1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
|
/*
* rechteck.cpp
*
* (c) 2021 Prof Dr Andreas Müller, OST Ostschweizer Fachhochschule
*/
#include <cmath>
#include <cstdlib>
#include <cstdio>
#include <complex>
#include <iostream>
double ast = 1;
std::complex<double> integrand(double k, const std::complex<double>& z) {
std::complex<double> s = z * z;
std::complex<double> eins(1);
std::complex<double> result = eins / sqrt((eins - s) * (eins - k * k * s));
return ast * ((result.imag() < 0) ? -result : result);
}
std::complex<double> segment(double k, const std::complex<double>& z1,
const std::complex<double>& z2, int n = 100) {
std::complex<double> dz = z2 - z1;
std::complex<double> summe(0);
double h = 1. / n;
summe = integrand(k, z1);
summe += integrand(k, z2);
for (int i = 1; i < n; i++) {
double t = i * h;
std::complex<double> z = (1 - t) * z1 + t * z2;
summe += 2. * integrand(k, z);
}
return dz * h * summe / 2.;
}
int main(int argc, char *argv[]) {
double k = 0.5;
double y = -0.0001;
double xstep = -0.1;
ast = 1;
std::complex<double> z(0, y);
std::complex<double> w = segment(k, std::complex<double>(0), z);
std::cout << z << std::endl;
int counter = 100;
while (counter-- > 0) {
std::complex<double> znext = z + std::complex<double>(xstep);
std::complex<double> incr = segment(k, z, znext);
w += incr;
std::cout << znext << " -> " << w << ", ";
std::cout << integrand(k, znext) << std::endl;
z = znext;
}
return EXIT_SUCCESS;
}
|
