fix e-notation bug

Author: dbatten5

src/arraytex/api.py

@@ -82,8 +82,8 @@ def to_tabular(
 
     Raises:
         TooManyDimensionsError: when the supplied array has more than 2 dimensions
-        DimensionMismatchError: when there are mismatched column identifiers and
-            dimensions
+        DimensionMismatchError: when there is a mismatch between column items and number
+            of columns, or column index items and number of rows
     """
     n_dims = len(arr.shape)
 

src/arraytex/utils.py

@@ -61,7 +61,7 @@ def num_formatter(x: Union[np.int64, np.float64, np.float32]) -> str:
     )
 
     if num_format and "e" in num_format:
-        pattern = r"e(-?\d+)"
+        pattern = r"e([\+-]?\d+)"
         replace = r"\\mathrm{e}{\g<1>}"
         if scientific_notation:
             replace = r" \\times 10^{\g<1>}"

tests/test_api.py

@@ -87,6 +87,20 @@ def test_e_notation(self) -> None:
             == r"""\begin{bmatrix}
 1.00\mathrm{e}{-03} & 2.00\mathrm{e}{-03} & 3.00\mathrm{e}{-03} \\
 4.00\mathrm{e}{-03} & 5.00\mathrm{e}{-03} & 6.00\mathrm{e}{-03} \\
+\end{bmatrix}"""
+        )
+
+    def test_e_notation_positive(self) -> None:
+        """Scientific E notation can be selected with positive powers."""
+        mat = np.arange(6).reshape(2, 3)
+
+        out = to_matrix(mat, num_format=".2e")
+
+        assert (
+            out
+            == r"""\begin{bmatrix}
+0.00\mathrm{e}{+00} & 1.00\mathrm{e}{+00} & 2.00\mathrm{e}{+00} \\
+3.00\mathrm{e}{+00} & 4.00\mathrm{e}{+00} & 5.00\mathrm{e}{+00} \\
 \end{bmatrix}"""
         )