Stratified Sampling

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What version of the product are you using? On what operating system?

Windows-Precompiled-RF_MexStandalone-v0.02-\RF_MexStandalone-v0.02-precompiled

If I want to use Stratified Sampling for splitting data into testing and 
training sets in this randomforest package, can you please suggest anything?

Original issue reported on code.google.com by first.2...@gmail.com on 1 Nov 2012 at 7:07

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oh i am so sorry. i sortof missed this issue. 

let me look at it and get back to you in a couple of days.

Original comment by abhirana on 25 Nov 2012 at 9:29

• Changed state: Started

[GoogleCodeExporter]

hi, is the internal oob error process is stratified? 

i have the following six classes with the available number of samples. ( with a 
372 feature vector)

class1 150 
class2 102 
class3 109
class4 94 
Class5 208 
Class6 58  total samples 721.

for testing i have used 5 fold stratified cross validation. 

Any special suggestions regarding my data? 
Is I have something to do with the classwt or cutoff option?

regards,
Ihtesham

Original comment by ihtesham...@gmail.com on 1 Dec 2012 at 10:26

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there is one more related questions . in your demo code you write 
extra_options.strata, is this related to my question in comment 2.

regards,
Ihtesham

Original comment by ihtesham...@gmail.com on 3 Dec 2012 at 1:19

[GoogleCodeExporter]

hi @Ihtesham and the OP

sorry for my late reply.

i am still not finished debugging the strata code, i should have something by 
the end of this week. thanks

@Ihtesham, yup it has to do with the extr_options.strata (not yet done) where 
sampling can be done according to how the labels are distributed.

Original comment by abhirana on 11 Dec 2012 at 10:53

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thanks for your valuable reply. I am waiting for an update. 

Original comment by ihtesham...@gmail.com on 12 Dec 2012 at 12:51

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hello,

i added support for stratified sampling in the svn source. Look at the 
tutorial_ClassRF.m file for the last two examples for how to do stratified 
sampling.

i hope it works. do tell me if you encounter any problems or have any 
questions. 

thanks

Original comment by abhirana on 19 Dec 2012 at 8:31