/// <summary>
/// Samples a function equidistant within the provided interval.
/// </summary>
/// <param name="function">The real-domain function to sample.</param>
/// <param name="intervalBegin">The real domain interval begin where to start sampling.</param>
/// <param name="intervalEnd">The real domain interval end where to stop sampling.</param>
/// <param name="sampleCount">The number of samples to generate.</param>
/// <param name="samplePoints">The real domain points where the samples are taken at.</param>
/// <typeparam name="T">The value type of the function to sample.</typeparam>
/// <returns>The generated sample vector.</returns>
/// <exception cref="ArgumentNullException" />
/// <exception cref="ArgumentOutOfRangeException" />
public static T[] EquidistantInterval <T>(Func <double, T> function, double intervalBegin, double intervalEnd, int sampleCount,
out double[] samplePoints)
{
function.ShouldNotBeNull("function");
sampleCount.ShouldBePositiveOrZero("sampleCount");
if (sampleCount == 0)
{
samplePoints = new double[0];
return(new T[0]);
}
if (sampleCount == 1)
{
samplePoints = new double[] { (intervalBegin + intervalEnd) / 2.0 };
return(new T[] { function(samplePoints[0]) });
}
var step = (intervalEnd - intervalBegin) / (sampleCount - 1);
samplePoints = PLinqTool.Generate(sampleCount, i => intervalBegin + i * step).ToArray();
samplePoints[samplePoints.Length - 1] = intervalEnd;
var result =
samplePoints
.AsParallel()
.AsOrdered()
.Select(x => function(x))
.ToArray();
result[result.Length - 1] = function(intervalEnd);
return(result);
}
/// <summary>
/// Samples a function equidistant starting from the provided location with a fixed step length.
/// </summary>
/// <param name="function">The real-domain function to sample.</param>
/// <param name="start">The real domain location offset where to start sampling.</param>
/// <param name="step">The real domain step length between the equidistant samples.</param>
/// <param name="sampleCount">The number of samples to generate.</param>
/// <param name="samplePoints">The real domain points where the samples are taken at.</param>
/// <typeparam name="T">The value type of the function to sample.</typeparam>
/// <returns>The generated sample vector.</returns>
/// <exception cref="ArgumentNullException" />
/// <exception cref="ArgumentOutOfRangeException"/>
public static T[] EquidistantStartingAt <T>(Func <double, T> function, double start, double step, int sampleCount,
out double[] samplePoints)
{
function.ShouldNotBeNull("function");
sampleCount.ShouldBePositiveOrZero("sampleCount");
samplePoints = PLinqTool.Generate(start, step, sampleCount, x => x).ToArray();
return
(samplePoints
.AsParallel()
.AsOrdered()
.Select(x => function(x))
.ToArray());
}
/// <summary>
/// Samples a periodic function equidistant within one period, but omits the last sample such that the sequence
/// can be concatenated together.
/// </summary>
/// <param name="function">The real-domain function to sample.</param>
/// <param name="periodLength">The real domain full period length.</param>
/// <param name="periodOffset">The real domain offset where to start the sampling period.</param>
/// <param name="sampleCount">The number of samples to generate.</param>
/// <param name="samplePoints">The real domain points where the samples are taken at.</param>
/// <typeparam name="T">The value type of the function to sample.</typeparam>
/// <returns>The generated sample vector.</returns>
/// <exception cref="ArgumentNullException" />
/// <exception cref="ArgumentOutOfRangeException"/>
public static T[] EquidistantPeriodic <T>(Func <double, T> function, double periodLength, double periodOffset, int sampleCount,
out double[] samplePoints)
{
function.ShouldNotBeNull("function");
sampleCount.ShouldBePositive("sampleCount");
var step = periodLength / sampleCount;
samplePoints = PLinqTool.Generate(sampleCount, i => periodOffset + i * step).ToArray();
return
(samplePoints
.AsParallel()
.AsOrdered()
.Select(x => function(x))
.ToArray());
}
