symlognorm_vmin.ipynb

{
 "metadata": {
  "name": "",
  "signature": "sha256:d2c53345c12b26146e69f399ffbd1c6eadec273bb56825c0838fe563abeffd8f"
 },
 "nbformat": 3,
 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import sys, numpy, matplotlib\n",
      "print('Python', sys.version)\n",
      "print('numpy', numpy.__version__)\n",
      "print('matplotlib', matplotlib.__version__)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Python 3.4.1 (default, May 19 2014, 17:23:49) \n",
        "[GCC 4.9.0 20140507 (prerelease)]\n",
        "numpy 1.8.1\n",
        "matplotlib 1.3.1\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "from numpy import array\n",
      "from matplotlib.colors import SymLogNorm"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 2
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "data = array([-1, -0.2, 0, 0.01, 0.2, 4])"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 3
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "norm1 = SymLogNorm(0.1, vmin=-1, vmax=40)\n",
      "norm2 = SymLogNorm(0.1, vmax=40)\n",
      "\n",
      "print(norm1(data))\n",
      "print(norm2(data))"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "[-inf -inf  nan  inf  inf  inf]\n",
        "[ 0.          0.14046408  0.33902607  0.35283281  0.53758806  0.79904133]\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stderr",
       "text": [
        "/usr/lib/python3.4/site-packages/matplotlib/colors.py:1077: RuntimeWarning: divide by zero encountered in true_divide\n",
        "  resdat /= (self._upper - self._lower)\n",
        "/usr/lib/python3.4/site-packages/matplotlib/colors.py:1077: RuntimeWarning: invalid value encountered in true_divide\n",
        "  resdat /= (self._upper - self._lower)\n"
       ]
      }
     ],
     "prompt_number": 4
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "print(norm1.vmin, norm1.vmax, norm1._lower, norm1._upper)\n",
      "print(norm2.vmin, norm2.vmax, norm2._lower, norm2._upper)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "-1 40 0 0\n",
        "-1.0 40 -0.388456179986 0.757344125398\n"
       ]
      }
     ],
     "prompt_number": 5
    }
   ],
   "metadata": {}
  }
 ]
}