Merge pull request #49 from nden/add-polynomials

add polynomial schemas

schemas/stsci.edu/asdf/0.1.0/transform/polynomial.yaml

@@ -0,0 +1,44 @@
+%YAML 1.1
+---
+$schema: "http://stsci.edu/schemas/yaml-schema/draft-01"
+id: "http://stsci.edu/schemas/asdf/0.1.0/transform/polynomial"
+tag: "tag:stsci.edu:asdf/0.1.0/transform/polynomial"
+title: >
+  A Polynomial model.
+
+description: |
+  A polynomial model represented by its coefficients stored in
+  an ndarray of shape ``(n+1,)`` for univariate polynomials or ``(n+1, n+1)``
+  for polynomials with 2 variables, where ``n`` is the highest total degree
+  of the polynomial.
+
+  :math:`P = \sum_{i, j=0}^{i+j=n}c_{ij} * x^{i} * y^{j}`
+
+  Invertability: This transform is not automatically invertible.
+
+examples:
+  -
+    - :math:`P = 1.2 + 0.3 * x + 56.1 * x^{2}`
+    - |
+        !transform/polynomial
+          coefficients: !core/ndarray
+                          [1.2, 0.3, 56.1]
+  -
+    - :math:`P = 1.2 + 0.3 * x + 3 * x * y + 2.1 * y^{2}`
+    - |
+        !transform/polynomial
+          coefficients: !core/ndarray
+                          [[1.2, 0.0, 2.1],
+                           [0.3, 3.0, 0.0],
+                           [0.0, 0.0, 0.0]]
+
+type: object
+properties:
+  coefficients:
+    description: |
+      An array with coefficients.
+    anyOf:
+      - $ref: ../core/ndarray
+      - type: array
+required: [coefficients]
+

schemas/stsci.edu/asdf/0.1.0/transform/scale.yaml

@@ -0,0 +1,16 @@
+%YAML 1.1
+---
+$schema: "http://stsci.edu/schemas/yaml-schema/draft-01"
+id: "http://stsci.edu/schemas/asdf/0.1.0/transform/scale"
+tag: "tag:stsci.edu:asdf/0.1.0/transform/scale"
+title: >
+  A Scale model.
+description: >
+  Multiply the input by a factor.
+
+type: object
+properties:
+  factor:
+    type: number
+    description: Multiplication factor.
+requiredProperties: [factor]

schemas/stsci.edu/asdf/0.1.0/transform/shift.yaml

@@ -0,0 +1,16 @@
+%YAML 1.1
+---
+$schema: "http://stsci.edu/schemas/yaml-schema/draft-01"
+id: "http://stsci.edu/schemas/asdf/0.1.0/transform/shift"
+tag: "tag:stsci.edu:asdf/0.1.0/transform/shift"
+title: >
+  A Shift opeartion.
+description: >
+  Apply an offset in one direction.
+
+type: object
+properties:
+  offset:
+    type: number
+    description: Offset in one direction.
+requiredProperties: [offset]

source/conf.py

@@ -27,6 +27,7 @@
 
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
+mathjax_path="https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"
 extensions = ['sphinx.ext.mathjax', 'sphinx.ext.ifconfig', 'sphinxext.category']
 
 # Add any paths that contain templates here, relative to this directory.

source/schemas/transform.rst

@@ -41,6 +41,15 @@ Arithmetic operations
    stsci.edu/asdf/0.1.0/transform/divide.rst
    stsci.edu/asdf/0.1.0/transform/power.rst
 
+Simple Transforms
+-----------------
+
+.. toctree::
+   :maxdepth: 1
+
+   stsci.edu/asdf/0.1.0/transform/shift.rst
+   stsci.edu/asdf/0.1.0/transform/scale.rst
+
 Projections
 -----------
 
@@ -50,3 +59,12 @@ Projections
    stsci.edu/asdf/0.1.0/transform/affine.rst
    stsci.edu/asdf/0.1.0/transform/rotate2d.rst
    stsci.edu/asdf/0.1.0/transform/tangent.rst
+
+Polynomials
+-----------
+
+.. toctree::
+   :maxdepth: 1
+
+   stsci.edu/asdf/0.1.0/transform/polynomial.rst
+