From: hackbard <hackbard>
Date: Sat, 10 May 2003 02:39:51 +0000 (+0000)
Subject: fixed boundary cond. bug
X-Git-Url: https://hackdaworld.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a3f5c519038ec2d2ffd126e0d76277b1fa92065a;p=physik%2Fising.git

fixed boundary cond. bug
---

diff --git a/ising.c b/ising.c
index e43b4be..4ff3ba8 100644
--- a/ising.c
+++ b/ising.c
@@ -12,19 +12,20 @@
 #include <string.h>
 #include <math.h>
 #include <time.h>
+
 #include "dfbapi.h"
 
 #define X 200
 #define Y 200
-#define MAX_T 100
+#define MAX_T 10
 
 int main(int argc, char **argv)
 {
  unsigned char *atom;
  char *arg_v[4];
- char m_text[30];
- char t_text[30];
- char b_text[30];
+ char m_text[64];
+ char t_text[64];
+ char b_text[64];
  int max_x,x_c,max_y,y_c;
  int i;
  int count_p;
@@ -57,21 +58,21 @@ int main(int argc, char **argv)
  
  for(T=1;T<MAX_T;T++)
  {
-  beta=20.0/T; /* k_B = 1 */
-  /* do 10 itterations, we will need more */
-  for(i=0;i<10;i++)
+  beta=5.0/T; /* k_B = 1 */
+  /* do 100 itterations, we will need more */
+  for(i=0;i<100;i++)
   {
 
+ M=0;
  for(x_c=0;x_c<max_x;x_c++)
  {
   for(y_c=0;y_c<max_y;y_c++)
   {
    count_p=0;
-   M=0;
-   if((*(atom+x_c+((2*y_c+1)%max_y)*max_x))&1) ++count_p;
-   if((*(atom+x_c+((2*y_c-1)%max_y)*max_x))&1) ++count_p;
-   if((*(atom+((2*x_c+1)%max_x)+y_c*max_x))&1) ++count_p;
-   if((*(atom+((2*x_c-1)%max_x)+y_c*max_x))&1) ++count_p;
+   if((*(atom+x_c+((y_c+max_y+1)%max_y)*max_x))&1) ++count_p;
+   if((*(atom+x_c+((y_c+max_y-1)%max_y)*max_x))&1) ++count_p;
+   if((*(atom+((max_x+x_c+1)%max_x)+y_c*max_x))&1) ++count_p;
+   if((*(atom+((max_x+x_c-1)%max_x)+y_c*max_x))&1) ++count_p;
    if(((*(atom+x_c+y_c*max_x))&1)==0) count_p=4-count_p;
    delta_e=(2*count_p-4)*S;
    if(delta_e<0) *(atom+x_c+y_c*max_x)=(*(atom+x_c+y_c*max_x)+1)&1;
@@ -80,14 +81,14 @@ int main(int argc, char **argv)
     if(1.0*rand()/RAND_MAX<exp(-1.0*delta_e*beta))
      *(atom+x_c+y_c*max_x)=(*(atom+x_c+y_c*max_x)+1)&1;
    }
-   if((*(atom+x_c+((2*y_c+1)%max_y)*max_x))&1) ++M;
+   if((*(atom+x_c+y_c*max_x))&1) ++M;
   }
  }
-  sprintf(t_text,"T = %d",T);
+  sprintf(t_text,"temp = %d",T);
   arg_v[1]=t_text;
-  sprintf(b_text,"b = %f",beta);
+  sprintf(b_text,"beta = %f",beta);
   arg_v[2]=b_text;
-  sprintf(m_text,"M = %f",1.0-2.0*M/(max_x*max_y));
+  sprintf(m_text,"magn = %f",1.0-2.0*M/(max_x*max_y));
   arg_v[3]=m_text;
   d2_lattice_draw(&d2_l,0,0,3,arg_v);
   }