/* Imported from Mahout. */package org.carrot2.mahout.math.function;
public final class Functions {
/*
* <H3>Unary functions</H3>
*/
public static final DoubleFunction ABS = new DoubleFunction() {
@Override
public double apply(double a) {
return Math.abs(a);
}
};
public static final DoubleFunction ACOS = new DoubleFunction() {
@Override
public double apply(double a) {
return Math.acos(a);
}
};
public static final DoubleFunction ASIN = new DoubleFunction() {
@Override
public double apply(double a) {
return Math.asin(a);
}
};
public static final DoubleFunction ATAN = new DoubleFunction() {
@Override
public double apply(double a) {
return Math.atan(a);
}
};
public static final DoubleFunction CEIL = new DoubleFunction() {
@Override
public double apply(double a) {
return Math.ceil(a);
}
};
public static final DoubleFunction COS = new DoubleFunction() {
@Override
public double apply(double a) {
return Math.cos(a);
}
};
public static final DoubleFunction EXP = new DoubleFunction() {
@Override
public double apply(double a) {
return Math.exp(a);
}
};
public static final DoubleFunction FLOOR = new DoubleFunction() {
@Override
public double apply(double a) {
return Math.floor(a);
}
};
public static final DoubleFunction IDENTITY = new DoubleFunction() {
@Override
public double apply(double a) {
return a;
}
};
public static final DoubleFunction INV = new DoubleFunction() {
@Override
public double apply(double a) {
return 1.0 / a;
}
};
public static final DoubleFunction LOGARITHM = new DoubleFunction() {
@Override
public double apply(double a) {
return Math.log(a);
}
};
public static final DoubleFunction LOG2 = new DoubleFunction() {
@Override
public double apply(double a) {
return Math.log(a) * 1.4426950408889634;
}
};
public static final DoubleFunction NEGATE = new DoubleFunction() {
@Override
public double apply(double a) {
return -a;
}
};
public static final DoubleFunction RINT = new DoubleFunction() {
@Override
public double apply(double a) {
return Math.rint(a);
}
};
public static final DoubleFunction SIGN = new DoubleFunction() {
@Override
public double apply(double a) {
return a < 0 ? -1 : a > 0 ? 1 : 0;
}
};
public static final DoubleFunction SIN = new DoubleFunction() {
@Override
public double apply(double a) {
return Math.sin(a);
}
};
public static final DoubleFunction SQRT = new DoubleFunction() {
@Override
public double apply(double a) {
return Math.sqrt(a);
}
};
public static final DoubleFunction SQUARE = new DoubleFunction() {
@Override
public double apply(double a) {
return a * a;
}
};
public static final DoubleFunction SIGMOID = new DoubleFunction() {
@Override
public double apply(double a) {
return 1.0 / (1.0 + Math.exp(-a));
}
};
public static final DoubleFunction SIGMOIDGRADIENT = new DoubleFunction() {
@Override
public double apply(double a) {
return a * (1.0 - a);
}
};
public static final DoubleFunction TAN = new DoubleFunction() {
@Override
public double apply(double a) {
return Math.tan(a);
}
};
/*
* <H3>Binary functions</H3>
*/
public static final DoubleDoubleFunction ATAN2 = new DoubleDoubleFunction() {
@Override
public double apply(double a, double b) {
return Math.atan2(a, b);
}
};
public static final DoubleDoubleFunction COMPARE = new DoubleDoubleFunction() {
@Override
public double apply(double a, double b) {
return a < b ? -1 : a > b ? 1 : 0;
}
};
public static final DoubleDoubleFunction DIV = new DoubleDoubleFunction() {
@Override
public double apply(double a, double b) {
return a / b;
}
};
public static final DoubleDoubleFunction EQUALS = new DoubleDoubleFunction() {
@Override
public double apply(double a, double b) {
return a == b ? 1 : 0;
}
};
public static final DoubleDoubleFunction GREATER = new DoubleDoubleFunction() {
@Override
public double apply(double a, double b) {
return a > b ? 1 : 0;
}
};
public static final DoubleDoubleFunction IEEE_REMAINDER = new DoubleDoubleFunction() {
@Override
public double apply(double a, double b) {
return Math.IEEEremainder(a, b);
}
};
public static final DoubleDoubleFunction LESS = new DoubleDoubleFunction() {
@Override
public double apply(double a, double b) {
return a < b ? 1 : 0;
}
};
public static final DoubleDoubleFunction LG = new DoubleDoubleFunction() {
@Override
public double apply(double a, double b) {
return Math.log(a) / Math.log(b);
}
};
public static final DoubleDoubleFunction MAX = new DoubleDoubleFunction() {
@Override
public double apply(double a, double b) {
return Math.max(a, b);
}
};
public static final DoubleDoubleFunction MIN = new DoubleDoubleFunction() {
@Override
public double apply(double a, double b) {
return Math.min(a, b);
}
};
public static final DoubleDoubleFunction MINUS = plusMult(-1);
/*
new DoubleDoubleFunction() {
public final double apply(double a, double b) { return a - b; }
};
*/
public static final DoubleDoubleFunction MOD = new DoubleDoubleFunction() {
@Override
public double apply(double a, double b) {
return a % b;
}
};
public static final DoubleDoubleFunction MULT = new DoubleDoubleFunction() {
@Override
public double apply(double a, double b) {
return a * b;
}
};
public static final DoubleDoubleFunction PLUS = new DoubleDoubleFunction() {
@Override
public double apply(double a, double b) {
return a + b;
}
};
public static final DoubleDoubleFunction PLUS_ABS = new DoubleDoubleFunction() {
@Override
public double apply(double a, double b) {
return Math.abs(a) + Math.abs(b);
}
};
public static final DoubleDoubleFunction POW = new DoubleDoubleFunction() {
@Override
public double apply(double a, double b) {
return Math.pow(a, b);
}
};
private Functions() {
}
public static DoubleFunction between(final double from, final double to) {
return new DoubleFunction() {
@Override
public double apply(double a) {
return from <= a && a <= to ? 1 : 0;
}
};
}
public static DoubleFunction bindArg1(final DoubleDoubleFunction function, final double c) {
return new DoubleFunction() {
@Override
public double apply(double var) {
return function.apply(c, var);
}
};
}
public static DoubleFunction bindArg2(final DoubleDoubleFunction function, final double c) {
return new DoubleFunction() {
@Override
public double apply(double var) {
return function.apply(var, c);
}
};
}
public static DoubleDoubleFunction chain(final DoubleDoubleFunction f, final DoubleFunction g,
final DoubleFunction h) {
return new DoubleDoubleFunction() {
@Override
public double apply(double a, double b) {
return f.apply(g.apply(a), h.apply(b));
}
};
}
public static DoubleDoubleFunction chain(final DoubleFunction g, final DoubleDoubleFunction h) {
return new DoubleDoubleFunction() {
@Override
public double apply(double a, double b) {
return g.apply(h.apply(a, b));
}
};
}
public static DoubleFunction chain(final DoubleFunction g, final DoubleFunction h) {
return new DoubleFunction() {
@Override
public double apply(double a) {
return g.apply(h.apply(a));
}
};
}
public static DoubleFunction compare(final double b) {
return new DoubleFunction() {
@Override
public double apply(double a) {
return a < b ? -1 : a > b ? 1 : 0;
}
};
}
public static DoubleFunction constant(final double c) {
return new DoubleFunction() {
@Override
public double apply(double a) {
return c;
}
};
}
public static DoubleFunction div(double b) {
return mult(1 / b);
}
public static DoubleFunction equals(final double b) {
return new DoubleFunction() {
@Override
public double apply(double a) {
return a == b ? 1 : 0;
}
};
}
public static DoubleFunction greater(final double b) {
return new DoubleFunction() {
@Override
public double apply(double a) {
return a > b ? 1 : 0;
}
};
}
public static DoubleFunction mathIEEEremainder(final double b) {
return new DoubleFunction() {
@Override
public double apply(double a) {
return Math.IEEEremainder(a, b);
}
};
}
public static DoubleFunction less(final double b) {
return new DoubleFunction() {
@Override
public double apply(double a) {
return a < b ? 1 : 0;
}
};
}
public static DoubleFunction lg(final double b) {
return new DoubleFunction() {
private final double logInv = 1 / Math.log(b); // cached for speed
@Override
public double apply(double a) {
return Math.log(a) * logInv;
}
};
}
public static DoubleFunction max(final double b) {
return new DoubleFunction() {
@Override
public double apply(double a) {
return Math.max(a, b);
}
};
}
public static DoubleFunction min(final double b) {
return new DoubleFunction() {
@Override
public double apply(double a) {
return Math.min(a, b);
}
};
}
public static DoubleFunction minus(double b) {
return plus(-b);
}
public static DoubleDoubleFunction minusMult(double constant) {
return plusMult(-constant);
}
public static DoubleFunction mod(final double b) {
return new DoubleFunction() {
@Override
public double apply(double a) {
return a % b;
}
};
}
public static DoubleFunction mult(double b) {
return new Mult(b);
/*
return new DoubleFunction() {
public final double apply(double a) { return a * b; }
};
*/
}
public static DoubleFunction plus(final double b) {
return new DoubleFunction() {
@Override
public double apply(double a) {
return a + b;
}
};
}
public static DoubleDoubleFunction plusMult(double constant) {
return new PlusMult(constant);
/*
return new DoubleDoubleFunction() {
public final double apply(double a, double b) { return a + b*constant; }
};
*/
}
public static DoubleFunction pow(final double b) {
return new DoubleFunction() {
@Override
public double apply(double a) {
return Math.pow(a, b);
}
};
}
public static DoubleFunction round(final double precision) {
return new DoubleFunction() {
@Override
public double apply(double a) {
return Math.rint(a / precision) * precision;
}
};
}
public static DoubleDoubleFunction swapArgs(final DoubleDoubleFunction function) {
return new DoubleDoubleFunction() {
@Override
public double apply(double a, double b) {
return function.apply(b, a);
}
};
}
}