/**
* Creates a frequency table. The number of items in each class is returned. Classes are defined
* by the limit and resolution. E.g. for a limit of 1200 with a resolution of 400 there are 3
* classes: [0-400[, [400-800[ and [800-1200[.
*
* @param values the data to distribute over the bins/classes.
* @param classWidth the resolution or the with of the classes
* @param start the starting value
* @param stop the stopping value
* @return The number of items in each class
*/
public static Histogram createFrequencyTable(
final List<Double> values, final double classWidth, final double start, final double stop) {
final Histogram histogram = new Histogram(start, stop, (int) ((stop - start) / classWidth));
for (final Double value : values) {
histogram.add(value);
}
assert histogram.getSumFreq() == values.size()
: "Number of items in bins does no" + "t correspond with total number of items";
return histogram;
}
/**
* Reads a frequency table (histogram) from disk. The source file is expected to be a CSV-file in
* the format: <code>value;frequency[;other data; is discarded;...]</code> The lowest value is on
* the first row, the highest on the last!
*
* @param fileName
* @return a frequencytable
*/
public static Histogram readFrequencyTable(final String fileName) {
final List<String[]> data = FileUtils.readCSVFile(fileName, ";", -1);
final double classWidth =
Double.parseDouble(data.get(1)[0]) - Double.parseDouble(data.get(0)[0]);
final double start = Double.parseDouble(data.get(0)[0]) - classWidth / 2.0;
final double stop = Double.parseDouble(data.get(data.size() - 1)[0]) + classWidth / 2.0;
final Histogram table = new Histogram(start, stop, (int) ((stop - start) / classWidth));
for (final String[] row : data) {
final int frequency = (int) Double.parseDouble(row[1]);
final double value = Double.parseDouble(row[0]);
for (int i = 0; i < frequency; i++) {
table.add(value);
}
}
return table;
}
public static void exportFrequencyTable(final Histogram histogram, final String fileName) {
exportFrequencyTable(histogram, fileName, histogram.getStart(), histogram.getStop());
}
public static void exportFrequencyTable(
final Histogram histogram, final String fileName, final double start, final double stop) {
final StringBuilder sb = new StringBuilder();
for (double current = start + histogram.getClassWidth() / 2;
current <= stop;
current += histogram.getClassWidth()) {
final double count = histogram.getCount(current);
final long cumFreq = histogram.getCumFreq(current);
final double derivative =
current + histogram.getClassWidth() > stop
? 0
: (histogram.getCount(current)
- histogram.getCount(current + histogram.getClassWidth()))
/ histogram.getClassWidth();
double psd = 0.0;
if (current + 2 * histogram.getClassWidth() <= stop) {
psd =
(histogram.getCount(current + 2 * histogram.getClassWidth())
- histogram.getCount(current))
/ (2 * histogram.getClassWidth());
}
// double derivative = (current + frequencyTable.getClassWidth() <=
// stop)? 0 : (frequencyTable.getCount(current +
// frequencyTable.getClassWidth()) -
// frequencyTable.getCount(current))
// /frequencyTable.getClassWidth();
sb.append(current)
.append(";")
.append(count)
.append(";")
.append(cumFreq)
.append(";")
.append(derivative)
.append(";")
.append(psd)
.append("\n");
}
FileUtils.writeFile(sb.toString(), fileName);
final Plot h = new Plot();
h.setXRange(start, stop);
boolean first = true;
double highWaterMark = 0;
final double[] values = new double[histogram.getNumberOfClasses()];
int i = 0;
for (double current = start + histogram.getClassWidth() / 2;
current <= stop;
current += histogram.getClassWidth()) {
h.addPoint(0, current, histogram.getCount(current), !first);
values[i] = histogram.getCount(current);
if (histogram.getCount(current) > highWaterMark) {
highWaterMark = histogram.getCount(current);
}
i++;
first = false;
}
/*
* List<Peak> peaks = PeakDetector.peakDetection(histogram,fileName +
* ".midi", start, stop); int peakIndex = 1; for(Peak peak:peaks){ int
* position = peak.getPosition();
* h.addPoint(1,peak.getLift(),peak.getLTop(),false);
* h.addPoint(1,position,peak.getTop(),true);
* h.addPoint(1,peak.getRight(),peak.getRTop(),true); peakIndex++; }
*/
if (stop == 1200.0) {
h.setXLabel("n (cents)");
h.setYLabel("frequency of ocurrence");
// h.addLegend(0,"Pitch histogram");
for (int j = 0; j <= 1200; j += 100) {
h.addXTick(j + "", j);
}
/*
* h.addXTick("Fifth", reference - 700); h.addXTick("Fifth",
* reference + 700); h.addXTick("Tritonus", reference - 600);
* h.addXTick("Tritonus", reference + 600);
* h.addXTick("Kleine terts",reference + 300);
* h.addXTick("Kleine terts",reference - 300);
* h.addXTick("Grote terts",reference + 400);
* h.addXTick("Grote terts",reference - 400); h.setWrap(true);
*/
// h.addYTick("Gem", histogram.getSumFreq() / (float)
// histogram.getNumberOfClasses());
// h.addYTick("Med", StatUtils.percentile(values, 0.5));
// h.setXRange(43, 1147);
}
h.setSize(1024, 786);
h.setTitle(FileUtils.basename(fileName));
try {
Thread.sleep(60);
final BufferedImage image = h.exportImage();
ImageIO.write(image, "png", new File(fileName.substring(0, fileName.length() - 4) + ".png"));
} catch (final IOException e) {
e.printStackTrace();
} catch (final InterruptedException e1) {
e1.printStackTrace();
}
}