Java Number Round roundy(double a, double precision)

Description

Returns the closest double to the argument that is equal for at least a precision value.

License

Open Source License

Parameter

Parameter	Description
a	a <code>double</code> value.
precision	a <code>double</code> value setting the precision. The smaller the precision, the more precise, the number returned, the larger the less precise and rounded earlier. Precisions above 1 will even round the non-fractional part.

Return

(double) Math.round(a / precision) * precision.

Declaration

public static double roundy(double a, double precision) 

Method Source Code

//package com.java2s;

public class Main {
    /**/*from   w w  w. j  av a 2  s.  c o  m*/
     * The default tolerance for two numbers to be treated equal.
     * (experimental)
     * @see #setDefaultTolerance(double)
     * @invariants DefaultTolerance ≥ 0
     */
    private static double DefaultTolerance = .00000000001;

    /**
     * Returns the closest <code>double</code> to the argument that is equal for at least a precision value.
     * 
     * @param   a   a <code>double</code> value.
     * @param   precision   a <code>double</code> value setting the precision.
     * The smaller the precision, the more precise, the number returned,
     * the larger the less precise and rounded earlier.
     * Precisions above 1 will even round the non-fractional part.
     * @return (<span class="keyword">double</span>) <span class="Class">Math</span>.round(a <span class="operator">/</span> precision) <span class="operator">*</span> precision.
     */
    public static double roundy(double a, double precision) {
        return (double) Math.round(a / precision) * precision;
    }

    public static double roundy(double a) {
        return roundy(a, precisionFor(a));
    }

    /**
     * Returns the mathematically rounded part of a
     * <code>double</code> value.
     */
    public static int round(double a, int rounding_style) {
        throw new UnsupportedOperationException("not yet implemented");
    }

    /**
     * Get the precision for a given a specified tolerance relative to the magnitude of a.
     * <p>
     * Roughly gives the precision for tolerance percent of a, but adjusted to decimal digits.
     * </p>
     * @return tolerance * 10<sup>&lceil;&#13266;<sub>10</sub> a&rceil;</sup>.
     */
    public static double precisionFor(double a, double tolerance) {
        return tolerance * Math.pow(10, Math.ceil(Math.log(a) / Math.log(10)));
    }

    /**
     * Get the precision for a default tolerance relative to the magnitude of a.
     */
    public static double precisionFor(double a) {
        return precisionFor(a, DefaultTolerance);
    }
}

Related

1. roundValue(Double value)
2. roundValue(final double value)
3. roundValues(Double value1, Double value2)
4. roundValueToUnit(final double graphValue, final double graphUnit, final boolean isMinValue)
5. roundy(double a)