Fix scalar input for grads.

CHANGELOG

 Changelog
 =========
+2021-10-26 v1.1.2
+-----------------
+  * Adapt grad functions to scalar input 
+
 2021-10-20 v1.1.1
 -----------------
   * Correct documentation of equi_sph

pymagglobal/__init__.py

@@ -46,4 +46,4 @@ from pymagglobal.core import local_curve, dipole_series, file2splines, \
     Model
 from pymagglobal import utils
 
-__version__ = '1.1.1'
+__version__ = '1.1.2'

pymagglobal/utils.py

@@ -42,26 +42,47 @@ def _nicelabel(label):
 def grad_d(n, e, z):
     '''Calculate the gradient of D.
     '''
+    n = np.atleast_1d(n)
+    e = np.atleast_1d(e)
+    z = np.atleast_1d(z)
     res = np.column_stack((-e, n, np.zeros_like(n)))
     res /= (n**2 + e**2)[:, np.newaxis]
+
+    if res.shape[0] == 1:
+        res = res.flatten()
+
     return np.rad2deg(res)
 
 
 def grad_i(n, e, z):
     '''Calculate the gradient of I.
     '''
+    n = np.atleast_1d(n)
+    e = np.atleast_1d(e)
+    z = np.atleast_1d(z)
     res = -np.column_stack((n, e, z)) \
         * z[:, np.newaxis]
     res /= (n**2 + e**2 + z**2)[:, np.newaxis]
     res[:, 2] += 1.
     res /= np.sqrt(n**2 + e**2)[:, np.newaxis]
+    
+    if res.shape[0] == 1:
+        res = res.flatten()
+
     return np.rad2deg(res)
 
 
 def grad_f(n, e, z):
+    n = np.atleast_1d(n)
+    e = np.atleast_1d(e)
+    z = np.atleast_1d(z)
     '''Calculate the gradient of F '''
     res = np.column_stack((n, e, z))
     res /= np.sqrt(n**2 + e**2 + z**2)[:, np.newaxis]
+
+    if res.shape[0] == 1:
+        res = res.flatten()
+
     return res