Hex, Bugs and More Physics | Emre S. Tasci

Mathematica Code for Andrew Moore – Information Gain Example This is what I’ve written implementing the two libraries. It calculates the information gain for Andrew Moore’s example in his Information Gain example (which can be accessed from his resourceful website on datamining: http://www.autonlab.org/tutorials/)

You will be needing the two libraries and you can download them from the related entries for Matrix and DataMining procedures.

Mathematica Library for DataMining
Functions Library Intended To Be Used In DataMining Procedures
11/2007
Emre S. Tasci
S&C / MSE / 3mE / TUDelftFunctions List (EF: Required External Functions)

• Int DMBooleEST[statement_]
  Converts True/False => 1/0
  EF – NONE
• Bool DMBooleEST[statement_]
  Converts 1/0 => True/False
  EF – NONE
• Int DMCondEntropyEST[MatrixIN_,var2_,var1_, posVal1_, posVal2_,probVar1_]
  Calculates the Conditional Entropy H(var2|var1)
  EF – MSelectEST, DMProbeEST, DMEntropyEST
• Int DMEntropyEST[problist_]
  Calculates the entropy given the probability list “problist”
  EF – NONE
• Matrix DMGenMatrixEST[dim_,file_]
  Generates a Matrix of [dim,dim] dimension and writes this matrix to the “file” file. Returns the matrix generated.
  EF – DMBooleEST, DMUnitizeEST
• List DMInfGainEST[MatrixIN_,varno_]
  Calculates the Information Gain related to the “varno” variable wrt to the remaining variables.
  EF -Â MDiffElementEST , MSwapEST, DMCondEntropyEST, DMEntropyEST, DMProbeEST
• Vector DMProbeEST[MatrixIN_,varno_,varlist_]
  Calculates the probabilities of the variables’ possible outcomes.
  EF – NONE;

Important!!! ————————————

Assumed form of the MatrixIN: ;



(i.e., values for the same variable are stored in ROWS, NOTÂ in COLUMNS!)

Mathematica Library for additional Matrix Functions

Functions Library Intended To Be Used In Matrix Procedures 11/2007 Emre S. Tasci S&C / MSE / 3mE / TUDelft Functions List (EF: Required External Functions)

• List MDiffElementEST[matrixIN_,varno_]
  Returns the list of the different elements in the (varno). row of the specified matrixIN 
  EF – NONE
• List MPolluteEST[mx_,row_,ratio_]
  Assigns a 0 or 1 (with equal probabilities) to the randomly selected "ratio" of the elements of the matrix "mx" and returns the new "polluted" matrix.If "mx" is a List, then "row" is not relevant.
  *EF – NONE;
• List MSelectEST[MatrixIN_,varno1_,varval1_, varno2_] 
  Returns the list of "varno2" variables from the "MatrixIN" where "varno1" values equal to "varval1" 
  EF – NONE / AppendRows from LinearAlgebra`MatrixManipulation` (Optional)
• List MSwapEST[MatrixIN_,row1_,row2_] 
  Swaps the rows "row1" and "row2" in matrix "MatrixIN" 
  EF – NONE

Important!!!

Assumed form of the MatrixIN: ; (i.e., values for the same variable are stored in ROWS, NOT in COLUMNS!)

Renderu – LaTeX parsing WordPress plugin

Adapting from Titus Barik’s “LaTeX Equations and Graphics in PHP” titled article from the Linux Journal magazine, I was able to write a plugin for WordPress that enables me to include LaTeX-type

 $\sum\limits_{j = 1}^m {p\left( X \right)H\left( {Y|X = x_i } \right)} $

in the form of a PNG file format as :

(Although there is problem with multi lined entries such as matrix)

Barik’s article explained the method for Linux, but it can easily be run on a Windows environment (as it is been running on my computer at this very moment). Just install a LaTeX distribution like MikTeX and an image manipulation package like ImageMagick and it’s ready!