Blockserver

gistfile1.txt

{
 "metadata": {
  "name": "Blockserver_example"
 },
 "nbformat": 3,
 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "code",
     "collapsed": false,
     "input": "import BlockServer\n%cd 'D:\\'",
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": "D:\\\n"
      }
     ],
     "prompt_number": 5
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": "L8_1 = r'LC81970242013202LGN00.vrt'\nL8_2 = r'LC81970242013346NSG00.vrt'",
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 6
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": "# define inputs and outputs\ninputs = {'scene1': L8_1,\n          'scene2': L8_2}\n\noutputs = {'ndvi_change': 'ndvi_diff.tif',\n           'albedo_change': 'albedo_diff.tif'}\n\n# options are GDAL driver options\nobj = BlockServer(inputs=inputs, outputs=outputs,\n                  options=[\"COMPRESS=PACKBITS\", \"TILED=YES\", \"BLOCKXSIZE=128\", \"BLOCKYSIZE=128\"])\n\n# iterate over the blocks\nfor num in obj.GetBlockIDs():\n    \n    # returns a dict with arrays of each input\n    blck = obj.GetBlock(num)    \n    \n    # do something with the data\n    sc1 = blck['scene1']\n    ndvi1 = (sc1[5,:,:] - sc1[4,:,:]) / (sc1[5,:,:] + sc1[4,:,:])\n    albe1 = np.average(sc1, axis=0)\n\n    sc2 = blck['scene2']\n    ndvi2 = (sc2[5,:,:] - sc2[4,:,:]) / (sc2[5,:,:] + sc2[4,:,:])\n    albe2 = np.average(sc2, axis=0)\n       \n    ndvi_diff = ndvi1 - ndvi2\n    albe_diff = albe1 - albe2\n    \n    # write the results, the dict must match the\n    # earlier 'outputs' dict\n    obj.WriteBlock(num, {'ndvi_change': ndvi_diff,\n                         'albedo_change': albe_diff})\n\nobj.Close()",
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stderr",
       "text": "-c:20: RuntimeWarning: divide by zero encountered in divide\n-c:24: RuntimeWarning: divide by zero encountered in divide\n"
      }
     ],
     "prompt_number": 7
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": "",
     "language": "python",
     "metadata": {},
     "outputs": []
    }
   ],
   "metadata": {}
  }
 ]
}