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リビジョン d3e9fb9a

高徹 高橋 徹 さんが5年以上前に追加

Add tool to generate random spectrum data file

差分を表示:

src/main/java/com/torutk/spectrum/data/RandomGenerator.java
package com.torutk.spectrum.data;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.channels.SeekableByteChannel;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
import java.util.Random;
/**
* Generating a test spectrum data file by markov model.
*
* recommend parameters
* <ul>
* <li>probability: between 0.65</li>
* <li>upper shift: 2</li>
* <li>lower shift: 4</li>
* </ul>
*
*/
public class RandomGenerator {
private static double startFrequency = 10750d;
private static double stopFrequency = 11750d;
private static float referenceLevel = -30f;
private static float scale = 5f;
private static long numSamples = 10_000;
private static Path outPath;
private static double markovProbability = 0.5;
private static int markovUpperShift = 2;
private static int markovLowerShift = 3;
private static Random random = new Random();
/**
* Entry method.
*
* @param args command line arguments
*/
public static void main(String[] args) throws Exception {
for (int i = 0; i < args.length; i++) {
if ("-f".equals(args[i])) {
outPath = Paths.get(args[++i]);
} else if ("-p".equals(args[i])) {
markovProbability = Double.parseDouble(args[++i]);
} else if ("-u".equals(args[i])) {
markovUpperShift = Integer.parseInt(args[++i]);
} else if ("-l".equals(args[i])) {
markovLowerShift = Integer.parseInt(args[++i]);
} else {
printUsageAndExit();
}
}
if (outPath == null) {
System.err.println("file path must be specified.");
printUsageAndExit();
}
System.out.println("Random Spectrum Generator");
System.out.printf("outfile=%s probability=%f upper shift=%d lower shift=%d%n",
outPath, markovProbability, markovUpperShift, markovLowerShift
);
try (SeekableByteChannel channel = Files.newByteChannel(
outPath, StandardOpenOption.CREATE, StandardOpenOption.WRITE)
) {
ByteBuffer buffer = ByteBuffer.allocateDirect((int) (numSamples * 4 + 32));
buffer.order(ByteOrder.LITTLE_ENDIAN);
buffer.putLong(numSamples);
buffer.putDouble(startFrequency);
buffer.putDouble(stopFrequency);
buffer.putFloat(referenceLevel);
buffer.putFloat(scale);
int previous = 250;
for (int i = 0; i < numSamples; i++) {
int value = markov(markovProbability, previous, markovUpperShift, markovLowerShift);
previous = value;
buffer.putInt(value);
}
buffer.flip();
channel.write(buffer);
}
}
/**
* Generate the power value with specified probability, current power, shift values toward increasing and decreasing.
*
* @param p the probalility toward increasing power(0,1)
* @param previous current power[0,255]
* @param upperShift shift power toward increasing[1,16]
* @param lowerShift shift power toward decreasing[1,16]
* @return next power[0,255]
*/
static int markov(double p, int previous, int upperShift, int lowerShift) {
if (random.nextDouble() < p) {
return Math.max(0, previous - upperShift);
} else {
return Math.min(255, previous + lowerShift);
}
}
static void printUsageAndExit() {
System.out.println("Command line usage: -f <file> -p <probability> -u <upper shift> -l <lower shift>");
System.out.println("\tfile: spectrum data file to be generated");
System.out.println("\tprobability: of power increased (0.0 to 1.0) by markov model");
System.out.println("\tupper shift: amount of power increase in a step");
System.out.println("\tlower shift: amount of power decrease in a step");
System.exit(1);
}
}

他の形式にエクスポート: Unified diff