Package org.apfloat.internal
Class DoubleWTables
- java.lang.Object
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- org.apfloat.internal.DoubleElementaryModMath
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- org.apfloat.internal.DoubleModMath
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- org.apfloat.internal.DoubleWTables
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public class DoubleWTables extends DoubleModMath
Helper class for generating and caching tables of powers of the n:th root of unity.- Since:
- 1.7.0
- Version:
- 1.9.0
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Field Summary
Fields Modifier and Type Field Description private static java.util.concurrent.ConcurrentMap<java.util.List<java.lang.Integer>,double[]>
cache
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Constructor Summary
Constructors Modifier Constructor Description private
DoubleWTables()
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Method Summary
All Methods Static Methods Concrete Methods Modifier and Type Method Description private static DoubleModMath
getInstance(int modulus)
static double[]
getInverseWTable(int modulus, int length)
Get a table of inverses of powers of n:th root of unity.static double[]
getWTable(int modulus, int length)
Get a table of powers of n:th root of unity.private static double[]
getWTable(int modulus, int length, boolean isInverse)
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Methods inherited from class org.apfloat.internal.DoubleModMath
createWTable, getForwardNthRoot, getInverseNthRoot, modDivide, modInverse, modPow, negate
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Methods inherited from class org.apfloat.internal.DoubleElementaryModMath
getModulus, modAdd, modMultiply, modSubtract, setModulus
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Method Detail
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getWTable
public static double[] getWTable(int modulus, int length)
Get a table of powers of n:th root of unity.- Parameters:
modulus
- The index of the modulus to be used.length
- The length of the table to be returned, i.e. n.- Returns:
- The table of powers of the n:th root of unity.
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getInverseWTable
public static double[] getInverseWTable(int modulus, int length)
Get a table of inverses of powers of n:th root of unity.- Parameters:
modulus
- The index of the modulus to be used.length
- The length of the table to be returned, i.e. n.- Returns:
- The table of inverses of powers of the n:th root of unity.
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getWTable
private static double[] getWTable(int modulus, int length, boolean isInverse)
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getInstance
private static DoubleModMath getInstance(int modulus)
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