pdeffebach

I think we should keep existing metadata of the destination always, and leave it up to the user to change the metadata. `:x = :y`, keep metadata. `:x = :x^2`...

Sorry for the delay on this. I'm with @nalimilan (I think). I would say ``` :x = :y ``` shouldn't forward metadata, if we are keeping things simple for now....

In Stata, ``` gen y = x ``` does not forward metadata. So that's where my intuition comes from. Stata has ``` replace x = x + 1 ``` which...

> * keep metadata of existing columns unchanged; > * new columns have no metadata. Yes. I think this is a clear and consistent rule. Of course, it allows for...

I don't think @bkamins needs to maintain the "purity" of DataFrames. Useability should take precedent and as I've argued in this thread above, being over-eager in destroying metadata would make...

FWIW, I just checked out the branch and built the docs. I think the API is great. Here are two helper functions I quickly wrote to make things a bit...

Bumping this, I ran into this today. I think we can add a keyword argument for preserving order without adding `leftjoin!`.

Ahh I forgot about that. Thanks.

I can't think of an easy way to mark just some columns as "whole column" references and others as not. The current implementation just takes the anonymous function created by...

``` @chain df begin @aside age = NamedArray( _.age, _.name ) @rtransform :Age_relative_to_Sally = :age - age["Sally"] end ``` This still has some performance issues, since `age["Sally"]` is called every...