AndraD questions

• awk: how to extract from file A the columns with indexes specified in file B?
• PCA in R: prcomp and confidence ellipses
• Rails feedback form: How to get the url for the current page?
• Postgres in Conda Environment (Ubuntu 14.04)
• principal component analysis (PCA) in R: which function to use?
• No route matches [GET] "/signout"
• wysihtml5: Copying text from a word document to the editor
• heroku pgbackups:restore: Invalid dump format
• Backbone model.destroy(): Is explicit removal from collection necessary?
• Twitter Bootstrap Tooltip: flickers when placed on top of button, but works fine when placed at the left/right/bottom

AndraD answers