XLPack API: C# example programs
How to call XLPack from C#
To call XLPack from C#, it is necessary to use DLL directly.
DLL interface program xlpack.cs is included in SDK, so that the calling program can easily call XLPack like built-in functions without considering the detail DLL interface by declaring “using static XLPack;”.
Two dimensional array is used for the coefficient matrix a. One dimensional array is used for the right hand matrix b.
C# example program (Example (1))
using System;
using System.IO;
using static XLPack;
public class Test
{
static void Test_dgesv()
{
const int n = 3;
double[,] a =
{{ 0.2, -0.32, -0.8 },
{ -0.11, 0.81, -0.92 },
{ -0.93, 0.37, -0.29 }};
double[] b = { -0.3727, 0.4319, -1.4247 };
int[] ipiv = new int[n];
int info;
dgesv(n, a, ipiv, b, out info);
Console.Write("x = {0} {1} {2}\n", b[0], b[1], b[2]);
Console.Write("info = {0}\n", info);
}
public static int Main(string[] args)
{
Test_dgesv();
return 0;
}
}Result
x = 0.86 0.64 0.51
info = 0
C# example program (Example (2))
In Example (2), the integral of f(x) is computed using qk15. qk15 requires the external function defining f(x). It can be coded in C# and qk15 will call it when necessary.
using System;
using System.IO;
using static XLPack;
public class Test
{
static double f_qk15(double x)
{
return 1/(1 + x*x);
}
static void Test_qk15()
{
double a, b, result, abserr;
a = 0; b = 4;
qk15(f_qk15, a, b, out result, out abserr);
Console.Write("result = {0}, abserr = {1}\n", result, abserr);
}
public static int Main(string[] args)
{
Test_qk15();
return 0;
}
}Result
result = 1.32581766136379, abserr = 0.00148272394121622
