Hi List,
I'm using Mahout Logistic Regression for a prediction task. As a test, I try the classification task with one single feature, a categorical one with 26 levels.
When I run the Logistic regression on R or Python, I expect 25 coefficients (corresponding to 25 out of the 26 levels, due to the "contrast coding") + the intercept. However, when I run it on Mahout, I have 26 coefficients + the intercept. Is there any way to force the contrast coding on Mahout (i.e. consider one of the level as the default level)? Isn't there a risk of matrix singularity by considering the 26 levels in the logistic regression?
Let me know if it's not clear.Thanks in advance for your answers,
Aymen
I'm using Mahout Logistic Regression for a prediction task. As a test, I try the classification task with one single feature, a categorical one with 26 levels.
When I run the Logistic regression on R or Python, I expect 25 coefficients (corresponding to 25 out of the 26 levels, due to the "contrast coding") + the intercept. However, when I run it on Mahout, I have 26 coefficients + the intercept. Is there any way to force the contrast coding on Mahout (i.e. consider one of the level as the default level)? Isn't there a risk of matrix singularity by considering the 26 levels in the logistic regression?
Let me know if it's not clear.Thanks in advance for your answers,
Aymen
