Upwind face variable for Karim Khayrat

gistfile1.txt

{
 "metadata": {
  "name": "upwind"
 },
 "nbformat": 3,
 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "from fipy.variables.cellToFaceVariable import _CellToFaceVariable\n",
      "from fipy.tools import numerix\n",
      "\n",
      "class UpwindFaceVariable(_CellToFaceVariable):\n",
      "    def __init__(self, var, velocity):\n",
      "        self.velocity = velocity\n",
      "        super(UpwindFaceVariable, self).__init__(var)\n",
      "        \n",
      "    def _calcValue_(self, alpha, id1, id2):\n",
      "        cell1 = numerix.take(self.var, id1, axis=-1)\n",
      "        cell2 = numerix.take(self.var, id2, axis=-1)\n",
      "        normals = self.mesh.faceNormals\n",
      "        flow = numerix.sum(normals * self.velocity)\n",
      "        return numerix.where(flow > 0, cell1, cell2)\n",
      "        "
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 13
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import fipy as fp\n",
      "\n",
      "m = fp.Grid1D(nx=4)\n",
      "v = fp.CellVariable(mesh=m, value=(0, 1, 2, 3))\n",
      "velocity = fp.FaceVariable(mesh=m, rank=1, value=2 - m.faceCenters)\n",
      "up = UpwindFaceVariable(v, velocity)\n",
      "print v\n",
      "print velocity\n",
      "print up"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "[0 1 2 3]\n",
        "[[ 2.  1.  0. -1. -2.]]\n",
        "[0 0 2 3 3]\n"
       ]
      }
     ],
     "prompt_number": 29
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import fipy as fp\n",
      "\n",
      "m = fp.Grid2D(nx=2, ny=2)\n",
      "v = fp.CellVariable(mesh=m, value=(0, 1, 2, 3))\n",
      "X, Y = m.faceCenters\n",
      "velocity = fp.FaceVariable(mesh=m, rank=1)\n",
      "velocity[0] = Y - 1\n",
      "velocity[1] = 1 - X\n",
      "up = UpwindFaceVariable(v, velocity)\n",
      "print v\n",
      "print velocity\n",
      "print up"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "[0 1 2 3]\n",
        "[[-1.  -1.   0.   0.   1.   1.  -0.5 -0.5 -0.5  0.5  0.5  0.5]\n",
        " [ 0.5 -0.5  0.5 -0.5  0.5 -0.5  1.   0.  -1.   1.   0.  -1. ]]\n",
        "[0 1 0 3 2 3 0 1 1 2 2 3]\n"
       ]
      }
     ],
     "prompt_number": 30
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [],
     "language": "python",
     "metadata": {},
     "outputs": []
    }
   ],
   "metadata": {}
  }
 ]
}