Addition of links on the filling NaN values.

README.md

@@ -27,6 +27,18 @@ This software also uses [CMake](https://cmake.org/) to configure the project
 and [Googletest](https://github.com/google/googletest) to perform unit testing
 of the library kernel.
 
+## Fill undefined values
+
+The undefined values in the grids do not allow interpolation of values located
+in the neighborhood. This behavior is a concern when you need to interpolate
+values near the mask of some fields. The library provides utilities to fill the
+undefined values:
+
+* `loess` to fill the undefined values on the boundary between the defined/undefined
+  values using local regression.
+* `gauss_seidel` to fill all undefined values in a grid using the Gauss-Seidel
+  method by relaxation.
+
 ## Geographic indexers
 
 ### N-Dimensional Grids

docs/source/about.rst

@@ -13,6 +13,16 @@ This first version can interpolate 2D fields using :py:class:`bivariate
 <pyinterp.trivariate.Trivariate>` interpolators and :py:class:`unstructured
 grids <pyinterp.rtree.RTree>`.
 
+The undefined values in the grids do not allow interpolation of values located
+in the neighborhood. This behavior is a concern when you need to interpolate
+values near the mask of some fields. The library provides utilities to fill the
+undefined values:
+
+* :py:func:`loess <pyinterp.fill.loess>` to fill the undefined values on the
+  boundary between the defined/undefined values using local regression
+* :py:func:`gauss_seidel <pyinterp.fill.gauss_seidel>` to fill all undefined
+  values (NaN) in a grid using the Gauss-Seidel method by relaxation. 
+
 The library core is written in C++ using the `Boost C++ Libararies
 <https://www.boost.org/>`_, `Eigen3 <http://eigen.tuxfamily.org/>`_, `GNU
 Scientific Library <https://www.gnu.org/software/gsl/>`_ and `pybind11

docs/source/examples.rst

@@ -261,7 +261,7 @@ Gauss-Seidel
 ############
 
 The :py:func:`second <pyinterp.fill.gauss_seidel>` method consists of replacing
-all undefined values (Nan) in a grid using the Gauss-Seidel method by
+all undefined values (NaN) in a grid using the Gauss-Seidel method by
 relaxation. This `link
 <https://math.berkeley.edu/~wilken/228A.F07/chr_lecture.pdf>`_ contains more
 information on the method used.

src/pyinterp/bicubic.py

@@ -53,7 +53,7 @@ def bicubic(grid2d: grid.Grid2D,
         bounds_error (bool, optional): If True, when interpolated values
             are requested outside of the domain of the input axes (x,y), a
             :py:class:`ValueError` is raised. If False, then value is set
-            to Nan. Default to ``False``
+            to NaN. Default to ``False``
 
         num_threads (int, optional): The number of threads to use for the
             computation. If 0 all CPUs are used. If 1 is given, no parallel

src/pyinterp/bivariate.py

@@ -33,7 +33,7 @@ def bivariate(grid2d: grid.Grid2D,
         bounds_error (bool, optional): If True, when interpolated values
             are requested outside of the domain of the input axes (x,y), a
             :py:class:`ValueError` is raised. If False, then value is set
-            to Nan. Default to ``False``
+            to NaN. Default to ``False``
         num_threads (int, optional): The number of threads to use for the
             computation. If 0 all CPUs are used. If 1 is given, no parallel
             computing code is used at all, which is useful for debugging.

src/pyinterp/core/include/pyinterp/bivariate.hpp

@@ -214,7 +214,7 @@ Interpolate the values provided on the defined bivariate function.
       used to interpolate.
     bounds_error (bool, optional): If True, when interpolated values are
       requested outside of the domain of the input axes (x,y), a ValueError
-      is raised. If False, then value is set to Nan.
+      is raised. If False, then value is set to NaN.
     num_threads (int, optional): The number of threads to use for the
         computation. If 0 all CPUs are used. If 1 is given, no parallel
         computing code is used at all, which is useful for debugging.

src/pyinterp/core/include/pyinterp/trivariate.hpp

@@ -135,7 +135,7 @@ Interpolate the values provided on the defined trivariate function.
         used to interpolate values on the surface (x, y).
     bounds_error (bool, optional): If True, when interpolated values are
       requested outside of the domain of the input axes (x,y,z), a ValueError
-      is raised. If False, then value is set to Nan.
+      is raised. If False, then value is set to NaN.
     num_threads (int, optional): The number of threads to use for the
         computation. If 0 all CPUs are used. If 1 is given, no parallel
         computing code is used at all, which is useful for debugging.

src/pyinterp/core/module/bicubic.cpp

@@ -169,7 +169,7 @@ nearest-neighbor interpolation.
         :py:data:`pyinterp.core.Axis.Boundary.kUndef`
     bounds_error (bool, optional): If True, when interpolated values are
         requested outside of the domain of the input axes (x,y), a ValueError
-        is raised. If False, then value is set to Nan.
+        is raised. If False, then value is set to NaN.
     num_threads (int, optional): The number of threads to use for the
         computation. If 0 all CPUs are used. If 1 is given, no parallel
         computing code is used at all, which is useful for debugging.

src/pyinterp/trivariate.py

@@ -35,7 +35,7 @@ def trivariate(grid3d: grid.Grid3D,
         bounds_error (bool, optional): If True, when interpolated values
             are requested outside of the domain of the input axes (x,y), a
             :py:class:`ValueError` is raised. If False, then value is set
-            to Nan. Default to ``False``
+            to NaN. Default to ``False``
         num_threads (int, optional): The number of threads to use for the
             computation. If 0 all CPUs are used. If 1 is given, no parallel
             computing code is used at all, which is useful for debugging.

src/pyinterp/version.py

@@ -6,8 +6,8 @@
 
 def release(full: bool = False) -> str:
     """Returns the software version number"""
-    # c133d9af2aee7c2bd37212fc8cd757a695b3cc5e
+    # ddab30ba4cf5b5d44a049f62741801df8d44886e
     result = "0.0.2"
     if full:
-        result += " (12 July 2019)"
+        result += " (29 July 2019)"
     return result