Format __init__ imports, avoid unnecessary spider log-y errors

Author: morganjwilliams

pyrolite/__init__.py

@@ -12,16 +12,14 @@
 
 import matplotlib.style
 
-from .util.log import Handle
-from .util.plot.style import _export_mplstyle  # this import adds the style used below
-
-logger = Handle(__name__)
-
 # initialise pandas accessors
 from .comp import pyrocomp  # noqa: E402
 from .geochem import pyrochem  # noqa: E402
 from .plot import pyroplot  # noqa: E402
+from .util.log import Handle
+from .util.plot.style import _export_mplstyle  # this import adds the style used below
 
+logger = Handle(__name__)
 
 def load_extensions(base="pyrolite_", replace=["util"]):
     """

pyrolite/plot/spider.py

@@ -257,18 +257,22 @@ def spider(
         # set the y range to lock to the outermost log-increments
         _ymin, _ymax = np.nanmin(arr), np.nanmax(arr)
 
-        if unity_line:
+        if unity_line:  # unity line is added at 1 - so may alter the total range
             _ymin, _ymax = min(_ymin, 1.0), max(_ymax, 1.0)
 
         if logy:
             # at 5% range in log space, and clip to nearest 'minor' tick
+            # except in the case where (logmin - 0.05 * logy_rng) <= 0
+            # (to avoid errors on log-scaled plots)
             logmin, logmax = np.log10(_ymin), np.log10(_ymax)
             logy_rng = logmax - logmin
 
             low, high = 10 ** np.floor(logmin), 10 ** np.floor(logmax)
-
+           
             _ymin, _ymax = (
-                np.floor(10 ** (logmin - 0.05 * logy_rng) / low) * low,
+                np.floor(10 ** (logmin - 0.05 * logy_rng) / low) * low
+                if (logmin - 0.05 * logy_rng) > 0
+                else low,
                 np.ceil(10 ** (logmax + 0.05 * logy_rng) / high) * high,
             )
         else: