Tag: Python

Genetic Algorithms, News, Pyevolve, Time Waste

Travelling Salesman on Sony PSP using Stackless Python + Pyevolve

This is my first PoC of the Travelling Salesman Problem on PSP, since I’ve installed the Pyevolve on the Sony PSP,  I can optimize any problem while using the graphical interface of PSP (in that problem I’m using the 2D functions to plot the cities and the path) to show results in real-time. Here is the video, the quality is very low, I’ve used my cellphone 🙂

Here is the source code I’ve used, the Pyevolve version of this example is the development version r166, which in the future will be the 0.6 final release (I’m working on many new features yet, so it will take time to release), however, this PoC should work on 0.5 release too:

import psp2d, pspos

WHITE_COLOR = psp2d.Color(255,255,255)
CLEAR_COLOR = psp2d.Color(0,0,0,255)
RED_COLOR   = psp2d.Color(255, 0, 0)

cm     = []
coords = []
CITIES = 20

pspos.setclocks(333,166)
psp_scr  = psp2d.Screen()
psp_font = psp2d.Font('font.png')
psp_scr.clear(CLEAR_COLOR)
psp_font.drawText(psp_scr, 0, 5, "Loading Pyevolve modules...")
psp_scr.swap()

from pyevolve import G1DList
from pyevolve import GSimpleGA
from pyevolve import GAllele
from pyevolve import Mutators
from pyevolve import Crossovers
from pyevolve import Consts

from random import shuffle as rand_shuffle, randint as rand_randint
from math import sqrt

def cartesian_matrix(coords):
   """ A distance matrix """
   matrix={}
   for i,(x1,y1) in enumerate(coords):
      for j,(x2,y2) in enumerate(coords):
         dx, dy = x1-x2, y1-y2
         dist=sqrt(dx*dx + dy*dy)
         matrix[i,j] = dist
   return matrix

def tour_length(matrix, tour):
   """ Returns the total length of the tour """
   total = 0
   for i in range(CITIES):
      j      = (i+1)%CITIES
      total += matrix[tour[i], tour[j]]
   return total

def write_tour_to_img(coords, tour):
   """ The function to plot the graph """
   psp_scr.clear(CLEAR_COLOR)
   for i in range(CITIES):
      j      = (i+1)%CITIES
      city_i = tour[i]
      city_j = tour[j]
      x1, y1 = coords[city_i]
      x2, y2 = coords[city_j]
      psp_scr.drawLine(int(x1), int(y1), int(x2), int(y2), WHITE_COLOR)
      psp_font.drawText(psp_scr, int(x1)+7, int(y1)-5, str(i))
      psp_scr.fillRect(int(x1), int(y1), 6, 6, RED_COLOR)

   psp_scr.swap()

def G1DListTSPInitializator(genome, **args):
   """ The initializator for the TSP """
   lst = [i for i in xrange(genome.getListSize())]
   rand_shuffle(lst)
   genome.genomeList = lst

def evolve_callback(ga_engine):
   """ Callback called every generation by Pyevolve """
   write_tour_to_img(coords, ga_engine.bestIndividual())
   return False

def main_run():
   global cm, coords

   width, height = psp_scr.size
   coords = [(rand_randint(0, width),rand_randint(0, height))
                 for i in xrange(CITIES)]
   cm     = cartesian_matrix(coords)

   setOfAlleles = GAllele.GAlleles(homogeneous=True)
   range_allele = GAllele.GAlleleRange(0, len(coords)-1)
   setOfAlleles.add(range_allele)

   genome = G1DList.G1DList(len(coords))
   genome.setParams(allele=setOfAlleles)

   genome.evaluator.set(lambda chromosome: tour_length(cm, chromosome))
   genome.mutator.set(Mutators.G1DListMutatorSwap)
   genome.crossover.set(Crossovers.G1DListCrossoverOX)
   genome.initializator.set(G1DListTSPInitializator)

   ga = GSimpleGA.GSimpleGA(genome)
   ga.setMinimax(Consts.minimaxType["minimize"])
   ga.setGenerations(300)
   ga.setPopulationSize(200)
   ga.setCrossoverRate(1.0)
   ga.setMutationRate(0.1)
   ga.stepCallback.set(evolve_callback)

   ga.evolve()

if __name__ == "__main__":
   main_run()
by Christian S. Perone
Genetic Algorithms, Pyevolve, Python

Rosenbrock’s banana function and friends

This post is a report of an optimization test suite applied to Pyevolve GA Core.

I’m writing a paper about Pyevolve and I’ve done some tests on the GA quality of Pyevolve with must common optimization test functions: Schaffer, Rastringin, Sphere, Ackley and the absolute GA-hard Rosenbrock. Follows in the end of the post, the results of the trials, I’ve exported the latex formulae as images.

The only function that the GA had some trouble (it failed to find the global minima in 3 of 10 trials, the “fail” term means that it had not found an optimal solution for 5.000 generations) was the Rosenbrock’s function with 20 variables, also known as Rosenbrock’s banana function due the dinstinctive shape of the contour lines, here is the 3D plot with 2 variables.

As Wikipedia says,

This function is often used to test performance of optimization algorithms. The global minimum is inside a long, narrow, parabolic shaped flat valley. To find the valley is trivial, however to converge to the global minimum is difficult.

However, this behavior was not unexpected, since we can note the same on the research of [1], [2], [3] and [4], among other many papers.

I think this trial results brings more reliability to the framework, when the Pyevolve paper was published, I’ll post it here.

[1] Seredynski, Franciszek, et. al. (2003). “Function Optimization with Coevolutionary Algorithms”, in International Intelligent Information Processing and Web Mining Conference.

[2] Hiroyasu, Tomoyuki, et. al. (1999). “Distributed Genetic Algorithms with Randomized Migration Rate”, IEEE Proceedings of Systems, Man and Cybernetics Conference SMC’99, Vol. 1, pp. 689-694.

[3] Bouvry, Pascal, et. al. (1997). “Distributed evolutionary optimization in Manifold: the Rosenbrock’s function case study”, Duke University.

[4] Panait, Liviu (2002). “A comparison of two competitive fitness functions”, in GECCO 2002: Proceedings of the Genetic and Evolutionary Computation Conference.

by Christian S. Perone
Genetic Algorithms, Pyevolve, Python

Pyevolve on Sony PSP ! (genetic algorithms on PSP)

Sony PSP can be more interesting than funny sometimes. Few people know about the potential of the PSP port of Stackless Python 2.5.2. This great port of python was done by Carlos E. and you can find more information about the progress of the port on his blog.

Well, I’ve tested the Pyevolve GA framework on the Stackless Python for PSP and for my surprise, it worked without changing one single line of code on the framework due the fact of Pyevolve has been written in pure Python (except the platform specific issue like the Interactive Mode, but this issue is automaticly disabled on unsupported platforms).

So now, we have Genetic Algorithms on PSP.

Follow some screenshots (click to enlarge):

psp2psp1

The GA running on the PSP screenshot is the minimization of the Sphere function.

Here is the steps to install Pyevolve on PSP:

PSP Stackless Python Installation

1) First, create a directory called “python” on your PSP under the “/PSP/GAME” and the directory structure “/python/site-packages/” on the root of your memory stick (this last directory will be used to put Pyevolve later).
2) Copy the EBOOT.PBP and the python.zip files to this created directory;

Pyevolve Installation

3) Download the Pyevolve source and copy the directory called “pyevolve” to the created directory “/python/site-packages/”, the final directory structure will be: “/python/site-packages/pyevolve”

Ready ! Now you can import Pyevolve modules inside scripts on your PSP, of course you can’t use the graphical plotting tool or some DB Adapters of Pyevolve, but the GA Core it’s working very well.

Here is some basic usage of PSP Stackless Python port. I’ve used the psp2d module to show the information on screen. When I got more time, I’ll port the visualization of the TSP problem to use the psp2d, it will be nice to see Traveling Salesperson Problem running with real-time visualization on PSP =)

Related Links

Google Code Project of PSP Stackless Python

by Christian S. Perone
Genetic Algorithms, Pyevolve, Python

Pyevolve: the effect of Linear Scaling

There’s an interesting graph in Pyevolve which is a heat-like graph of the population raw and fitness scores. In this graph you can note the effect of Linear Scaling over the scores, the raw scores graph is in left and the fitness scaled scores is in the right, this plot uses the Gaussian interpolation method.

linear

This graph feature is very interesting to study the effects of selections and scaling schemes and even to see the propagation of best individuals on the population while evolving, I think this graph should be more explored.

by Christian S. Perone
News, Python, Time Waste

Python: 3D real-time debugging and function call structure

Here is two videos of a small script (python and xmlrpc calls to ubigraph visualization server) created to show a 3D graph of  the function call structure of a python application, the first shows only the structure created while running the application and the next video shows a debugging-like tool, it changes the node color to red when the function is called, and the labels shows: function name, python file name and the line on the python file where the code is.

Update (26/02): download here the script source-code.

To use the script, start the Ubigraph visualization server and add the profile module to your python application, it will looks like this:

import prof3d

def run_main():
   # your code

if __name__ == "__main__":
   prof3d.profile_me()
   run_main()

by Christian S. Perone
Pyevolve, Python

Pyevolve profiling dot graph

I’ve created a profiling dot graph of the pyevolve_example15_rosenbrock.py with the Gprof2Dot, this Pyevolve example is the minimization of the Rosenbrock function with 20 variables.

stat

I’ve created that graph to show the call structure of Pyevolve, as you can see, the accumulation in FunctionSlot applyFunctions method is the effect of the use of FunctionSlot use in many operations like scaling,  selection, evaluation, crossover and mutation.

by Christian S. Perone
Python

Python: acessing near real-time MODIS images and fire data from NASA’s Aqua and Terra satellites

From Modis Rapid Response System site:

The MODIS Rapid Response System was developed to provide daily satellite images of the Earth’s landmasses in near real time. True-color, photo-like imagery and false-color imagery are available within a few hours of being collected, making the system a valuable resource (…).
The Moderate Resolution Imaging Spectroradiometer (MODIS) flies onboard NASA’s Aqua and Terra satellites as part of the NASA-centered international Earth Observing System. Both satellites orbit the Earth from pole to pole, seeing most of the globe every day. Onboard Terra, MODIS sees the Earth during the morning, while Aqua MODIS orbits the Earth in the afternoon.

One thing that a few people know is that everyone can have access to a near real-time moderate resolution images from two NASA satellites (Aqua and Terra) which orbits the earth from pole to pole every day and captures images and data like thermal anomalies from the most part of the globe.

In this post, I’ll show how to get and plot those imagery and data to a map using Python and Matplotlib + Basemap toolkit.

The Aqua and Terra orbits

The "Terra" orbit

(more…)

by Christian S. Perone
Genetic Algorithms, Pyevolve, Python

Pyevolve: work on the distributed Genetic Algorithm support

I’m currently working on the distributed GA support for the Pyevolve framework, the approach I’m using to network communication (individuals migration) is the hightweigh and unreliable UDP protocol, due it’s performance (for lan/wan) and broadcasting compatibility.

The distributed GA will have options to create the logical migration topology for the connected nodes (islands of evolution), migration schemes, migration rates and other parameters.

by Christian S. Perone

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