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public Multiply ( BigInteger b ) : |
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| b | BigInteger | |
| return | ||
/**
* Computes the norm of an element <code>λ</code> of
* <code><b>R</b>[τ]</code>, where <code>λ = u + vτ</code>
* and <code>u</code> and <code>u</code> are real numbers (elements of
* <code><b>R</b></code>).
* @param mu The parameter <code>μ</code> of the elliptic curve.
* @param u The real part of the element <code>λ</code> of
* <code><b>R</b>[τ]</code>.
* @param v The <code>τ</code>-adic part of the element
* <code>λ</code> of <code><b>R</b>[τ]</code>.
* @return The norm of <code>λ</code>.
*/
public static SimpleBigDecimal Norm(sbyte mu, SimpleBigDecimal u, SimpleBigDecimal v)
{
SimpleBigDecimal norm;
// s1 = u^2
SimpleBigDecimal s1 = u.Multiply(u);
// s2 = u * v
SimpleBigDecimal s2 = u.Multiply(v);
// s3 = 2 * v^2
SimpleBigDecimal s3 = v.Multiply(v).ShiftLeft(1);
if (mu == 1)
{
norm = s1.Add(s2).Add(s3);
}
else if (mu == -1)
{
norm = s1.Subtract(s2).Add(s3);
}
else
{
throw new ArgumentException("mu must be 1 or -1");
}
return(norm);
}
/**
* Computes the norm of an element <code>λ</code> of
* <code><b>R</b>[τ]</code>, where <code>λ = u + vτ</code>
* and <code>u</code> and <code>u</code> are real numbers (elements of
* <code><b>R</b></code>).
* @param mu The parameter <code>μ</code> of the elliptic curve.
* @param u The real part of the element <code>λ</code> of
* <code><b>R</b>[τ]</code>.
* @param v The <code>τ</code>-adic part of the element
* <code>λ</code> of <code><b>R</b>[τ]</code>.
* @return The norm of <code>λ</code>.
*/
public static SimpleBigDecimal Norm(sbyte mu, SimpleBigDecimal u, SimpleBigDecimal v)
{
SimpleBigDecimal norm;
// s1 = u^2
SimpleBigDecimal s1 = u.Multiply(u);
// s2 = u * v
SimpleBigDecimal s2 = u.Multiply(v);
// s3 = 2 * v^2
SimpleBigDecimal s3 = v.Multiply(v).ShiftLeft(1);
if(mu == 1)
{
norm = s1.Add(s2).Add(s3);
}
else if(mu == -1)
{
norm = s1.Subtract(s2).Add(s3);
}
else
{
throw new ArgumentException("mu must be 1 or -1");
}
return norm;
}
