************************************************************
** We have populated the classMI array, and selected the highest
** MI feature as the first output feature
** Now we move into the CMIM algorithm
*****************************************************************************/
for (i = 1; i < k; i++) {
score = 0.0;
for (j = 0; j < noOfFeatures; j++) {
while ((classMI[j] > score) && (lastUsedFeature[j] < i)) {
/*double calcWeightedConditionalMutualInformation(uint *firstVector, uint *targetVector, uint *conditionVector, double *weightVector, int vectorLength);*/
currentFeature = outputFeatures[lastUsedFeature[j]];
conditionalInfo = calcWeightedConditionalMutualInformation(featureMatrix[j], classColumn, featureMatrix[currentFeature], weightVector, noOfSamples);
if (classMI[j] > conditionalInfo) {
classMI[j] = conditionalInfo;
}/*reset classMI*/
/*moved due to C indexing from 0 rather than 1*/
lastUsedFeature[j] += 1;
}/*while partial score greater than score & not reached last feature*/
if (classMI[j] > score) {
score = classMI[j];
featureScores[i] = score;
outputFeatures[i] = j;
}/*if partial score still greater than score*/
}/*for number of features*/
}/*for the number of features to select*/
FREE_FUNC(classMI);
FREE_FUNC(lastUsedFeature);
classMI = NULL;
lastUsedFeature = NULL;
return outputFeatures;
}/*weightedCMIM(uint,uint,uint,uint[][],uint[],double[],uint[],double[])*/
