[WIP] Unit test firm.py

[hdoupe]

So far, I've written unit tests for test_get_r, test_get_w, test_get_Y, and test_get_L.

For test_get_r, test_get_w, and test_get_Y, I chose values for the parameters that seemed realistic and made the calculations easier. I then checked to make sure the expected and actual values were equal.

For test_get_L, I looped over the values of the matrices to do the multiplication. I wasn't sure about the behavior of Python's element wise matrix multiplication. So, I used the looping method because it is much easier to understand. That way we can make sure the matrix multiplication method is doing what we expect it to do.

Also, I'm confused about the dimensions of the matrices that test_get_L expects when the TPI method is used. Are n and e a list of matrices of length T where each matrix is s x j?

I'm working on the remaining functions now. I welcome all feedback.

[jdebacker]

@hdoupe I think the looping is a good idea since there may be array broadcasting errors in the vectorized code.

Re the dimensions - yes, when get_L() is called from the TPI solution method, it gets passed 3 dimensional arrays. n has dimensions [time, age, ability] so it might be as big as [T+S, S, J] (though for some parts of the time path, the first two dimensions are smaller). The matrix e has dimensions [age, ability] but is tiled in the time path so that it has the same dimensions as the other objects it interacts with in get_L and other functions.

[hdoupe]

@jdebacker said

Re the dimensions - yes, when get_L() is called from the TPI solution method, it gets passed 3 dimensional arrays. n has dimensions [time, age, ability] so it might be as big as [T+S, S, J] (though for some parts of the time path, the first two dimensions are smaller). The matrix e has dimensions [age, ability] but is tiled in the time path so that it has the same dimensions as the other objects it interacts with in get_L and other functions.

Ok that makes sense.

What dimensions are you expecting when get_L returns? Right now, I'm getting a scalar back from get_L when method="SS" and a vector of length T when method="TPI"

[jdebacker]

@hdoupe says:

What dimensions are you expecting when get_L returns? Right now, I'm getting a scalar back from get_L when method="SS" and a vector of length T when method="TPI"

That's correct.

[PeterDSteinberg]

Hi @hdoupe - I'm not familiar enough with the subject matter to comment on the math directly, but this looks like good py.test style of unit tests.

[hdoupe]

@PeterDSteinberg Thanks for the review.

@jdebacker @rickecon What do you think of these tests? Are you OK with the values that I chose to test these functions? Are there any other tests that you want me to add for the firms module?

[jdebacker]

@hdoupe Let's make delta_tau something just a bit greater than delta. So if delta =0.25, let's make delta_tau 0.35

[jdebacker]

delta needs to be in [0, 1]. Try 0.15.

[jdebacker]

delta_tau also needs to be in [0, 1]. Try delta * 0.2.

[jdebacker]

Testing with tau_b > 0 above, so this is another good check. But wouldn't want to only test with tau_b = 0.

[hdoupe]

@PeterDSteinberg do you know what's causing the build to fail? It looks like it can't find taxcalc package version 0.8.3?

[EDIT] Nevermind, it looks like the build was successful on the second commit.

[jdebacker]

@hdoupe How is this PR looking? Ready for merge?

[hdoupe]

@jdebacker I think it's ready to merge. I used the parameters that you suggested. Are you satisfied with the changes?

[jdebacker]

Yes. Thanks @hdoupe. Merging now.