Merge pull request #231 from JuliaMath/teh/news

Add NEWS about release 0.9

Author: timholy

NEWS.md

@@ -0,0 +1,28 @@
+# v0.9.0
+
+Breaking changes:
+
+- `gradient` and `hessian` are no longer exported; use `Interpolations.gradient` and
+  `Interpolations.hessian`.
+- `interpolate` objects now check bounds, and throw an error if you try to evaluate them
+  at locations beyond the edge of their interpolation domain; use `extrapolate` if you need out-of-bounds evaluation
+- For quadratic and cubic interpolation, `interpolate!` now returns an object whose axes
+  are narrowed by the amount of padding needed on the array edges. This preserves correspondence
+  between input indices and output indices. See https://julialang.org/blog/2017/04/offset-arrays
+  for more information.
+- The parametrization of some types has changed; this does not affect users of the "exported"
+  interface, but does break packages that performed manual construction of explicit types.
+
+Changes with deprecation warnings:
+
+- `itp[i...]` should be replaced with `itp(i...)`.
+- `OnGrid` and `OnCell` should now be placed inside the boundary condition (e.g., `Flat(OnGrid())`),
+  and should only be used for quadratic and cubic interpolation.
+- the extrapolation boundary condition `Linear` was changed to `Line`, to be consistent
+  with interpolation boundary conditions.
+
+Advance notice of future changes:
+
+- In future versions `itp[i...]` may be interpreted with reference to the parent array's
+  indices rather than the knots supplied by the user (relevant for `scale` and `Gridded`).
+  If you fix the existing deprecation warnings then you should be prepared for this change.

README.md

@@ -4,6 +4,8 @@
 [![PkgEval Status](http://pkg.julialang.org/badges/Interpolations_0.4.svg)](http://pkg.julialang.org/?pkg=Interpolations)
 [![Interpolations](http://pkg.julialang.org/badges/Interpolations_0.5.svg)](http://pkg.julialang.org/?pkg=Interpolations)
 
+**NEWS** v0.9 was a breaking release. See the [news](NEWS.md) for details on how to update.
+
 This package implements a variety of interpolation schemes for the
 Julia language.  It has the goals of ease-of-use, broad algorithmic
 support, and exceptional performance.