fix python 3.7 build on travis (#634)

* update try python 3.7

* 3.7dev

* new resize operation

* whats new, comment

Author: wholmgren

docs/sphinx/source/whatsnew/v0.6.1.rst

@@ -70,6 +70,7 @@ Bug fixes
 * Fix error in :func:`pvlib.clearsky.detect_clearsky` (:issue:`506`)
 * Fix documentation errors when using IPython >= 7.0.
 * Fix error in :func:`pvlib.modelchain.ModelChain.infer_spectral_model` (:issue:`619`)
+* Fix error in ``pvlib.spa`` when using Python 3.7 on some platforms.
 
 
 Testing

pvlib/spa.py

@@ -255,19 +255,16 @@ def nocompile(*args, **kwargs):
         [[4.0, 2.56, 6283.08]])
 }
 
-
-TABLE_1_DICT['L1'].resize((64, 3))
-TABLE_1_DICT['L2'].resize((64, 3))
-TABLE_1_DICT['L3'].resize((64, 3))
-TABLE_1_DICT['L4'].resize((64, 3))
-TABLE_1_DICT['L5'].resize((64, 3))
-
-TABLE_1_DICT['B1'].resize((5, 3))
-
-TABLE_1_DICT['R1'].resize((40, 3))
-TABLE_1_DICT['R2'].resize((40, 3))
-TABLE_1_DICT['R3'].resize((40, 3))
-TABLE_1_DICT['R4'].resize((40, 3))
+resize_mapping = {
+    'L1': (64, 3), 'L2': (64, 3), 'L3': (64, 3), 'L4': (64, 3), 'L5': (64, 3),
+    'B1': (5, 3), 'R1': (40, 3), 'R2': (40, 3), 'R3': (40, 3), 'R4': (40, 3)}
+
+# make arrays uniform size for efficient broadcasting in numba, fill with 0s
+# np.resize does not work because it fills with repeated copies
+for key, dims in resize_mapping.items():
+    new_rows = dims[0] - TABLE_1_DICT[key].shape[0]
+    TABLE_1_DICT[key] = np.append(TABLE_1_DICT[key], np.zeros((new_rows, 3)),
+                                  axis=0)
 
 
 HELIO_LONG_TABLE = np.array([TABLE_1_DICT['L0'],