Class MedianExperimentor

Synopsis of Class MedianExperimentor

public class MedianExperimentor { 
    /*
     * Forge (1)
     */
        MedianExperimentor(); 
    /*
     * Utilities (4)
     */
        static void main(String[] args) throws IOException; 
        static final int MAX_N; 
        static void addPowers(Set<Integer> ns, int base); 
        static int pow(int b, int e); 
} 

Input types: Set.

Exception types: IOException.

Code

// SSDLPedia
package il.ac.technion.cs.cs236700.median;

import static il.ac.technion.cs.ssdl.utils.DBC.nonnull;
import static il.ac.technion.cs.ssdl.utils.DBC.positive;
import il.ac.technion.cs.ssdl.csv.CSVLine;
import il.ac.technion.cs.ssdl.csv.CSVWriter;
import il.ac.technion.cs.ssdl.stereotypes.Application;
import il.ac.technion.cs.ssdl.utils.Permutation;
import il.ac.technion.cs.ssdl.utils.Statistics;

import java.io.IOException;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

@Application public class MedianExperimentor {
    public static void main(final String[] args) throws IOException {
        final CSVWriter w = new CSVWriter("median.csv");
        for (final int n : selectRange()) {
            System.out.println("Computing median of arrays sized " + n);
            for (final ApproximateMedian a : ApproximateMedian.$$$)
                w.writeflush(exerciseManyMedian(n, a));
        }
        w.close();
    }
    
    static final int REPETITIONS = 100;
    
    private static CSVLine exerciseManyMedian(final int n, final ApproximateMedian a) {
        positive(n);
        nonnull(a);
        final Statistics s = new Statistics();
        for (int i = 0; i < REPETITIONS; i++)
            s.record(exerciseOneMedian(n, a));
        final CSVLine $ = new CSVLine.Ordered();
        $.put("N", n);
        $.put("EXPERIMENTS", s.n());
        $.put("ALGORITHM", a.getClass().getSimpleName());
        $.put("AVERAGE_MEDIAN", s.mean());
        $.put("AVERAGE RELATIVE MEDIAN", s.mean() / n);
        $.put("SD", s.sd());
        $.put("RELATIVE SD", s.sd() / n);
        $.put("RELATIVE LOG SD", log(s.sd(), n));
        return $;
    }
    
    private static double log(final double b, final double d) {
        positive(b);
        positive(d);
        return Math.log(d) / Math.log(b);
    }
    
    private static int exerciseOneMedian(final int n, final ApproximateMedian a) {
        return a.value(Permutation.random(n));
    }
    
    public static final int MAX_N = pow(10, 6);
    
    private static int[] selectRange() {
        final Set<Integer> $ = new HashSet<Integer>();
        final int[] bases = new int[] { 2, 3, 5, 7 };
        for (final int b : bases)
            addPowers($, b);
        return toArray($);
    }
    
    private static int[] toArray(final Set<Integer> is) {
        final int[] $ = new int[is.size()];
        int i = 0;
        for (final Integer v : is)
            $[i++] = v.intValue();
        Arrays.sort($);
        return $;
    }
    
    public static void addPowers(final Set<Integer> ns, final int base) {
        for (int i = 0;; i++) {
            final int n = pow(base, i);
            if (n > MAX_N)
                return;
            ns.add(new Integer(n));
        }
    }
    
    public static int pow(final int b, final int e) {
        if (e == 0)
            return 1;
        final int $ = pow(b * b, e / 2);
        return e % 2 == 0 ? $ : $ * b;
    }
}

Metrics

Metric	Value	Acronym	Explanation
LOC	93	Lines Of Code	Total number of lines in the code
SCC	55	SemiColons Count	Total number of semicolon tokens found in the code.
NOT	755	Number Of Tokens	Comments, whitespace and text which cannot be made into a token not included.
VCC	2180	Visible Characters Count	The total number of non-white (i.e., not space, tab, newline, carriage return, form feed) characters.
CCC	2107	Code Characters Count	Total number of non-white characters in tokens. White space characters in string and character literals are not counted.
UIC	74	Unique Identifiers Count	The number of different identifiers found in the code
WHC	4	Weighted Horizontal Complexity	A heuritistic on horizontal complexity

Statistics

Statistic	Value
Average token length	2.8
Tokens/line	8.1
Visible characters/line	23
Code characters/line	23
Semicolons/tokens	7%
Comment text percentage	3%

Tokens by Kind

Token Kind	Occurrences
KEYWORD	112
OPERATOR	38
LITERAL	25
ID	245
PUNCTUATION	335
COMMENT	1
OTHER	306