Make DataVec's vertical

[johnmyleswhite]

At present DataVec's don't ever interact with DataMatrix's, so we haven't needed to be careful about the horizontal or vertical orientation of a DataVec. Our current show() method makes a DataVec look horizontal, but the structure should probably be vertical for consistency with Julia's standard vectors.

[HarlanH]

I'm not sure I agree with this. Julia vectors are vertical to reinforce the ordering of matrices, I think. That's not important for us to reinforce. And from the point of view of interactive data analysis, wasting all of that space doesn't sound like a good idea. On Nov 30, 2012 7:05 PM, "John Myles White" notifications@github.com wrote:

At present DataVec's don't ever interact with DataMatrix's, so we haven't needed to be careful about the horizontal or vertical orientation of a DataVec. Our current show() method makes a DataVec look horizontal, but the structure should probably be vertical for consistency with Julia's standard vectors.

— Reply to this email directly or view it on GitHubhttps://github.com/HarlanH/DataFrames.jl/issues/89.

[johnmyleswhite]

If DataVec's are horizontal, what direction does their transpose go in?

And if they're horizontal, why are they printed vertically inside of DataFrame's?

[HarlanH]

To me, direction for a DV is barely relevant. It's just an array. We can print it either way. But yes, a DF is vertical, because that's the standard for database table output, and because most useful DFs will have more rows than columns, so it looks better in that direction. For a DV, it looks better horizontally, I think. On Nov 30, 2012 7:25 PM, "John Myles White" notifications@github.com wrote:

If DataVec's are horizontal, what direction does their transpose go in?

And if they're horizontal, why are they printed vertically inside of DataFrame's?

— Reply to this email directly or view it on GitHubhttps://github.com/HarlanH/DataFrames.jl/issues/89#issuecomment-10909664.

[johnmyleswhite]

Ok. I don't have very strong feelings on this, but do think that verticality will turn out to be a helpful mnemonic when we have DataArray's. Let's revisit this then.

[HarlanH]

Ok. On Nov 30, 2012 7:31 PM, "John Myles White" notifications@github.com wrote:

Ok. I don't have very strong feelings on this, but do think that verticality will turn out to be a helpful mnemonic when we have DataArray's. Let's revisit this then.

— Reply to this email directly or view it on GitHubhttps://github.com/HarlanH/DataFrames.jl/issues/89#issuecomment-10909787.

[StefanKarpinski]

I rather feel like DataVecs should print like vectors. I know it seems like a waste of space, but I think it's right.

[johnmyleswhite]

For me the following code (which now is in my branch of DataFrames) settles the case for why we should make DataVec's vertical:

{DataVec(squeeze(m[:,i])) for i = 1:size(m, 2)}

That prints something that looks like an array, but the real "array" is actually the transpose of what you see on the screen when you print DataVec's horizontally.

[StefanKarpinski]

I feel somewhat strongly that making all vectorish things vertical seems like a good idea.

[johnmyleswhite]

I just changed this on my branch and like how it looks.

[HarlanH]

I'm outvoted. :) And in OSS, actually writing code is 9/10ths of the law.

[johnmyleswhite]

The tyranny of democracy wins again! Now that we've got basically functional DataMatrix objects, I think the visual consistency is going to be helpful. If we succeed at getting DataVec to inherit from AbstractVector we'll also inherit vertical printing by default.