List of usage examples for java.lang Math log
@HotSpotIntrinsicCandidate public static double log(double a)
From source file:Main.java
public static Bitmap decodeFile(File theFile, int IMAGE_MAX_SIZE) { Bitmap bmp = null;// www . j a v a 2 s.c o m try { // Decode image size BitmapFactory.Options o = new BitmapFactory.Options(); o.inJustDecodeBounds = true; FileInputStream fis = new FileInputStream(theFile); BitmapFactory.decodeStream(fis, null, o); fis.close(); int scale = 1; if (o.outHeight > IMAGE_MAX_SIZE || o.outWidth > IMAGE_MAX_SIZE) { scale = (int) Math.pow(2, (int) Math.round( Math.log(IMAGE_MAX_SIZE / (double) Math.max(o.outHeight, o.outWidth)) / Math.log(0.5))); } // Decode with inSampleSize BitmapFactory.Options o2 = new BitmapFactory.Options(); o2.inSampleSize = scale; fis = new FileInputStream(theFile); bmp = BitmapFactory.decodeStream(fis, null, o2); fis.close(); } catch (IOException e) { } return bmp; }
From source file:com.maskyn.fileeditorpro.util.AccessStorageApi.java
public static Bitmap loadPrescaledBitmap(String filename) throws IOException { // Facebook image size final int IMAGE_MAX_SIZE = 630; File file = null;/* w ww. jav a2 s. c o m*/ FileInputStream fis; BitmapFactory.Options opts; int resizeScale; Bitmap bmp; file = new File(filename); // This bit determines only the width/height of the bitmap without loading the contents opts = new BitmapFactory.Options(); opts.inJustDecodeBounds = true; fis = new FileInputStream(file); BitmapFactory.decodeStream(fis, null, opts); fis.close(); // Find the correct scale value. It should be a power of 2 resizeScale = 1; if (opts.outHeight > IMAGE_MAX_SIZE || opts.outWidth > IMAGE_MAX_SIZE) { resizeScale = (int) Math.pow(2, (int) Math.round( Math.log(IMAGE_MAX_SIZE / (double) Math.max(opts.outHeight, opts.outWidth)) / Math.log(0.5))); } // Load pre-scaled bitmap opts = new BitmapFactory.Options(); opts.inSampleSize = resizeScale; fis = new FileInputStream(file); bmp = BitmapFactory.decodeStream(fis, null, opts); fis.close(); return bmp; }
From source file:edu.byu.nlp.stats.UniformDistribution.java
/** {@inheritDoc} */ @Override public double entropy() { return Math.log(numLabels); }
From source file:emlab.util.GeometricTrendRegression.java
public void addData(double[][] data) { for (int i = 0; i < data.length; i++) { addData(data[i][0], Math.log(data[i][1])); }//from w w w . ja v a2 s . co m }
From source file:ldbc.snb.datagen.generator.distribution.utils.Bucket.java
public static ArrayList<Bucket> bucketizeHistogram(ArrayList<Pair<Integer, Integer>> histogram, int num_buckets) { ArrayList<Bucket> buckets = new ArrayList<Bucket>(); int population = 0; int num_edges = 0; for (Pair<Integer, Integer> i : histogram) { population += i.getValue();/*from ww w . j a va 2 s. c o m*/ num_edges += i.getValue() * i.getKey(); } num_edges /= 2; int avgDegreeAt1B = 200; int avgDegree = num_edges / population; double aCoeff = Math.log(avgDegreeAt1B) / Math.log(1000000000); double bCoeff = (aCoeff - (Math.log(avgDegree) / Math.log(population))) / Math.log10(population); int target_mean = (int) Math.round( Math.pow(DatagenParams.numPersons, (aCoeff - bCoeff * Math.log10(DatagenParams.numPersons)))); System.out.println("Distribution mean degree: " + avgDegree + " Distribution target mean " + target_mean); int bucket_size = (int) (Math.ceil(population / (double) (num_buckets))); int current_histogram_index = 0; int current_histogram_left = histogram.get(current_histogram_index).getValue(); for (int i = 0; i < num_buckets && (current_histogram_index < histogram.size()); ++i) { int current_bucket_count = 0; int min = population; int max = 0; while (current_bucket_count < bucket_size && current_histogram_index < histogram.size()) { int degree = histogram.get(current_histogram_index).getKey(); min = degree < min ? degree : min; max = degree > max ? degree : max; if ((bucket_size - current_bucket_count) > current_histogram_left) { current_bucket_count += current_histogram_left; current_histogram_index++; if (current_histogram_index < histogram.size()) { current_histogram_left = histogram.get(current_histogram_index).getValue(); } } else { current_histogram_left -= (bucket_size - current_bucket_count); current_bucket_count = bucket_size; } } min = (int) (min * target_mean / (double) avgDegree); max = (int) (max * target_mean / (double) avgDegree); buckets.add(new Bucket(min, max)); } return buckets; }
From source file:io.seldon.vw.VwFeatureHash.java
private double log2(int val, int base) { return Math.log(val) / Math.log(base); }
From source file:com.opengamma.analytics.financial.interestrate.market.MarketDiscountingTimeDecorated.java
@Override public double getDiscountingFactor(Currency ccy, Double time) { if ((ccy == _ccy) && (_time == time)) { double rate = -Math.log(super.getDiscountingFactor(ccy, time)) / time; return Math.exp(-(rate + _shift) * time); }// ww w.j a va2s. c o m return super.getDiscountingFactor(ccy, time); }
From source file:geogebra.util.MyMath.java
final public static double atanh(double a) { return Math.log((1.0 + a) / (1.0 - a)) * 0.5; }
From source file:beast.math.distributions.NegativeBinomialDistribution.java
public double logPdf(double x) { if (x < 0) return Double.NEGATIVE_INFINITY; double r = -1 * (mean * mean) / (mean - stdev * stdev); double p = mean / (stdev * stdev); return Math.log(Math.pow(1 - p, x)) + Math.log(Math.pow(p, r)) + GammaFunction.lnGamma(r + x) - GammaFunction.lnGamma(r) - GammaFunction.lnGamma(x + 1); }
From source file:com.opengamma.analytics.financial.interestrate.market.description.MarketDiscountingTimeDecorated.java
@Override public double getDiscountFactor(Currency ccy, Double time) { if ((ccy == _ccy) && (_time == time)) { double rate = -Math.log(super.getDiscountFactor(ccy, time)) / time; return Math.exp(-(rate + _shift) * time); }//from w w w .ja v a2 s . c o m return super.getDiscountFactor(ccy, time); }