108 lines
3.1 KiB
C#
108 lines
3.1 KiB
C#
using System;
|
|
using System.Collections.Generic;
|
|
|
|
namespace ResistorMesh {
|
|
class Node {
|
|
public Node(double v, int fixed_) {
|
|
V = v;
|
|
Fixed = fixed_;
|
|
}
|
|
|
|
public double V { get; set; }
|
|
public int Fixed { get; set; }
|
|
}
|
|
|
|
class Program {
|
|
static void SetBoundary(List<List<Node>> m) {
|
|
m[1][1].V = 1.0;
|
|
m[1][1].Fixed = 1;
|
|
|
|
m[6][7].V = -1.0;
|
|
m[6][7].Fixed = -1;
|
|
}
|
|
|
|
static double CalcuateDifference(List<List<Node>> m, List<List<Node>> d, int w, int h) {
|
|
double total = 0.0;
|
|
for (int i = 0; i < h; i++) {
|
|
for (int j = 0; j < w; j++) {
|
|
double v = 0.0;
|
|
int n = 0;
|
|
if (i > 0) {
|
|
v += m[i - 1][j].V;
|
|
n++;
|
|
}
|
|
if (j > 0) {
|
|
v += m[i][j - 1].V;
|
|
n++;
|
|
}
|
|
if (i + 1 < h) {
|
|
v += m[i + 1][j].V;
|
|
n++;
|
|
}
|
|
if (j + 1 < w) {
|
|
v += m[i][j + 1].V;
|
|
n++;
|
|
}
|
|
v = m[i][j].V - v / n;
|
|
d[i][j].V = v;
|
|
if (m[i][j].Fixed == 0) {
|
|
total += v * v;
|
|
}
|
|
}
|
|
}
|
|
return total;
|
|
}
|
|
|
|
static double Iter(List<List<Node>> m, int w, int h) {
|
|
List<List<Node>> d = new List<List<Node>>(h);
|
|
for (int i = 0; i < h; i++) {
|
|
List<Node> t = new List<Node>(w);
|
|
for (int j = 0; j < w; j++) {
|
|
t.Add(new Node(0.0, 0));
|
|
}
|
|
d.Add(t);
|
|
}
|
|
|
|
double[] curr = new double[3];
|
|
double diff = 1e10;
|
|
|
|
while (diff > 1e-24) {
|
|
SetBoundary(m);
|
|
diff = CalcuateDifference(m, d, w, h);
|
|
for (int i = 0; i < h; i++) {
|
|
for (int j = 0; j < w; j++) {
|
|
m[i][j].V -= d[i][j].V;
|
|
}
|
|
}
|
|
}
|
|
|
|
for (int i = 0; i < h; i++) {
|
|
for (int j = 0; j < w; j++) {
|
|
int k = 0;
|
|
if (i != 0) k++;
|
|
if (j != 0) k++;
|
|
if (i < h - 1) k++;
|
|
if (j < w - 1) k++;
|
|
curr[m[i][j].Fixed + 1] += d[i][j].V * k;
|
|
}
|
|
}
|
|
|
|
return (curr[2] - curr[0]) / 2.0;
|
|
}
|
|
|
|
const int S = 10;
|
|
static void Main(string[] args) {
|
|
List<List<Node>> mesh = new List<List<Node>>(S);
|
|
for (int i = 0; i < S; i++) {
|
|
List<Node> t = new List<Node>(S);
|
|
for (int j = 0; j < S; j++) {
|
|
t.Add(new Node(0.0, 0));
|
|
}
|
|
mesh.Add(t);
|
|
}
|
|
|
|
double r = 2.0 / Iter(mesh, S, S);
|
|
Console.WriteLine("R = {0:F15}", r);
|
|
}
|
|
}
|
|
}
|