Re: [Scikit-learn-general] How to approach "Sum of True and False Positives = 0"

2013-10-17 Thread Joel Nothman
It's not a very clear error message, and PR#2278 corrected that. "The sum of true positives and false positives" for some label l is the number of times your system predicts l in the fold's test data. So it's certainly possible that this will occur, no matter what CV strategy you take. A stratified

Re: [Scikit-learn-general] How to approach "Sum of True and False Positives = 0"

2013-10-17 Thread Olivier Grisel
2013/10/17 Josh Wasserstein : > Hi Joel and others, > > Sorry, but I am still confused.. If I am using stratified shuffle splitting, > shouldn't I always have some positives in the testing set (I have positives > in the full dataset)? The message says: "The sum of true positives and false > positiv

Re: [Scikit-learn-general] How to approach "Sum of True and False Positives = 0"

2013-10-17 Thread Josh Wasserstein
Hi Joel and others, Sorry, but I am still confused.. If I am using *stratified shuffle splitting *, shouldn't I always have *some positives in the testing set (I have positives in the full dataset)*? The message says: "The sum of true positives and false positives (in other words total # of posit

Re: [Scikit-learn-general] Contributing code

2013-10-17 Thread Olivier Grisel
2013/10/16 Carlos Aspillaga : > Hello guys, > > I've been using scikit-learn for a while and I would like to contribute some > new functionalities. I have them implemented in other languages, but not in > python (yet...) > To start, I would love to implement some classic Feature Selection > Algorit

Re: [Scikit-learn-general] Contributing code

2013-10-17 Thread Jacob Vanderplas
Hi Carlos, Welcome! We'd love to have you contribute. You can start by reading through the developers guide on our website, and following the suggestions there: http://scikit-learn.org/stable/developers/ Feel free to ask here if any questions come up, Jake On Wed, Oct 16, 2013 at 2:09 PM, Ca

[Scikit-learn-general] Contributing code

2013-10-17 Thread Carlos Aspillaga
Hello guys, I've been using scikit-learn for a while and I would like to contribute some new functionalities. I have them implemented in other languages, but not in python (yet...) To start, I would love to implement some classic Feature Selection Algorithms (dimensionality reduction) that I have