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Bayesian vs. Frequentist

This article provides good arguments from perspective of both sides:

[2008] Objections to Bayesian statistics (with discussion). {\em Bayesian Analysis}, to appear. (Andrew Gelman)
Rejoinder to discussion. (Andrew Gelman)

It is very nice to see a balanced view on the issue.

Bayesian vs. Frequentist

Visualizing MovieLens Rating Matrix

It is interesting to look at the visualization of the MovieLens Rating Matrix

Here is a random sub sample

 

 

Here is the Matlab's code:

% load data
% Multi-character delimiters are not supported;
% so we get columns with delimeters too
D = importdata('ratings.dat',':');

% load data into sparse matrix
X = sparse(D(:,3),D(:,1),D(:,5));

% plot the whole matrix
imagesc(X'); figure(gcf)

% plot random sampling of matrix
r1_idx = randint(1,100,[1,6040]);
r2_idx = randint(1,100,[1,3592]);
R = X(r2_idx,r1_idx);
imagesc(R'); figure(gcf)

 

MovieLens movie's popularity plot/graph (Matlab)

This is the code to load the MovieLens dataset into Matlab and to do some plotting:

The simpleset way of loading the dataset is via ImportWizard

All I want to do is to plot a graph where x-axis is movie id and y-axis is popularity (number of ratings).

 

% column of movie_ids
m = ratings(:,3);

% 1:3592 = movie_ids
[freq,xout] = hist(m,(1:3592));

% plotting sorted by popularity
plot( sort(freq));

 

The result is a nice power law (long tailed) distribution.

AdWords API: java.lang.NullPointerException

I had a rather strange error:

java.lang.NullPointerException
    at com.google.api.adwords.v12.KeywordToolServiceSoapBindingStub.getKeywordVariations_aroundBody1$advice(KeywordToolServiceSoapBindingStub.java:146)
    at com.google.api.adwords.v12.KeywordToolServiceSoapBindingStub.getKeywordVariations(KeywordToolServiceSoapBindingStub.java:1)
    at org.hrstc.termexpansion.impl.google.GetKeywordVariations.main(GetKeywordVariations.java:69)
 

Solution:

http://groups.google.com/group/adwords-api/browse_thread/thread/77baa14b...

Examples provided in the API documentation are incorect:

  • using the wrong package names
  • not working even after fixing some minor errors

As the above blog suggests it is much better just to use library from http://code.google.com/p/google-api-adwords-java/ and the corresponding examples

 

 

Location of jdesktop.jar

NetBeans uses jdesktop but does not deploy it properly so you have to add it the library by yourself.

Keywords: org-jdesktop-layout.jar download location path NetBeans org.jdesktop.application import cannot be resolved class not found

It is located in your NetBeans projet folder:

YourProject/dist/lib/appframework-1.0.3.jar

 

Location

neil@DS:~$ find  -name '*jdesktop*.jar'
./netbeans-6.1/platform8/modules/org-jdesktop-layout.jar
./netbeans-6.1/platform8/modules/locale/org-jdesktop-layout_pt_BR.jar
./netbeans-6.1/platform8/modules/locale/org-jdesktop-layout_zh_CN.jar
./netbeans-6.1/platform8/modules/locale/org-jdesktop-layout_ja.jar
./netbeans-6.1/java2/modules/org-jdesktop-beansbinding.jar
./netbeans-6.1/java2/modules/locale/org-jdesktop-beansbinding_pt_BR.jar
./netbeans-6.1/java2/modules/locale/org-jdesktop-beansbinding_ja.jar
./netbeans-6.1/java2/modules/locale/org-jdesktop-beansbinding_zh_CN.jar
 

 

Keywords

package org.jdesktop.layout does not exist
        org.jdesktop.layout.GroupLayout layout = new org.jdesktop.layout.GroupLayout(this);
 

UML for NetBeans 6.1

UML for NetBeans 6.1 EE

In my opinion UML should have been included in the default install (to promote good engineering/coding practices).  It is not, so here what you need to do to install it:

1) click on the menu: Tools/Plugins
2) select "Available Plugins" tab
3) select UML plugin
4) install

 

Ubuntu / Java lost focus issues

Problem: suddenly java applications such as Eclipse, NetBeans lost the text cursor focus (e.g. when performing auto complete, search, etc).  A temporary fix was to switch alt-tab between the windows and then the focus would be regained.

Solution: In my case it seem to have been caused by SCIM.  To fix it System/Administration/Language Support then uncheck the "Enable support to enter complex characters".

Keywords: ubuntu hardy heron java lost focus netbeans eclipse switch problem compiz SCIM

Work Log

Implementing VOI Analyzer

TODO

Result
Reduce itteration for influenceAL from 7min -> 1 sec

Solution

Estimate preferences in a batch manner:
Estimating the ratings:
    for each user
        newRatings (items rated by the user) = scaled by the user's correlation

Problem

Influence AL takes a very long time

It takes 7 min to estimate all the preferences

Apr 27, 2008 11:13:15 AM com.planetj.taste.impl.recommender.VOIUserBasedRecommender estimatePreferences
INFO: Start.
Apr 27, 2008 11:20:20 AM com.planetj.taste.impl.recommender.VOIUserBasedRecommender estimatePreferences
INFO: FINISH.
 

 

Optimizing Influence-based AL

Right now selecting an AL item, takes 2 hours - thats a little bit too long :)

Trying to optimize it

 

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