{ "metadata": { "name": "basic" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "code", "collapsed": false, "input": [ "from start import *" ], "language": "python", "metadata": {}, "outputs": [], "prompt_number": 1 }, { "cell_type": "markdown", "metadata": {}, "source": [ "Reshaping" ] }, { "cell_type": "code", "collapsed": false, "input": [ "a = np.arange(12)\n", "a" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "pyout", "prompt_number": 4, "text": [ "array([ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11])" ] } ], "prompt_number": 4 }, { "cell_type": "code", "collapsed": false, "input": [ "a.shape" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "pyout", "prompt_number": 5, "text": [ "(12,)" ] } ], "prompt_number": 5 }, { "cell_type": "code", "collapsed": false, "input": [ "print np.reshape(a, (2,6) )" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "[[ 0 1 2 3 4 5]\n", " [ 6 7 8 9 10 11]]\n" ] } ], "prompt_number": 6 }, { "cell_type": "code", "collapsed": false, "input": [ "# unknown dimension\n", "a.shape = ( -1, 2)\n", "print a" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "[[ 0 1]\n", " [ 2 3]\n", " [ 4 5]\n", " [ 6 7]\n", " [ 8 9]\n", " [10 11]]\n" ] } ], "prompt_number": 7 }, { "cell_type": "code", "collapsed": false, "input": [ "# flatten\n", "for i in a.flat: # iterator\n", " print i " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "0\n", "1\n", "2\n", "3\n", "4\n", "5\n", "6\n", "7\n", "8\n", "9\n", "10\n", "11\n" ] } ], "prompt_number": 8 }, { "cell_type": "code", "collapsed": false, "input": [ "np.ravel(a)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "pyout", "prompt_number": 9, "text": [ "array([ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11])" ] } ], "prompt_number": 9 }, { "cell_type": "code", "collapsed": false, "input": [ "a.T" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "pyout", "prompt_number": 10, "text": [ "array([[ 0, 2, 4, 6, 8, 10],\n", " [ 1, 3, 5, 7, 9, 11]])" ] } ], "prompt_number": 10 }, { "cell_type": "code", "collapsed": false, "input": [ "a = np.ravel(a)" ], "language": "python", "metadata": {}, "outputs": [], "prompt_number": 11 }, { "cell_type": "code", "collapsed": false, "input": [ "a" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "pyout", "prompt_number": 12, "text": [ "array([ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11])" ] } ], "prompt_number": 12 }, { "cell_type": "markdown", "metadata": {}, "source": [ "Checking dimensions:" ] }, { "cell_type": "code", "collapsed": false, "input": [ "a = np.atleast_2d(a)\n", "a" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "pyout", "prompt_number": 15, "text": [ "array([[ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]])" ] } ], "prompt_number": 15 }, { "cell_type": "code", "collapsed": false, "input": [ "a.shape" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "pyout", "prompt_number": 16, "text": [ "(1, 12)" ] } ], "prompt_number": 16 }, { "cell_type": "code", "collapsed": false, "input": [ "# reducing:\n", "a.shape = (2,1,6)\n", "a.shape" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "pyout", "prompt_number": 19, "text": [ "(2, 1, 6)" ] } ], "prompt_number": 19 }, { "cell_type": "code", "collapsed": false, "input": [ "b = np.squeeze(a)\n", "b.shape" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "pyout", "prompt_number": 20, "text": [ "(2, 6)" ] } ], "prompt_number": 20 }, { "cell_type": "code", "collapsed": false, "input": [ "# re-arranging:\n", "b\n", "print np.flipud(b)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "[[ 6 7 8 9 10 11]\n", " [ 0 1 2 3 4 5]]\n" ] } ], "prompt_number": 22 }, { "cell_type": "code", "collapsed": false, "input": [ "print np.fliplr(b)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "[[ 5 4 3 2 1 0]\n", " [11 10 9 8 7 6]]\n" ] } ], "prompt_number": 23 }, { "cell_type": "code", "collapsed": false, "input": [], "language": "python", "metadata": {}, "outputs": [] } ], "metadata": {} } ] }