com.insightml.data.features.stats.FeaturesImportance.java Source code

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Here is the source code for com.insightml.data.features.stats.FeaturesImportance.java

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/*
 * Copyright (C) 2016 Stefan Hen
 *
 * 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 com.insightml.data.features.stats;

import java.util.Map;
import java.util.Map.Entry;

import com.google.common.base.Functions;
import com.google.common.collect.ImmutableSortedMap;
import com.google.common.collect.Ordering;
import com.insightml.data.samples.ISamples;
import com.insightml.utils.ui.SimpleFormatter;
import com.insightml.utils.ui.UiUtils;
import com.insightml.utils.ui.reports.IUiProvider;

public final class FeaturesImportance implements IUiProvider<ISamples<?, Double>> {

    @Override
    public String getText(final ISamples<?, Double> instances, final int labelIndex) {
        final FeatureStatistics stats = new FeatureStatistics(instances, labelIndex);
        final Map<String, Double> mi = new MutualInformation(0.1).run(stats);
        final Map<String, Double> chi = new ChiSquare(0.1).run(stats);
        final StringBuilder builder = new StringBuilder(1024);
        final SimpleFormatter formatter = new SimpleFormatter(5, true);
        for (final Entry<String, Double> feature : ImmutableSortedMap
                .copyOf(mi, Ordering.natural().reverse().onResultOf(Functions.forMap(mi))).entrySet()) {
            builder.append(UiUtils.fill(feature.getKey(), 25) + "\t");
            builder.append("MutualInformation: " + UiUtils.fill(formatter.format(feature.getValue()), 12));
            builder.append("ChiSquare: " + UiUtils.fill(formatter.format(chi.get(feature.getKey())), 12));
            builder.append("\n");
        }
        return builder.toString();
    }

}