jidt/demos/python/example6DynamicCallingMutua...

92 lines
4.3 KiB
Python
Executable File

##
## Java Information Dynamics Toolkit (JIDT)
## Copyright (C) 2012, Joseph T. Lizier
##
## This program is free software: you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation, either version 3 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program. If not, see <http://www.gnu.org/licenses/>.
##
# = Example 6 - Mutual information calculation with dynamic specification of calculator =
# This example shows how to write Python code to take advantage of the
# common interfaces defined for various information-theoretic calculators.
# Here, we use the common form of the infodynamics.measures.continuous.MutualInfoCalculatorMultiVariate
# interface (which is never named here) to write common code into which we can plug
# one of three concrete implementations (kernel estimator, Kraskov estimator or
# linear-Gaussian estimator) by dynamically supplying the class name of
# the concrete implementation.
from jpype import *
import random
import string
import numpy
import readFloatsFile
# Change location of jar to match yours:
jarLocation = "../../infodynamics.jar"
# Start the JVM (add the "-Xmx" option with say 1024M if you get crashes due to not enough memory space)
startJVM(getDefaultJVMPath(), "-ea", "-Djava.class.path=" + jarLocation)
#---------------------
# 1. Properties for the calculation (these are dynamically changeable):
# The name of the data file (relative to this directory)
datafile = '../data/4ColsPairedNoisyDependence-1.txt'
# List of column numbers for variables 1 and 2:
# (you can select any columns you wish to be contained in each variable)
variable1Columns = [0,1] # array indices start from 0 in python
variable2Columns = [2,3]
# The name of the concrete implementation of the interface
# infodynamics.measures.continuous.MutualInfoCalculatorMultiVariate
# which we wish to use for the calculation.
# Note that one could use any of the following calculators (try them all!):
# implementingClass = "infodynamics.measures.continuous.kraskov.MutualInfoCalculatorMultiVariateKraskov1" # MI([0,1], [2,3]) = 0.35507
# implementingClass = "infodynamics.measures.continuous.kernel.MutualInfoCalculatorMultiVariateKernel"
# implementingClass = "infodynamics.measures.continuous.gaussian.MutualInfoCalculatorMultiVariateGaussian"
implementingClass = "infodynamics.measures.continuous.kraskov.MutualInfoCalculatorMultiVariateKraskov1"
#---------------------
# 2. Load in the data
data = readFloatsFile.readFloatsFile(datafile)
# As numpy array:
A = numpy.array(data)
# Pull out the columns from the data set which correspond to each of variable 1 and 2:
variable1 = A[:,variable1Columns]
variable2 = A[:,variable2Columns]
#--------------------
# 3. Dynamically instantiate an object of the given class:
# (in fact, all java object creation in python is dynamic - it has to be,
# since the languages are interpreted. This makes our life slightly easier at this
# point than it is in demos/java/lateBindingDemo where we have to handle this manually)
indexOfLastDot = string.rfind(implementingClass, ".")
implementingPackage = implementingClass[:indexOfLastDot]
implementingBaseName = implementingClass[indexOfLastDot+1:]
miCalcClass = eval('JPackage(\'%s\').%s' % (implementingPackage, implementingBaseName))
miCalc = miCalcClass()
#--------------------
# 4. Start using the MI calculator, paying attention to only
# call common methods defined in the interface type
# infodynamics.measures.continuous.MutualInfoCalculatorMultiVariate
# not methods only defined in a given implementation class.
# a. Initialise the calculator to use the required number of
# dimensions for each variable:
miCalc.initialise(len(variable1Columns), len(variable2Columns))
# b. Supply the observations to compute the PDFs from:
miCalc.setObservations(variable1, variable2)
# c. Make the MI calculation:
miValue = miCalc.computeAverageLocalOfObservations()
print("MI calculator %s computed the joint MI as %.5f\n" % (implementingClass, miValue))