void Split(const arma::Mat<T>& input,
const arma::Row<U>& inputLabel,
arma::Mat<T>& trainData,
arma::Mat<T>& testData,
arma::Row<U>& trainLabel,
arma::Row<U>& testLabel,
const double testRatio)
{
const size_t testSize = static_cast<size_t>(input.n_cols * testRatio);
const size_t trainSize = input.n_cols - testSize;
trainData.set_size(input.n_rows, trainSize);
testData.set_size(input.n_rows, testSize);
trainLabel.set_size(trainSize);
testLabel.set_size(testSize);
const arma::Col<size_t> order =
arma::shuffle(arma::linspace<arma::Col<size_t>>(0, input.n_cols - 1,
input.n_cols));
for (size_t i = 0; i != trainSize; ++i)
{
trainData.col(i) = input.col(order[i]);
trainLabel(i) = inputLabel(order[i]);
}
for (size_t i = 0; i != testSize; ++i)
{
testData.col(i) = input.col(order[i + trainSize]);
testLabel(i) = inputLabel(order[i + trainSize]);
}
}
inline ParallelKinematicMachine3PRPR::ParallelKinematicMachine3PRPR() noexcept {
setMinimalActiveJointActuations({0.1, 0.1, 0.1});
setMinimalActiveJointActuations({1.2, 1.2, 1.2});
setEndEffectorJointPositions({
-0.000066580445834, 0.106954081945581,
-0.092751709777083, -0.053477040972790,
0.092818290222917, -0.053477040972790});
setRedundantJointStartPositions({
0.1, 1.0392,
0.0, 0.8,
1.2, 0.8});
setRedundantJointEndPositions({
1.1, 1.0392,
0.0, -0.2,
1.2, -0.2});
redundantJointStartToEndPositions_ = redundantJointEndPositions_ - redundantJointStartPositions_;
redundantJointIndicies_ = arma::find(arma::any(redundantJointStartToEndPositions_));
redundantJointAngleSines_.set_size(redundantJointIndicies_.n_elem);
redundantJointAngleCosines_.set_size(redundantJointIndicies_.n_elem);
for (std::size_t n = 0; n < redundantJointIndicies_.n_elem; ++n) {
const double redundantJointAngle = std::atan2(redundantJointStartToEndPositions_(1, n), redundantJointStartToEndPositions_(0, n));
redundantJointAngleSines_(n) = std::sin(redundantJointAngle);
redundantJointAngleCosines_(n) = std::cos(redundantJointAngle);
}
}
void AdaBoost<MatType, WeakLearner>::Classify(
const MatType& test,
arma::Row<size_t>& predictedLabels)
{
arma::Row<size_t> tempPredictedLabels(test.n_cols);
arma::mat cMatrix(classes, test.n_cols);
cMatrix.zeros();
predictedLabels.set_size(test.n_cols);
for (size_t i = 0; i < wl.size(); i++)
{
wl[i].Classify(test, tempPredictedLabels);
for (size_t j = 0; j < tempPredictedLabels.n_cols; j++)
cMatrix(tempPredictedLabels(j), j) += (alpha[i] * tempPredictedLabels(j));
}
arma::colvec cMRow;
arma::uword maxIndex;
for (size_t i = 0; i < predictedLabels.n_cols; i++)
{
cMRow = cMatrix.unsafe_col(i);
cMRow.max(maxIndex);
predictedLabels(i) = maxIndex;
}
}
void NaiveBayesClassifier<MatType>::Classify(const MatType& data,
arma::Row<size_t>& results)
{
// Check that the number of features in the test data is same as in the
// training data.
Log::Assert(data.n_rows == means.n_rows);
arma::vec probs = arma::log(probabilities);
arma::mat invVar = 1.0 / variances;
arma::mat testProbs = arma::repmat(probs.t(), data.n_cols, 1);
results.set_size(data.n_cols); // No need to fill with anything yet.
Log::Info << "Running Naive Bayes classifier on " << data.n_cols
<< " data points with " << data.n_rows << " features each." << std::endl;
// Calculate the joint probability for each of the data points for each of the
// means.n_cols.
// Loop over every class.
for (size_t i = 0; i < means.n_cols; i++)
{
// This is an adaptation of gmm::phi() for the case where the covariance is
// a diagonal matrix.
arma::mat diffs = data - arma::repmat(means.col(i), 1, data.n_cols);
arma::mat rhs = -0.5 * arma::diagmat(invVar.col(i)) * diffs;
arma::vec exponents(diffs.n_cols);
for (size_t j = 0; j < diffs.n_cols; ++j) // log(exp(value)) == value
exponents(j) = arma::accu(diffs.col(j) % rhs.unsafe_col(j));
// Calculate probability as sum of logarithm to decrease floating point
// errors.
testProbs.col(i) += (data.n_rows / -2.0 * log(2 * M_PI) - 0.5 *
log(arma::det(arma::diagmat(variances.col(i)))) + exponents);
}
// Now calculate the label.
for (size_t i = 0; i < data.n_cols; ++i)
{
// Find the index of the class with maximum probability for this point.
arma::uword maxIndex = 0;
arma::vec pointProbs = testProbs.row(i).t();
pointProbs.max(maxIndex);
results[i] = maxIndex;
}
return;
}
void DecisionStump<MatType>::Classify(const MatType& test,
arma::Row<size_t>& predictedLabels)
{
predictedLabels.set_size(test.n_cols);
for (size_t i = 0; i < test.n_cols; i++)
{
// Determine which bin the test point falls into.
// Assume first that it falls into the first bin, then proceed through the
// bins until it is known which bin it falls into.
size_t bin = 0;
const double val = test(splitDimension, i);
while (bin < split.n_elem - 1)
{
if (val < split(bin + 1))
break;
++bin;
}
predictedLabels(i) = binLabels(bin);
}
}
void RefinedStart::Cluster(const MatType& data,
const size_t clusters,
arma::Row<size_t>& assignments) const
{
// Perform the Bradley-Fayyad refined start algorithm, and get initial
// centroids back.
arma::mat centroids;
Cluster(data, clusters, centroids);
// Turn the final centroids into assignments.
assignments.set_size(data.n_cols);
for (size_t i = 0; i < data.n_cols; ++i)
{
// Find the closest centroid to this point.
double minDistance = std::numeric_limits<double>::infinity();
size_t closestCluster = clusters;
for (size_t j = 0; j < clusters; ++j)
{
// This is restricted to the L2 distance, and unfortunately it would take
// a lot of refactoring and redesign to make this more general... we would
// probably need to have KMeans take a template template parameter for the
// initial partition policy. It's not clear how to best do this.
const double distance = metric::EuclideanDistance::Evaluate(data.col(i),
centroids.col(j));
if (distance < minDistance)
{
minDistance = distance;
closestCluster = j;
}
}
// Assign the point to its closest cluster.
assignments[i] = closestCluster;
}
}
