X-Git-Url: http://git.treefish.org/~alex/phys/latlib.git/blobdiff_plain/2dbd0cb896ebdc75901cbed1b15df238670a0f6d..385a5a6cbcab9001633efd700b2ffdeaf1aaaf6d:/neigh.cpp?ds=sidebyside

diff --git a/neigh.cpp b/neigh.cpp
new file mode 100644
index 0000000..a25d1e7
--- /dev/null
+++ b/neigh.cpp
@@ -0,0 +1,28 @@
+#include "neigh.h"
+
+neigh::neigh(const int& dimension, const int& length)
+{
+  nfield = new int[ipow(dimension,length)*2*dimension];
+
+  for (int ipos = 0; ipos < ipow(length,dimension); ipos++)
+    {
+      for (int idir = 0; idir < 2*dimension; idir++)
+	{
+	  if ( idir < dimension ) //pos direction
+	    {
+	      if ( ( ipos/ipow(length,idir%dimension) ) % length == length-1 )
+		nfield[ipos*2*dimension + idir] = ipos - ipow(length,idir%dimension)*(length-1);
+	      else
+		nfield[ipos*2*dimension + idir] = ipos + ipow(length,idir%dimension);
+	    }
+	  else //negative dir
+	    {
+	      if ( ( ipos/ipow(length,idir%dimension) ) % length == 0 )
+		nfield[ipos*2*dimension + idir] = ipos + ipow(length,idir%dimension)*(length-1);
+	      else
+		nfield[ipos*2*dimension + idir] = ipos - ipow(length,idir%dimension);
+	    }
+	  
+	}
+    }
+}