test: add initial test of optimizer

pyproject.toml

@@ -81,3 +81,9 @@ exclude = '''
   | tests/data
 )/
 '''
+
+[tool.pytest.ini_options]
+markers = [
+    "slow: marks tests as slow (deselect with '-m \"not slow\"')",
+]
+testpaths = ["tests"]

src/diffpy/snmf/__init__.py

@@ -18,6 +18,11 @@
 # package version
 from diffpy.snmf.version import __version__
 
+# public API
+from .snmf_class import SNMFOptimizer
+
+__all__ = ["__version__", "SNMFOptimizer"]
+
 # silence the pyflakes syntax checker
 assert __version__ or True
 

src/diffpy/snmf/snmf_class.py

@@ -1,9 +1,10 @@
 import cvxpy as cp
 import numpy as np
-from plotter import SNMFPlotter
 from scipy.optimize import minimize
 from scipy.sparse import coo_matrix, diags
 
+from .plotter import SNMFPlotter
+
 
 class SNMFOptimizer:
     """An implementation of stretched NMF (sNMF), including sparse stretched NMF.