tech.tablesaw.util.DoubleArrays Maven / Gradle / Ivy
/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package tech.tablesaw.util;
import com.google.common.base.Preconditions;
import tech.tablesaw.api.NumericColumn;
import tech.tablesaw.table.TemporaryView;
import tech.tablesaw.table.ViewGroup;
/**
* Utility functions for creating 2D double arrays from columns and other arrays
*/
public class DoubleArrays {
public static double[] toN(int n) {
double[] result = new double[n];
for (int i = 0; i < n; i++) {
result[i] = i;
}
return result;
}
public static double[][] to2dArray(NumericColumn... columns) {
Preconditions.checkArgument(columns.length >= 1);
int obs = columns[0].size();
double[][] allVals = new double[obs][columns.length];
for (int r = 0; r < obs; r++) {
for (int c = 0; c < columns.length; c++) {
allVals[r][c] = columns[c].getFloat(r);
allVals[r][c] = columns[c].getFloat(r);
}
}
return allVals;
}
public static double[][] to2dArray(ViewGroup views, int columnNumber) {
int viewCount = views.size();
double[][] allVals = new double[viewCount][];
for (int viewNumber = 0; viewNumber < viewCount; viewNumber++) {
TemporaryView view = views.get(viewNumber);
allVals[viewNumber] = new double[view.rowCount()];
NumericColumn numericColumn = view.numericColumn(columnNumber);
for (int r = 0; r < view.rowCount(); r++) {
allVals[viewNumber][r] = numericColumn.getFloat(r);
}
}
return allVals;
}
public static double[][] to2dArray(double[] x, double[] y) {
double[][] allVals = new double[x.length][2];
for (int i = 0; i < x.length; i++) {
allVals[i][0] = x[i];
allVals[i][1] = y[i];
}
return allVals;
}
public static double[][] to2dArray(NumericColumn x, NumericColumn y) {
double[][] allVals = new double[x.size()][2];
for (int i = 0; i < x.size(); i++) {
allVals[i][0] = x.getFloat(i);
allVals[i][1] = y.getFloat(i);
}
return allVals;
}
}