Le 23/01/2011 01:58, s...@apache.org a écrit : > Author: sebb > Date: Sun Jan 23 00:58:07 2011 > New Revision: 1062304 > > URL: http://svn.apache.org/viewvc?rev=1062304&view=rev > Log: > MATH-496 Create FastMath copySign methods
I was also creating these methods. I have created all the missing ones and implemented hypot directly, so don't bother doing it too. Luc > > Modified: > > commons/proper/math/branches/MATH_2_X/src/main/java/org/apache/commons/math/util/FastMath.java > > Modified: > commons/proper/math/branches/MATH_2_X/src/main/java/org/apache/commons/math/util/FastMath.java > URL: > http://svn.apache.org/viewvc/commons/proper/math/branches/MATH_2_X/src/main/java/org/apache/commons/math/util/FastMath.java?rev=1062304&r1=1062303&r2=1062304&view=diff > ============================================================================== > --- > commons/proper/math/branches/MATH_2_X/src/main/java/org/apache/commons/math/util/FastMath.java > (original) > +++ > commons/proper/math/branches/MATH_2_X/src/main/java/org/apache/commons/math/util/FastMath.java > Sun Jan 23 00:58:07 2011 > @@ -247,18 +247,6 @@ public class FastMath { > // Generic helper methods > > /** > - * Get the sign information (works even for 0). > - * > - * @param d the value to check > - * > - * @return +1.0 or -1.0, never 0.0 > - */ > - private static double getSign(double d){ // TODO perhaps move to > MathUtils? > - long l = Double.doubleToLongBits(d); > - return l < 0 ? -1.0 : 1.0; > - } > - > - /** > * Get the high order bits from the mantissa. > * Equivalent to adding and subtracting HEX_40000 but also works for > very large numbers > * > @@ -2798,7 +2786,7 @@ public class FastMath { > int idx; > > if (xa == 0.0) { // Matches +/- 0.0; return correct sign > - return leftPlane ? getSign(xa) * Math.PI : xa; > + return leftPlane ? copySign(Math.PI, xa) : xa; > } > > if (xa < 0) { > @@ -2957,7 +2945,7 @@ public class FastMath { > if (x > 0) { > return y; // return +/- 0.0 > } else { > - return getSign(y) * Math.PI; > + return copySign(Math.PI, y); > } > } > > @@ -3737,4 +3725,37 @@ public class FastMath { > return StrictMath.IEEEremainder(dividend, divisor); // TODO provide > our own implementation > } > > + /** > + * Returns the first argument with the sign of the second argument. > + * A NaN {@code sign} argument is treated as positive. > + * > + * @param magnitude the value to return > + * @param sign the sign for the returned value > + * @return the magnitude with the same sign as the {@code sign} argument > + */ > + public static double copySign(double magnitude, double sign){ > + long m = Double.doubleToLongBits(magnitude); > + long s = Double.doubleToLongBits(sign); > + if ((m >= 0 && s >= 0) || (m < 0 && s < 0)) { // Sign is currently OK > + return magnitude; > + } > + return -magnitude; // flip sign > + } > + > + /** > + * Returns the first argument with the sign of the second argument. > + * A NaN {@code sign} argument is treated as positive. > + * > + * @param magnitude the value to return > + * @param sign the sign for the returned value > + * @return the magnitude with the same sign as the {@code sign} argument > + */ > + public static float copySign(float magnitude, float sign){ > + int m = Float.floatToIntBits(magnitude); > + int s = Float.floatToIntBits(sign); > + if ((m >= 0 && s >= 0) || (m < 0 && s < 0)) { // Sign is currently OK > + return magnitude; > + } > + return -magnitude; // flip sign > + } > } > > > --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org For additional commands, e-mail: dev-h...@commons.apache.org
