add numerical recipes library

2025-09-12 18:55:25 +09:00
parent d4dff245bd
commit 2c75620ec9
1344 changed files with 63869 additions and 0 deletions
--- a/lib/nr/k_and_r/recipes/lop.c
+++ b/lib/nr/k_and_r/recipes/lop.c
@@ -0,0 +1,17 @@
+
+void lop(out,u,n)
+double **out,**u;
+int n;
+{
+	int i,j;
+	double h,h2i;
+
+	h=1.0/(n-1);
+	h2i=1.0/(h*h);
+	for (j=2;j<n;j++)
+		for (i=2;i<n;i++)
+			out[i][j]=h2i*(u[i+1][j]+u[i-1][j]+u[i][j+1]+u[i][j-1]-
+				4.0*u[i][j])+u[i][j]*u[i][j];
+	for (i=1;i<=n;i++)
+		out[i][1]=out[i][n]=out[1][i]=out[n][i]=0.0;
+}