sascha@655: package de.intevation.flys.utils;
sascha@655:
sascha@3776: import de.intevation.flys.artifacts.math.Linear;
sascha@3776:
sascha@3776: import gnu.trove.TDoubleArrayList;
sascha@3776:
ingo@1666: import java.util.Arrays;
ingo@1666:
sascha@3776: import org.apache.log4j.Logger;
ingo@1666:
felix@4052: /** Utils to deal with Double precision values. */
sascha@655: public class DoubleUtil
sascha@655: {
felix@4052: /** Private logger. */
sascha@3776: private static Logger log = Logger.getLogger(DoubleUtil.class);
sascha@3776:
sascha@655: public static final double DEFAULT_STEP_PRECISION = 1e6;
sascha@655:
sascha@655: private DoubleUtil() {
sascha@655: }
sascha@655:
sascha@655: public static final double [] explode(double from, double to, double step) {
sascha@655: return explode(from, to, step, DEFAULT_STEP_PRECISION);
sascha@655: }
sascha@655:
sascha@655: public static final double round(double x, double precision) {
sascha@655: return Math.round(x * precision)/precision;
sascha@655: }
sascha@655:
sascha@655: public static final double round(double x) {
sascha@655: return Math.round(x * DEFAULT_STEP_PRECISION)/DEFAULT_STEP_PRECISION;
sascha@655: }
sascha@655:
sascha@655: public static final double [] explode(
sascha@655: double from,
sascha@655: double to,
sascha@655: double step,
sascha@655: double precision
sascha@655: ) {
sascha@655: double lower = from;
sascha@655:
sascha@655: double diff = to - from;
sascha@655: double tmp = diff / step;
sascha@655: int num = (int)Math.abs(Math.ceil(tmp)) + 1;
sascha@655:
teichmann@4163: if (num < 1) {
teichmann@4163: return new double[0];
teichmann@4163: }
teichmann@4163:
sascha@655: double [] values = new double[num];
sascha@655:
sascha@655: if (from > to) {
sascha@655: step = -step;
sascha@655: }
sascha@655:
ingo@1666: double max = Math.max(from, to);
ingo@1666:
sascha@655: for (int idx = 0; idx < num; idx++) {
ingo@1666: if (lower > max) {
ingo@1666: return Arrays.copyOfRange(values, 0, idx);
ingo@1666: }
ingo@1666:
sascha@655: values[idx] = round(lower, precision);
sascha@655: lower += step;
sascha@655: }
sascha@655:
sascha@655: return values;
sascha@655: }
sascha@1671:
sascha@1671: public static final double interpolateSorted(
sascha@1671: double [] xs,
sascha@1671: double [] ys,
sascha@1671: double x
sascha@1671: ) {
sascha@1671: int lo = 0, hi = xs.length-1;
sascha@1671:
sascha@1671: int mid = -1;
sascha@1671:
sascha@1671: while (lo <= hi) {
sascha@1671: mid = (lo + hi) >> 1;
sascha@1671: double mx = xs[mid];
sascha@1671: if (x < mx) hi = mid - 1;
sascha@1671: else if (x > mx) lo = mid + 1;
sascha@1671: else return ys[mid];
sascha@1671: }
sascha@1671: if (mid < lo) {
sascha@1671: return lo >= xs.length
sascha@1671: ? Double.NaN
sascha@1671: : Linear.linear(x, xs[mid], xs[mid+1], ys[mid], ys[mid+1]);
sascha@1671: }
sascha@1671: return hi < 0
sascha@1671: ? Double.NaN
sascha@1671: : Linear.linear(x, xs[mid-1], xs[mid], ys[mid-1], ys[mid]);
sascha@1671: }
sascha@1672:
sascha@1672: public static final boolean isIncreasing(double [] array) {
sascha@1672: int inc = 0;
sascha@1672: int dec = 0;
sascha@1672: int sweet = (array.length-1)/2;
sascha@1672: for (int i = 1; i < array.length; ++i) {
sascha@1672: if (array[i] > array[i-1]) {
sascha@1672: if (++inc > sweet) {
sascha@1672: return true;
sascha@1672: }
sascha@1672: }
sascha@1672: else if (++dec > sweet) {
sascha@1672: return false;
sascha@1672: }
sascha@1672: }
sascha@1672: return inc > sweet;
sascha@1672: }
sascha@1672:
sascha@1672: public static final double [] swap(double [] array) {
sascha@1672: int lo = 0;
sascha@1672: int hi = array.length-1;
sascha@1672: while (hi > lo) {
sascha@1672: double t = array[lo];
sascha@1672: array[lo] = array[hi];
sascha@1672: array[hi] = t;
sascha@1672: ++lo;
sascha@1672: --hi;
sascha@1672: }
sascha@1672:
sascha@1672: return array;
sascha@1672: }
sascha@1672:
sascha@1672: public static final double [] swapClone(double [] in) {
sascha@1672: double [] out = new double[in.length];
sascha@1672:
sascha@1672: for (int j = out.length-1, i = 0; j >= 0;) {
sascha@1672: out[j--] = in[i++];
sascha@1672: }
sascha@1672:
sascha@1672: return out;
sascha@1672: }
sascha@1672:
sascha@1672: public static final double [] sumDiffs(double [] in) {
sascha@1672: double [] out = new double[in.length];
sascha@1672:
sascha@1672: for (int i = 1; i < out.length; ++i) {
sascha@1672: out[i] = out[i-1] + Math.abs(in[i-1] - in[i]);
sascha@1672: }
sascha@1672:
sascha@1672: return out;
sascha@1672: }
sascha@2569:
sascha@2569: public static final double [] fill(int N, double value) {
sascha@2569: double [] result = new double[N];
sascha@2569: Arrays.fill(result, value);
sascha@2569: return result;
sascha@2569: }
sascha@3776:
felix@4052:
felix@4052: /** Use with parseSegments. */
sascha@3776: public interface SegmentCallback {
sascha@3776: void newSegment(double from, double to, double [] values);
sascha@3776: }
sascha@3776:
felix@4052:
felix@4052: /** Call callback for every string split by colon.
felix@4433: * Expected format FROM:TO:VALUE1,VALUE2,VALUE3*/
sascha@3776: public static final void parseSegments(
sascha@3776: String input,
sascha@3776: SegmentCallback callback
sascha@3776: ) {
sascha@3776: TDoubleArrayList vs = new TDoubleArrayList();
sascha@3776:
sascha@3776: for (String segmentStr: input.split(":")) {
sascha@3776: String [] parts = segmentStr.split(";");
sascha@3776: if (parts.length < 3) {
sascha@3776: log.warn("invalid segment: '" + segmentStr + "'");
sascha@3776: continue;
sascha@3776: }
sascha@3776: try {
sascha@3776: double from = Double.parseDouble(parts[0].trim());
sascha@3776: double to = Double.parseDouble(parts[1].trim());
sascha@3776:
sascha@3776: vs.resetQuick();
sascha@3776:
sascha@3776: for (String valueStr: parts[2].split(",")) {
sascha@3776: vs.add(round(Double.parseDouble(valueStr.trim())));
sascha@3776: }
sascha@3776:
sascha@3776: callback.newSegment(from, to, vs.toNativeArray());
sascha@3776: }
sascha@3776: catch (NumberFormatException nfe) {
sascha@3776: log.warn("invalid segment: '" + segmentStr + "'");
sascha@3776: }
sascha@3776: }
sascha@3776: }
ingo@3785:
ingo@3785: public static final boolean isValid(double [][] data) {
ingo@3785: for (double [] ds: data) {
ingo@3785: for (double d: ds) {
ingo@3785: if (Double.isNaN(d)) {
ingo@3785: return false;
ingo@3785: }
ingo@3785: }
ingo@3785: }
ingo@3785: return true;
ingo@3785: }
felix@4340:
felix@4340:
felix@4340: /** In an array of doubles, search and return the maximum value. */
felix@4340: public static final double maxInArray(double[] values) {
felix@4340: double max = - Double.MAX_VALUE;
felix@4340: for (double d: values) {
felix@4340: if (d > max) max = d;
felix@4340: }
felix@4340: return max;
felix@4340: }
sascha@655: }
sascha@655: // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :