My data-set has 23377 instances for training (7792 for testing). The dimension of the data is approximately 28000. Each instance represents a document and the target variable is the age of the document's author. I want to perform a regression over the data with all the features (± 28000) and/or do some selection feature process to work with a regression method afterward.
What I was thinking to do is 1) using ridge-regression (with the ± 28000 features) and 2) perform a feature selection method to see the impact of dimension reduction with ridge-regression. Ridge-regression over the 28000 features is taking a very long time; it is still running in a server (I use Sklearn, Python). After that I tried with SVR (Support Vector Regression) which is taking a long time too. For feature selection I was using χ2 (CHI2) over the same data for a classification problem but for doing regression I have to use other method. The method I want to use is Lasso (http://goo.gl/2DzM0K).
Is there other regression method for this high dimensional problem? Or Can you recommend a method to do a feature selection?