Created
May 4, 2016 22:55
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/// <summary> | |
/// Fast exponential approximation. | |
/// </summary> | |
/// <remarks> | |
/// Based on "A Fast, Compact Approximation of the Exponential Function" by Nicol N.Schraudolph (1999) | |
/// <code>e^x ~ a*x + b | |
/// a = 2 ^ (mantissa bits) / ln(2) ~ 12102203 | |
/// b = (exponent bias) * 2^(mantissa bits) ~ 1065353216</code> | |
/// </remarks> | |
/// <param name="x">A number specifying a power.</param> | |
/// <returns>The number e raised to the power x.</returns> | |
public static float FastExp(float x) | |
{ | |
var temp = (int)(12102203 * x + 1065353216); | |
return BitConverter.ToSingle(BitConverter.GetBytes(temp), 0); | |
} |
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