roots docstring reworked

pyerrors/roots.py

@@ -1,20 +1,31 @@
-#!/usr/bin/env python
-# coding: utf-8
-
 import scipy.optimize
 from autograd import jacobian
 from .obs import derived_observable, pseudo_Obs
 
 
 def find_root(d, func, guess=1.0, **kwargs):
-    """Finds the root of the function func(x, d) where d is an Obs.
+    r'''Finds the root of the function func(x, d) where d is an `Obs`.
 
     Parameters
     -----------------
-    d -- Obs passed to the function.
-    func -- Function to be minimized. Any numpy functions have to use the autograd.numpy wrapper
-    guess -- Initial guess for the minimization.
-    """
+    d : Obs
+        Obs passed to the function.
+    func : object
+        Function to be minimized. Any numpy functions have to use the autograd.numpy wrapper.
+        Example:
+        ```python
+        import autograd.numpy as anp
+        def root_func(x, d):
+            return anp.exp(-x ** 2) - d
+        ```
+    guess : float
+        Initial guess for the minimization.
+
+    Returns
+    -------
+    Obs
+        `Obs` valued root of the function.
+    '''
     root = scipy.optimize.fsolve(func, guess, d.value)
 
     # Error propagation as detailed in arXiv:1809.01289