Example usage for org.apache.commons.math4.util FastMath abs

Introduction

In this page you can find the example usage for org.apache.commons.math4.util FastMath abs.

Prototype

public static double abs(double x) 

Source Link

Document

Absolute value.

Usage

From source file:com.ericbarnhill.arrayMath.ArrayMath.java

/**
  * In-place element-wise {@code abs} of a {@code double[]}. Returns reference to first passed array.
  */*from w  ww.jav  a  2 s  . c  o m*/
  * @param f {@code double[]} array.
  * @return  {@code double[]} array.
  * 
  * @since 0.1
  */
public static double[] abs(double[] f) {
    final int fi = f.length;
    for (int i = 0; i < fi; i++) {
        f[i] = FastMath.abs(f[i]);
    }
    return f;
}

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From source file:RealFunctionValidation.java

public static SummaryStatistics assessAccuracy(final Method method, final DataInputStream in,
        final DataOutputStream out)
        throws IOException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {

    if (method.getReturnType() != Double.TYPE) {
        throw new IllegalArgumentException("method must return a double");
    }//from   w ww  .  j  a v a2 s.c o m

    final Class<?>[] types = method.getParameterTypes();
    for (int i = 0; i < types.length; i++) {
        if (!types[i].isPrimitive()) {
            final StringBuilder builder = new StringBuilder();
            builder.append("argument #").append(i + 1).append(" of method ").append(method.getName())
                    .append("must be of primitive of type");
            throw new IllegalArgumentException(builder.toString());
        }
    }

    final SummaryStatistics stat = new SummaryStatistics();
    final Object[] parameters = new Object[types.length];
    while (true) {
        try {
            for (int i = 0; i < parameters.length; i++) {
                parameters[i] = readAndWritePrimitiveValue(in, out, types[i]);
            }
            final double expected = in.readDouble();
            if (FastMath.abs(expected) > 1E-16) {
                final Object value = method.invoke(null, parameters);
                final double actual = ((Double) value).doubleValue();
                final double err = FastMath.abs(actual - expected);
                final double ulps = err / FastMath.ulp(expected);
                out.writeDouble(expected);
                out.writeDouble(actual);
                out.writeDouble(ulps);
                stat.addValue(ulps);
            }
        } catch (EOFException e) {
            break;
        }
    }
    return stat;
}

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From source file:com.ericbarnhill.arrayMath.ArrayMath.java

/**
  * Element-wise {@code abs} of a {@code double[]}. Returns deep copy.
  *// ww w .  ja  va 2  s  .  com
  * @param f {@code double[]} array.
  * @return  {@code double[]} array.
  * 
  * @since 0.1
  */
public static double[] absC(double[] f) {
    final int fi = f.length;
    double[] h = new double[fi];
    for (int i = 0; i < fi; i++) {
        h[i] = FastMath.abs(f[i]);
    }
    return h;
}

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