Fix docstrings with incorrect anchor order (#90)

* Updated docstrings and error message to correctly represent anchor order

* Updated docstrings to maintain consistency: 'temperature-pressure pairs' now uses hypen instead of ',' or 'and'

* Updated docstrings in to maintain consistency: updated further references

* Made docstrings easier to read

* Update tephi/isopleths.py

---------

Co-authored-by: Bill Little <bill.little@metoffice.gov.uk>

tephi/__init__.py

@@ -595,9 +595,9 @@ def __init__(
             A :class:`tephi.Locator` instance or a numeric step size
             for the dry adiabat lines.
         * anchor:
-            A sequence of two pressure, temperature pairs specifying the extent
-            of the tephigram plot in terms of the bottom left hand corner and
-            the top right hand corner. Pressure data points must be in units of
+            A sequence of two (pressure, temperature) pairs specifying the extent
+            of the tephigram plot in terms of the bottom right-hand corner, and
+            the top left-hand corner. Pressure data points must be in units of
             mb or hPa, and temperature data points must be in units of degC.
 
         For example:
@@ -801,9 +801,9 @@ def __init__(
                 or len(self._anchor) != 2
             ):
                 msg = (
-                    "Invalid anchor, expecting [(bottom-left-pressure, "
-                    "bottom-left-temperature), (top-right-pressure, "
-                    "top-right-temperature)]"
+                    "Invalid anchor, expecting [(bottom-right-pressure, "
+                    "bottom-right-temperature), (top-left-pressure, "
+                    "top-left-temperature)]"
                 )
                 raise ValueError(msg)
             (
@@ -839,7 +839,7 @@ def plot(self, data, **kwargs):
 
         Args:
 
-        * data: pressure and temperature pair data points.
+        * data: (pressure, temperature) pair data points.
 
         .. note::
             All keyword arguments are passed through to

tephi/isopleths.py

@@ -140,7 +140,7 @@ def _wet_adiabat_gradient(min_temperature, pressure, temperature, dp):
         calculate the gradient difference.
 
     Returns:
-        The gradient change as a pressure, potential temperature value pair.
+        The gradient change as a (pressure, potential-temperature) value pair.
 
     """
 
@@ -418,7 +418,7 @@ def __init__(self, data, axes):
         if self.data.ndim != 2 or self.data.shape[-1] != 2:
             msg = (
                 "The environment profile data requires to be a sequence "
-                "of pressure, temperature value pairs."
+                "of (pressure, temperature) value pairs."
             )
             raise ValueError(msg)
         self.axes = axes