Package org.apfloat.internal
Class FloatModMath
java.lang.Object
org.apfloat.internal.FloatElementaryModMath
org.apfloat.internal.FloatModMath
- Direct Known Subclasses:
FloatFactor3NTTStepStrategy
,FloatNTTConvolutionStepStrategy
,FloatTableFNT
,FloatWTables
Modulo arithmetic functions for
float
data.- Version:
- 1.0
- Author:
- Mikko Tommila
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionfloat[]
createWTable(float w, int n)
Create a table of powers of n:th root of unity.float
getForwardNthRoot(float primitiveRoot, long n)
Get forward n:th root of unity.float
getInverseNthRoot(float primitiveRoot, long n)
Get inverse n:th root of unity.float
modDivide(float a, float b)
Modular division.float
modInverse(float a)
Modular inverse, that is1 / a
.float
modPow(float a, float n)
Modular power.float
negate(float a)
Modular negation.Methods inherited from class org.apfloat.internal.FloatElementaryModMath
getModulus, modAdd, modMultiply, modSubtract, setModulus
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Constructor Details
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FloatModMath
public FloatModMath()Default constructor.
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Method Details
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createWTable
public final float[] createWTable(float w, int n)Create a table of powers of n:th root of unity.- Parameters:
w
- The n:th root of unity modulo the current modulus.n
- The table length (= transform length).- Returns:
- Table of
table[i]=wi mod m
, i = 0, ..., n-1.
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getForwardNthRoot
public float getForwardNthRoot(float primitiveRoot, long n)Get forward n:th root of unity. This isw
.Assumes that the modulus is prime.
- Parameters:
primitiveRoot
- Primitive root of the modulus.n
- The transform length.- Returns:
- Forward n:th root of unity.
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getInverseNthRoot
public float getInverseNthRoot(float primitiveRoot, long n)Get inverse n:th root of unity. This isw-1
.Assumes that the modulus is prime.
- Parameters:
primitiveRoot
- Primitive root of the modulus.n
- The transform length.- Returns:
- Inverse n:th root of unity.
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modInverse
public final float modInverse(float a)Modular inverse, that is1 / a
. Assumes that the modulus is prime.- Parameters:
a
- The operand.- Returns:
a-1 mod m
.
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modDivide
public final float modDivide(float a, float b)Modular division. Assumes that the modulus is prime.- Parameters:
a
- The dividend.b
- The divisor.- Returns:
a*b-1 mod m
.
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negate
public final float negate(float a)Modular negation.- Parameters:
a
- The argument.- Returns:
-a mod m
.
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modPow
public final float modPow(float a, float n)Modular power. Assumes that the modulus is prime.- Parameters:
a
- The base.n
- The exponent.- Returns:
an mod m
.
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