Merged in feature/RAM-3656_field_analysis_v2 (pull request #390)

Feature/RAM-3656 field analysis v2

Approved-by: Randy Taylor

docs/source/changelog.rst

@@ -30,6 +30,30 @@ Core
   and out-of-place multiplication. E.g. ``Point(1, 2) * 2`` will return a new point at (2, 4) and
   also change the original point to (2, 4).
 
+Field Analysis
+^^^^^^^^^^^^^^
+
+* There is a new module for performing field analysis that leverages the 1D metrics framework. This
+  is an alternative and successor to the original field analysis module. You can read more here: :ref:`field-profile-analysis`.
+
+Profiles & 1D Metrics
+^^^^^^^^^^^^^^^^^^^^^
+
+* 1D Profile Metrics have two new methods: ``geometric_center_idx`` and ``cax_index`` that return the index
+  (interpolated) for their respective values.
+* The ``plot`` method for profiles now includes a ``mirror`` parameter. This will mirror the profile about the
+  geomtric center or beam center index. This is useful for visualizing the symmetry of the profile.
+* Physical profile plots now also plot the x-axis in physical values on a secondary axis.
+* 1D metrics now have a ``full_name`` property that concatenates the name of the metric and the unit if applicable.
+* Calculated metrics of a profile that are stored in the ``metric_values`` attribute are now saved using the full name
+  as described above. This means if you access metrics this way, you may need to update the lookup to include the unit.
+* Two new metrics have been added: ``CAXtoLeftBeamEdge`` and ``CAXToRightBeamEdge``. These metrics will calculate the distance
+  from the CAX to the left and right beam edges, respectively.
+* The ``FlatnessDifferenceMetric`` had a bug that would cause plotting to fail.
+* The ``SymmetryPointDifferenceQuotientMetric`` 's default max and min range has been adjusted to 100-105 to better reflect default values.
+* The ``PenumbraLeftMetric`` and ``PenumbraRightMetric`` had their unit's changed from % to mm. % was incorrect.
+* The ``SlopeMetric`` would sometimes fail to plot if an uneven number of points were calculated over.
+
 v 3.23.0
 --------
 

docs/source/field_analysis.rst

@@ -4,6 +4,11 @@
 Field Analysis
 ==============
 
+.. warning::
+
+    This module will be deprecated in favor of the newer method of :ref:`field-profile-analysis` at some point in the future.
+    This module will either be moved to a ``deprecated`` module in v4 or simply removed.
+
 Overview
 --------
 

docs/source/field_profile_analysis.rst

@@ -0,0 +1,339 @@
+.. _field-profile-analysis:
+
+======================
+Field Profile Analysis
+======================
+
+The modular field analysis is the newer implementation of the :ref:`field_analysis_module` concept.
+Colloquially, it is referred to as "v2" of the field analysis module.
+It leverages the new :ref:`profiles` framework to provide a more flexible way
+to analyze fields.
+
+.. note::
+
+    If you are familiar with the old field analysis module and want to convert, you can read about the differences in
+    :ref:`comparison-to-field-analysis-v1`.
+
+Overview
+========
+
+The field profile analysis module (``pylinac.field_profile_analysis``) allows a physicist to analyze various metrics of an open radiation
+field from extracted profiles. The user can specify the location and width of the profiles
+from the image. They can also select various metrics to compute on the profiles as well
+as write custom plugins to compute additional metrics as necessary for the specific application
+of interest. The use cases and assumptions/constraints are the same as for the :ref:`profiles <profiles>` framework.
+
+Typical Usage
+=============
+
+To analyze profiles from an open field, the user should import the class, pass the path to the open beam, and then analyze the profiles from the beam.
+
+.. code-block:: python
+
+  from pylinac import FieldProfileAnalysis, Centering, Normalization, Edge
+  from pylinac.metrics.profile import (
+      PenumbraLeftMetric,
+      PenumbraRightMetric,
+      SymmetryAreaMetric,
+      FlatnessDifferenceMetric,
+  )
+
+  path = r"C:\path\to\open_field.dcm"
+  field_analyzer = FieldProfileAnalysis(path)
+  field_analyzer.analyze(
+      centering=Centering.BEAM_CENTER,
+      x_width=0.02,
+      y_width=0.02,
+      normalization=Normalization.BEAM_CENTER,
+      edge_type=Edge.INFLECTION_DERIVATIVE,
+      ground=True,
+      metrics=(
+          PenumbraLeftMetric(),
+          PenumbraRightMetric(),
+          SymmetryAreaMetric(),
+          FlatnessDifferenceMetric(),
+      ),
+  )
+  field_analyzer.plot_analyzed_images(show_grid=True, mirror="beam")
+
+which will output 3 images: the image itself marked with where the profiles were taken
+and the X and Y profile plots along with the metrics plotted.
+
+.. plot::
+  :include-source: false
+
+  from pylinac import FieldProfileAnalysis, Centering, Normalization
+  from pylinac.metrics.profile import PenumbraLeftMetric, PenumbraRightMetric, SymmetryAreaMetric, FlatnessDifferenceMetric
+
+  field_analyzer = FieldProfileAnalysis.from_demo_image()
+  field_analyzer.analyze(centering=Centering.BEAM_CENTER, x_width=0.02, y_width=0.02, normalization=Normalization.BEAM_CENTER, ground=True, metrics=(PenumbraLeftMetric(), PenumbraRightMetric(), SymmetryAreaMetric(), FlatnessDifferenceMetric()))
+  field_analyzer.plot_analyzed_images(mirror='beam')
+
+Analysis Options
+================
+
+Centering
+^^^^^^^^^
+
+There are 3 centering options: manual, beam center, and geometric center.
+
+Manual
+######
+
+Manual centering means that you as the user specify the position of the image that the profiles are taken from.
+
+.. code-block:: python
+
+    from pylinac import FieldProfileAnalysis, Centering
+
+    fa = FieldProfileAnalysis(...)
+    fa.analyze(..., centering=Centering.MANUAL)  # default is the middle of the image.
+
+    # or specify a custom location
+    fa.analyze(..., centering=Centering.MANUAL, position=(0.3, 0.8))
+    # take profile at 30% height and 80% width
+
+Beam center
+###########
+
+This is the default centering option. It first looks for the field to find the approximate center along each axis.
+Then it extracts the profiles at these coordinates. This is helpful if you always want to be near the center of the field, even for offset fields or wedges.
+
+.. code-block:: python
+
+    from pylinac import FieldProfileAnalysis, Centering
+
+    fa = FieldProfileAnalysis(...)
+    fa.analyze(...)  # nothing special needed as it's the default
+
+    # Specifying a position here will be ignored
+    fa.analyze(..., centering=Centering.BEAM_CENTER, position=(0.1, 0.4))
+    # this is allowed but will result in the same result as above
+
+Geometric center
+################
+
+The geometric center will always find the middle pixel and extract the profiles from there.
+This is helpful if you always want to be at the center of the image.
+
+.. code-block:: python
+
+    from pylinac import FieldProfileAnalysis, Centering
+
+    fa = FieldProfileAnalysis(...)
+    fa.analyze(..., centering=Centering.GEOMETRIC_CENTER)
+
+.. _edge-type:
+
+Edge detection
+^^^^^^^^^^^^^^
+
+Edge detection is important for determining the field width and beam center (which is often used for symmetry).
+There are 3 detection strategies: FWHM, inflection via derivative, and inflection via the Hill/sigmoid/4PNLR function.
+
+FWHM
+####
+
+The full-width half-max strategy is traditional and works for flat beams. It can give poor values for FFF beams.
+
+.. code-block:: python
+
+    from pylinac import FieldProfileAnalysis, Edge
+
+    fa = FieldProfileAnalysis(...)
+    fa.analyze(..., edge_type=Edge.FWHM)
+
+
+Inflection (derivative)
+#######################
+
+The inflection point via the derivative is useful for both flat and FFF beams, and is thus the default for ``FieldProfileAnalysis``.
+The method will find the positions of the max and min derivative of the values. Using a 0-crossing of the 2nd derivative
+can be tripped up by noise so it is not used.
+
+.. note::
+
+    This method is recommended for high spatial resolution images such as the EPID, where the derivative has several points to use at the beam edge.
+    It is not recommended for 2D device arrays.
+
+.. code-block:: python
+
+    from pylinac import FieldProfileAnalysis, Edge
+
+    fa = FieldProfileAnalysis(...)  # nothing special needed as it's the default
+
+    # you may also specify the edge smoothing value. This is a gaussian filter applied to the derivative just for the purposes of finding the min/max derivative.
+    # This is to ensure the derivative is not caught by some noise. It is usually not necessary to change this.
+    fa = FieldProfileAnalysis(..., edge_smoothing_ratio=0.005)
+
+
+Inflection (Hill)
+#################
+
+The inflection point via the Hill function is useful for both flat and FFF beams
+The fitting of the function is best for low-resolution data.
+The Hill function, the sigmoid function, and 4-point non-linear regression belong to a family of logistic equations to fit a dual-curved value.
+Since these fit a function to the data the resolution problems are eliminated. Some examples can be
+seen `here <https://en.wikipedia.org/wiki/Sigmoid_function#Examples>`__. The generalized logistic function has helpful visuals as well
+`here <https://en.wikipedia.org/wiki/Generalised_logistic_function>`__.
+
+The function used here is:
+
+:math:`f(x) = A + \frac{B - A}{1 + \frac{C}{x}^D}`
+
+where :math:`A` is the low asymptote value (~0 on the left edge of a field),
+:math:`B` is the high asymptote value (~1 for a normalized beam on the left edge),
+:math:`C` is the inflection point of the sigmoid curve,
+and :math:`D` is the slope of the sigmoid.
+
+The function is fitted to the edge data of the field on each side to return the function. From there, the inflection point, penumbra, and slope can be found.
+
+.. note::
+
+    This method is recommended for low spatial resolution images such as 2D device arrays, where there is very little data at the beam edges.
+    While it can be used for EPID images as well, the fit can have small errors as compared to the direct data.
+    The fit, however, is much better than a linear or even spline interpolation at low resolutions.
+
+.. code-block:: python
+
+    from pylinac import FieldProfileAnalysis, Edge
+
+    fa = FieldProfileAnalysis(..., edge_type=Edge.INFLECTION_HILL)
+
+    # you may also specify the Hill window. This is the size of the window (as a ratio) to use to fit the field edge to the Hill function.
+    fa = FieldProfileAnalysis(..., edge_type=Edge.INFLECTION_HILL, hill_window_ratio=0.05)
+    # i.e. use a 5% field width about the edges to fit the Hill function.
+
+
+.. note::
+
+    When using this method, the fitted Hill function will also be plotted on the image. Further, the exact field edge
+    marker (green x) may not align with the Hill function fit. This is just a rounding issue due to the plotting mechanism.
+    The field edge is really using the Hill fit under the hood.
+
+Normalization
+-------------
+
+There are 4 options for interpolation: ``NONE``, ``GEOMETRIC_CENTER``, ``BEAM_CENTER``, and ``MAX``. These should be
+self-explanatory, especially in light of the centering explanations.
+
+.. code-block:: python
+
+    from pylinac import FieldProfileAnalysis, Normalization
+
+    fa = FieldProfileAnalysis(...)
+    fa.analyze(..., normalization_method=Normalization.BEAM_CENTER)
+
+
+.. _choosing-field-metrics:
+
+Choosing Metrics
+================
+
+The metrics the user can use in the field/profile analysis that come out of the box
+can be viewed in this list: :ref:`profile_builtin_plugins`. These metrics can then
+be passed to the ``metrics`` parameter. The user can mix and match as desired.
+It's also possible to write custom plugins; see :ref:`using-custom-field-analysis-plugins`.
+
+.. code-block:: python
+
+    from pylinac import FieldProfileAnalysis
+    from pylinac.metrics.profile import PenumbraRightMetric, SlopeMetric, SymmetryAreaMetric
+
+    p = Path(r"C:\path\to\open_field.dcm")
+    field_analyzer = FieldProfileAnalysis(p)
+    field_analyzer.analyze(
+        metrics=[PenumbraRightMetric(), SlopeMetric(), SymmetryAreaMetric()]
+    )
+    field_analyzer.plot_analyzed_images()
+
+Customizing Metrics
+===================
+
+To change the name or parameters of a metric, pass the relevant parameters to the metric's constructor.
+E.g. to use 90/10 for the penumbra distance instead of 80/20:
+
+.. code-block:: python
+
+  from pylinac import FieldProfileAnalysis
+  from pylinac.metrics.profile import PenumbraRightMetric
+
+  fa = FieldProfileAnalysis(...)
+  fa.analyze(metrics=[PenumbraRightMetric(lower=10, upper=90, color="r", ls="--")])
+  # will use 90/10 instead of 80/20 and plot the line in red and dashed
+  fa.plot_analyzed_images()
+
+Each metric has its own parameters that can be customized. See the metric's documentation for more information.
+
+Accessing results
+=================
+
+Results from the analysis can be printed as a simple string using :meth:`~pylinac.field_profile_analysis.FieldProfileAnalysis.results`.
+The ideal method is to access the results using the :meth:`~pylinac.field_profile_analysis.FieldProfileAnalysis.results_data` method, which
+can return a JSON string, a dictionary, or a :class:`~pylinac.field_profile_analysis.FieldResult` that can be used to access the results.
+
+See also :ref:`exporting-results`.
+
+.. _using-custom-field-analysis-plugins:
+
+Using Custom Plugins
+====================
+
+To analyze custom metrics on the profiles, the user can write custom plugins.
+First, :ref:`create the plugin itself <writing-profile-plugins>`. Then,
+pass it to the ``metrics`` parameter per :ref:`choosing-field-metrics`.
+
+.. code-block:: python
+
+    from pylinac import FieldProfileAnalysis
+    from pylinac.metrics.profile import PenumbraLeftMetric
+    from my_custom_plugins import MyCustomMetric
+
+    p = Path(r"C:\path\to\open_field.dcm")
+    field_analyzer = FieldProfileAnalysis(p)
+    field_analyzer.analyze(metrics=[MyCustomMetric(), PenumbraLeftMetric()])
+    field_analyzer.plot_analyzed_images()
+
+.. _comparison-to-field-analysis-v1:
+
+Comparison to field analysis v1
+===============================
+
+In comparison to the original :ref:`field_analysis_module` module,
+this updated module:
+
+* Almost every metric will result in the same value. E.g. flatness, symmetry, etc. The only
+  times that metrics showed differences was if interpolation was "None". In such a case,
+  the v1 penumbra may be slightly larger. This is due to the field edge index "snapping" to the nearest pixel.
+  In v2, the edge is always interpolated and never snaps.
+* Is much easier and more logical to write new plugins for. The plugins are modular and are not tightly coupled
+  to this module.
+* Is loosely coupled to the metrics themselves. Since the metrics themselves are
+  self-contained, can be customized directly, and don't rely on any specific data massaging or formatting, they can be used in other modules.
+* Does not do any device-specific analysis (e.g. IC Profiler). The original module and intent
+  was to have a generic device-to-profile framework. This ended up being a considerable amount
+  of work and ultimately we felt it fell out of the scope of pylinac, which is to focus on image
+  analysis. If you desire device-specific profile analysis, the conversion from the original file/format
+  a 1D array of values is your responsibility.
+* There is no explicit interpolation method. Values are always interpolated linearly under the hood.
+* v1 uses language like "top, left, bottom, right". In v2 everything is left and right, including the
+  y-profile (vertical). Rotating the y-profile 90 degrees counterclockwise will
+  give the same understanding of language. I.e. the "top" is the y-left value.
+
+  .. image:: images/field_analysis_v2.png
+      :width: 750
+      :align: center
+
+* While not strictly a user benefit, the modularity of the metrics and the analysis itself
+  makes the codebase much cleaner and easier to maintain (v1 is ~1500 LOC vs v2 at ~400).
+
+
+API Documentation
+=================
+
+
+.. autoclass:: pylinac.field_profile_analysis.FieldProfileAnalysis
+    :members:
+    :inherited-members:
+
+.. autoclass:: pylinac.field_profile_analysis.FieldProfileResult

docs/source/index.rst

@@ -29,6 +29,7 @@
    winston_lutz
    winston_lutz_multi
    planar_imaging
+   field_profile_analysis
    field_analysis
    nuclear