https://github.com/GPflow/GPflow
Revision deb4508578f7223fa1ad5e3b6458626c4b41ef09 authored by Eric Hammy on 17 October 2019, 14:46:42 UTC, committed by GitHub on 17 October 2019, 14:46:42 UTC
1. Fix hidden bug in SGPR
2. Add the  sgpr.compute_qu method from gpflow1

1. [Bug]. SGPR likelihoods were previously using full rank matrices instead of
diagonal ones in both upper bound and likelihood calculation. Ie `Kdiag`
was not "diag". 

This error was being masked by the intentional deactivation of tests
comparing to the SGPR to the GPR, and what appears to be a hack to make
tests working on the upper bound case.

2. [Migration]. Fixing the above broke another test, originally used for
 sgpr.compute_qu.  The method sgpr.compute_qu had not been migrated 
from gpflow1, and a test that was meant to check it had been patched up to pass,
erroneously.

After speaking to @markvdw, concluded this method is useful, in
particular to compare to SVGP model. The test has been patched up and
the method ported to gpflow2.
1 parent 3b2a2ee
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Tip revision: deb4508578f7223fa1ad5e3b6458626c4b41ef09 authored by Eric Hammy on 17 October 2019, 14:46:42 UTC
Fix hidden bug in SGPR (#1106)
Tip revision: deb4508
GLOSSARY.md
## Glossary

GPflow does not always follow standard Python naming conventions,
and instead tries to apply the notation in the relevant GP papers.\
The following is the convention we aim to use in the code.

---

<dl>
  <dt>GPR</dt>
  <dd>Gaussian process regression</dd>

  <dt>SVGP</dt>
  <dd>stochastic variational inference for Gaussian process models</dd>

  <dt>Shape constructions [..., A, B]</dt>
  <dd>the way of describing tensor shapes in docstrings and comments. Example: <i>[..., N, D, D]</i>, this is a tensor with an arbitrary number of leading dimensions indicated using the ellipsis sign, and the last two dimensions are equal</dd>

  <dt>X</dt>
  <dd>(and variations like Xnew) refers to input points; always of rank 2, e.g. shape <i>[N, D]</i>, even when <i>D=1</i></dd>

  <dt>Y</dt>
  <dd>(and variations like Ynew) refers to observed output values, potentially with multiple output dimensions; always of rank 2, e.g. shape <i>[N, P]</i>, even when <i>P=1</i></dd>

  <dt>Z</dt>
  <dd>refers to inducing points</dd>

  <dt>M</dt>
  <dd>stands for the number of inducing features (e.g. length of Z)</dd>

  <dt>N</dt>
  <dd>stands for the number of data or minibatch size in docstrings and shape constructions</dd>

  <dt>P</dt>
  <dd>stands for the number of output dimensions in docstrings and shape constructions</dd>

  <dt>D</dt>
  <dd>stands for the number of input dimensions in docstrings and shape constructions</dd>
</dl>
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