Merge branch 'changelog'

This merge starts the development cycle of the next major release by clearing
the change log.

CHANGELOG

@@ -3,193 +3,3 @@ CHANGELOG
 Nutils is being actively developed and the API is continuously evolving.
 The following overview lists user facing changes as well as newly added
 features in inverse chronological order.
-
-
-NEW: SI module for physical units
-
-The SI module provides a framework for checking the dimensional consistency of
-a formulation at runtime, as well as tools to convert between different units
-for post processing. Extensive documentation can be found in the docstring of
-the SI module. The framework can be seen in action in the cahnhilliard example,
-with more examples to be converted in future.
-
-
-NEW: nearest-neighbour interpolation in sample.asfunction, sample.basis
-
-The sample methods `asfunction` and `basis` have a new interpolation argument
-that take the string values "none" (default) or "nearest". The latter activates
-a new mode that allows evaluation of sampled data on other samples than the
-original by selecting the point that is closest to the target.
-
-
-FIXED: locate points on trimmed topologies with the skip_missing flag set
-
-The `locate` method has a `skip_missing` argument that instructs the method to
-silently drop points that can not be located on the topology. This setting was
-partially ignored by trimmed topologies which could lead to a `LocateError`
-despite the flag being set. This issue is now fixed.
-
-
-CHANGED: solve, solve_withinfo arguments
-
-Solver methods newton, minimize and pseudotime have their function signature
-slightly changed: 1. The tol argument (used to define the stop criterion) has
-been made mandatory. As the default value used to be 0 - an unreacheable value
-in practice - the argument was effectively mandatory already, which this change
-formalizes. 2. The maxiter argument was off by 1, leading maxiter=n to accept
-n+1 iterations. This mistake is now fixed, which may break applications that
-relied on the former erroneous behaviour.
-
-
-NEW: function.linearize
-
-Similar to `derivative`, the new function `linearize` takes the derivative of
-an array to one or more arguments, but with the derivative directions
-represented by arguments rather than array axes. This is particularly useful in
-situations where weak forms are made up of symmetric, energy like components,
-combined with terms that require dedicated test fields.
-
-
-NEW: support for searchsorted and interp
-
-Numpy's ufunc support has been extended to include numpy.searchsorted and
-numpy.interp. Both support only a single evaluable argument: searchsorted's
-argument `v` (values to be inserted) and interp's argument `xp` (data point
-coordinates to interpate to). The remaining arguments must be static arrays.
-
-
-NEW: option to disable Newton's line search
-
-The `linesearch` argument of `solver.newton` can now receive the `None` value
-to indicate that line search is to be disabled. Additionally, the legacy
-arguments `searchrange` and `rebound` have been deprecated, and should be
-replaced by `linesearch=solver.NormBased(minscale=searchrange[0],
-acceptscale=searchrange[1], maxscale=rebound)`.
-
-
-IMPROVED: more efficient trimming
-
-The trim routine (which is used for the Finite Cell Method) is rewritten for
-speed and to produce more efficient quadrature schemes. The changes relate to
-the subdivision at the deepest refinement level. While this step used to
-introduce auxiliary vertices at every dimension (lines, faces, volumes), the
-new implementation limits the introduction of vertices to the line segments
-only, resulting in a subdivision that consists of fewer simplices and
-consequently fewer quadrature points.
-
-
-REMOVED: Nutils configuration file
-
-Support for the Nutils configuration file (which used to be located in either
-~/.nutilsrc or ~/.config/nutils/config) has been removed. Instead, the
-following environment variables can be set to override the default Nutils
-settings:
-
-  - NUTILS_PDB  = yes|no
-  - NUTILS_GRACEFULEXIT = yes|no
-  - NUTILS_OUTROOTDIR = path/to/html/logs
-  - NUTILS_OUTROOTURI = uri/to/html/logs
-  - NUTILS_SCRIPTNAME = myapp
-  - NUTILS_OUTDIR = path/to/this/html/log
-  - NUTILS_OUTURI = uti/to/this/html/log
-  - NUTILS_RICHOUTPUT = yes|no
-  - NUTILS_VERBOSE = 1|2|3|4
-  - NUTILS_MATRIX = numpy|scipy|mkl|auto
-  - NUTILS_NPROCS = 1|2|...
-  - NUTILS_CACHE = yes|no
-  - NUTILS_CACHEDIR = path/to/cache
-
-
-DEPRECATED: function methods that have Numpy equivalents
-
-The `nutils.function` methods that have direct equivalents in the `numpy`
-module (`function.sum`, `function.sqrt`, `function.sin`, etc) have been
-deprecated in favour of using Numpy's methods (`numpy.sum`, `numpy.sqrt`,
-`numpy.sin`, etc) and will be removed in the next release. Ultimately, only
-methods that relate to the variable nature of function arrays and therefore
-have no Numpy equivalent, such as `function.grad` and `function.normal`, will
-remain in the function module.
-
-Be aware that some functions were not 100% equivalent to their Numpy
-counterpart. For instance, `function.max` is the equivalent to `numpy.maximum`,
-as the deprecation message helpfully points out. More problematically,
-`function.dot` behaves very differently from both `numpy.dot` and
-`numpy.matmul`. Porting the code over to equivalent instructions will therefore
-require some attention.
-
-
-DEPRECATED: Array.dot for ndim != 1
-
-The `nutils.function.Array.dot` method is incompatible with Numpy's equivalent
-method for arrays of ndim != 1, or when axes are specified (which Numpy does
-not allow). Aiming for 100% compatibility, the next release cycle will remove
-the axis argument and temporarily forbid arguments of ndim != 1. The release
-cycle thereafter will re-enable arguments with ndim != 1, with logic equal to
-Numpy's method. In the meantime, the advice is to rely on `numpy.dot`,
-`numpy.matmul` or the `@` operator instead.
-
-
-DEPRECATED: Array.sum for ndim > 1 without axis argument
-
-The `nutils.function.Array.sum` method by default operates on the last axis.
-This is different from Numpy's behavour, which by default sums all axes. Aiming
-for 100% compatibility, the next release cycle will make the axis argument
-mandatory for any array of ndim > 1. The release cycle thereafter will
-reintroduce the default value to match Numpy's. To prepare for this, relying on
-the current default now triggers a deprecation warning.
-
-
-NEW: iteration count via info.niter
-
-The info struct returned by `solve_withinfo` newly contains the amount of
-iterations as the `niter` attribute:
-
->>> res, info = solver.newton('u:v', res).solve_withinfo(1e-10, maxiter=10)
->>> assert info.niter <= 10
-
-
-NEW: test fields and residual functionals
-
-The `nutils.solver` methods have been generalized to accept scalar valued
-functionals, from which residual vectors are derived through differentiation.
-To this end, a trial/test function pair can be specified as a solve target
-separated by a colon, as in the following example:
-
->>> ns.add_field(('u', 'v'), topo.basis('std', degree=1))
->>> res = topo.integral('∇_i(u) ∇_i(v) dV' @ ns, degree=2)
->>> args = solver.newton('u:v', res).solve(1e-10)
-
-Multiple fields can either comma-joined or provided as a tuple. Note that the
-colon automatically triggers a new-style dictionary return value, even in
-absence of a trialing comma as in the above example.
-
-
-NEW: Namespace.add_field
-
-The namespace from the `nutils.expression_v2` module newly provides the
-`nutils.expression_v2.Namespace.add_field` method, as a convenient shorthand
-for creating fields with the same name as their arguments. That is:
-
->>> ns.add_field(('u', 'v'), topo.basis('std', degree=1), shape=(2,))
-
-is equivalent to
-
->>> basis = topo.basis('std', degree=1)
->>> ns.u = function.dotarg('u', basis, shape=(2,))
->>> ns.v = function.dotarg('v', basis, shape=(2,))
-
-
-NEW: shorthand notation for multiple solver targets
-
-Multiple solver targets can now be specified as a comma-separated string, as a
-shorthand for the string tuple that will remain a valid argument. This means
-the following two invocations are equivalent:
-
->>> args = solver.newton(('u', 'p'), (ures, pres)).solve(1e-10)
->>> args = solver.newton('u,p', (ures, pres)).solve(1e-10)
-
-To distinguish single-length tuples from the single argument legacy notation,
-the former requires a trailing comma. I.e., the following are NOT equivalent:
-
->>> args = solver.newton('u,', (ures,)).solve(1e-10)
->>> u = solver.newton('u', ures).solve(1e-10)

nutils/__init__.py

@@ -7,7 +7,7 @@
 assert sys.version_info >= (3, 5)
 assert LooseVersion(numpy.version.version) >= LooseVersion('1.16'), 'nutils requires numpy 1.16 or higher, got {}'.format(numpy.version.version)
 
-__version__ = version = '8.0'
+__version__ = version = '9a0'
 version_name = 'idiyappam'
 long_version = ('{} "{}"' if version_name else '{}').format(version, version_name)