Categorical spatial lag using the Graph

[sjsrey]

This has two changes from the creation of categorical spatial lags using W

1. categorical is now an option in _lag_spatial, to unify treatment of the lag.
2. This will raise an exception in the case where categorical=True , ties=raise, and ties are encountered.
   "Explicit is better than implicit."

[codecov]

Codecov Report

Attention: Patch coverage is 98.61111% with 1 line in your changes missing coverage. Please review.

Project coverage is 85.0%. Comparing base (bcabdbc) to head (82147e8).
Report is 18 commits behind head on main.

Additional details and impacted files

@@          Coverage Diff           @@
##            main    #716    +/-   ##
======================================
  Coverage   85.0%   85.0%            
======================================
  Files        141     145     +4     
  Lines      15203   15462   +259     
======================================
+ Hits       12924   13149   +225     
- Misses      2279    2313    +34     

Files	Coverage Δ
libpysal/graph/base.py	97.0% <ø> (-1.0%)	⬇️
libpysal/graph/tests/test_spatial_lag.py	100.0% <100.0%> (ø)
libpysal/graph/_spatial_lag.py	97.7% <97.4%> (-2.3%)	⬇️

... and 10 files with indirect coverage changes

[jGaboardi]

Three ruff errors (2 linting & 1 formatting) need to to fixed locally and re-pushed.

ruff.....................................................................Failed
- hook id: ruff
- exit code: 1

libpysal/graph/tests/test_spatial_lag.py:1:1: I001 [*] Import block is un-sorted or un-formatted
libpysal/graph/tests/test_spatial_lag.py:62:13: F841 Local variable `yl` is assigned to but never used
Found 2 errors.
[*] 1 fixable with the `--fix` option (1 hidden fix can be enabled with the `--unsafe-fixes` option).

ruff-format..............................................................Failed
- hook id: ruff-format
- files were modified by this hook

2 files reformatted, 151 files left unchanged

[martinfleis]

This needs to be propagated to base.py

libpysal/libpysal/graph/base.py

Line 1618 in 5bda115

def lag(self, y):

[martinfleis]

Two minor suggestions in tests.

As mentioned before, this needs to propagate to

libpysal/libpysal/graph/base.py

Lines 1618 to 1635 in 5bda115

	def lag(self, y):
	"""Spatial lag operator
	If weights are row standardized, returns the mean of each
	observation's neighbors; if not, returns the weighted sum
	of each observation's neighbors.
	Parameters
	----------
	y : array-like
	array-like (N,) shape where N is equal to number of observations in self.
	Returns
	-------
	numpy.ndarray
	array of numeric values for the spatial lag
	"""
	return _lag_spatial(self, y)

[ljwolf]

What would you think about dispatching to categorical lag if the type is categorical?

I can appreciate that this might make the lag type implicit, but if someone has cast the variable to a categorical already, I think we can infer that they need the appropriate lag function?

[martinfleis]

@ljwolf that is what we do on l. 87, no?

[martinfleis]

Just two minor nits on the docstring. Also, ruff complains at the moment. But once that is solved, happy to merge.

[martinfleis]

pre-commit.ci autofix