Add Tabular Model.

add another test and fix comparison

Add a changelog entry [skip ci]

fix a changelog entry [skip ci]

CHANGES.rst

@@ -1,7 +1,12 @@
+1.1.1(Unreleased)
+-----------------
+
+- Added Tabular model. [#214]
+
 1.0.5 (2016-06-28)
 ------------------
 
-- Fixed a memory leak when reading wcs that grew memory to over 10 Gb
+- Fixed a memory leak when reading wcs that grew memory to over 10 Gb. [#200]
 
 1.0.4 (2016-05-25)
 ------------------

asdf/tags/transform/__init__.py

@@ -7,3 +7,4 @@
 from .compound import *
 from .projections import *
 from .polynomial import *
+from .tabular import *

asdf/tags/transform/tabular.py

@@ -0,0 +1,69 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
+# -*- coding: utf-8 -*-
+
+from __future__ import absolute_import, division, unicode_literals, print_function
+
+import numpy as np
+from numpy.testing import assert_array_equal
+from ... import yamlutil
+
+from .basic import TransformType
+
+__all__ = ['TabularType']
+
+
+class TabularType(TransformType):
+    import astropy
+    name = "transform/tabular"
+    types = [astropy.modeling.models.Tabular2D,
+             astropy.modeling.models.Tabular1D
+             ]
+
+    @classmethod
+    def from_tree_transform(cls, node, ctx):
+        from astropy import modeling
+        lookup_table = node.pop("lookup_table")
+        dim = lookup_table.ndim
+        name = node.get('name', None)
+        fill_value = node.pop("fill_value", None)
+        points = np.asarray(node['points'])
+        if dim == 1:
+            model = modeling.models.Tabular1D(points=points, lookup_table=lookup_table,
+                                              method=node['method'], bounds_error=node['bounds_error'],
+                                              fill_value=fill_value, name=name)
+        elif dim == 2:
+            model = modeling.models.Tabular2D(points=points, lookup_table=lookup_table,
+                                              method=node['method'], bounds_error=node['bounds_error'],
+                                              fill_value=fill_value, name=name)
+        else:
+            tabular_class = modeling.models.tabular_model(dim, name)
+
+            model = tabular_class(points=points, lookup_table=lookup_table,
+                                  method=node['method'], bounds_error=node['bounds_error'],
+                                  fill_value=fill_value, name=name)
+
+        return model
+
+    @classmethod
+    def to_tree_transform(cls, model, ctx):
+        node = {}
+        node["fill_value"] = model.fill_value
+        node["lookup_table"] = model.lookup_table
+        node["points"] = model.points
+        node["method"] = str(model.method)
+        node["bounds_error"] = model.bounds_error
+        node["name"] = model.name
+        return yamlutil.custom_tree_to_tagged_tree(node, ctx)
+
+    @classmethod
+    def assert_equal(cls, a, b):
+        assert_array_equal(a.lookup_table, b.lookup_table)
+        assert_array_equal(a.points, b.points)
+        assert (a.method == b.method)
+        if a.fill_value is None:
+            assert b.fill_value is None
+        elif np.isnan(a.fill_value):
+            assert np.isnan(b.fill_value)
+        else:
+            assert(a.fill_value == b.fill_value)
+        assert(a.bounds_error == b.bounds_error)

asdf/tags/transform/tests/test_transform.py

@@ -3,6 +3,8 @@
 
 from __future__ import absolute_import, division, unicode_literals, print_function
 
+import numpy as np
+
 try:
     import astropy
 except ImportError:
@@ -126,3 +128,20 @@ def test_generic_projections(tmpdir):
         }
 
         helpers.assert_roundtrip_tree(tree, tmpdir)
+
+
+@pytest.mark.skipif('not HAS_ASTROPY')
+def test_tabular_model(tmpdir):
+    points = np.arange(0, 5)
+    values = [1., 10, 2, 45, -3]
+    model = astmodels.Tabular1D(points=points, lookup_table=values)
+    tree = {'model': model}
+    helpers.assert_roundtrip_tree(tree, tmpdir)
+    table = np.array([[ 3.,  0.,  0.],
+                      [ 0.,  2.,  0.],
+                      [ 0.,  0.,  0.]])
+    points = ([1, 2, 3], [1, 2, 3])
+    model2 = astmodels.Tabular2D(points, lookup_table=table, bounds_error=False,
+                                 fill_value=None, method='nearest')
+    tree = {'model': model2}
+    helpers.assert_roundtrip_tree(tree, tmpdir)