Add change to release notes and docs for polaris

This commit makes changes to the release notes and polaris docs for the new fourier filter tool and the fixed bug for being able to use a list.

re: #2773

docs/source/release/v4.3.0/diffraction.rst

@@ -23,6 +23,7 @@ Powder Diffraction
 - The create_total_scattering_pdf merging banks no longer matches spectra with scale, it now only matches with offset.
 - The Polaris create_total_scattering_pdf can now be given an parameter `output_binning` that will be used to rebin the output_pdf.
 - The polaris create_total_scattering_pdf function can now accept a `pdf_type` argument to set the pdf_output type.
+- The polaris create_total_scattering_pdf function can now accept a `freq_params` argument to perfomr a fourier filter on the run.
 - :ref:`HRPDSlabCanAbsorption <algm-HRPDSlabCanAbsorption-v1>` now accepts any thickness parameter and not those in a specified list.
 
 Engineering Diffraction
@@ -50,6 +51,7 @@ Powder Diffraction
 - A bug has been fixed that prevented unicode strings being given as a lim file directory in polaris create_total_scattering_pdf merging banks.
 - A bug has been fixed that caused Polaris.focus to fail with `do_absorption_Corrections=True`.
 - A bug has been fixed that caused empty runs to be subtracted twice when specifying `sample_empty` in `Polaris.focus`.
+- A bug has been fixed that prevented lists being given for `q_lims` in polaris create_total_scattering_pdf while merging banks.
 
 Engineering Diffraction
 -----------------------

docs/source/techniques/ISISPowder-Polaris-v1.rst

@@ -167,16 +167,6 @@ create_total_scattering_pdf
 The *create_total_scattering_pdf* method allows a user to create a Pair Distribution Function (PDF)
 from focused POLARIS data, with a view performing further total scattering analysis.
 
-With no merging criteria specified, *merge_banks=False* a PDF will be generated for each bank within
-the focused_workspace. The type of PDF output can be set with the keyword argument `pdf_type`, with the
-option of `G(r)`, `g(r)`, `RDF(r)` (defaults to `G(r)`). If run with *merge_banks=True* a PDF will be
-generated based on the weighted sum of the detector banks performed using supplied Q limits
-*q_lims=q_limits*, Q_limits can be in the form of a numpy array with shape (2, x) where x is the number
-of detectors, or a string containing the directory of an appropriately formatted `.lim` file.
-
-This function can also be called with the argument `output_binning` which will rebin the output PDF as
-with the rebin algorithm.
-
 This function applies the placzek self scattering correction from
 :ref:CalculatePlaczekSelfScattering <algm-CalculatePlaczekSelfScattering> before calculating the PDF
 
@@ -191,6 +181,19 @@ for example:
 
 Or the focused file must be in the output directory of the POLARIS instrument.
 
+The output PDF can be customized with the following parameters:
+
+- By calling with `pdf_type` the type of PDF output can be specified, with the option of `G(r)`,
+  `g(r)`, `RDF(r)` (defaults to `G(r)`).
+- By calling with `merge_banks=True` a PDF will be generated based on the weighted sum of the detector
+  banks performed using supplied Q limits `q_lims=q_limits`, q_limits can be in the form of an array or
+  with shape (2, x) where x is the number of detectors, or a string containing the directory
+  of an appropriately formatted `.lim` file. By default or specifically called with `merge_banks=False`
+  a PDF will be generated for each bank within the focused_workspace.
+- By calling with `output_binning` which will rebin the output PDF as with the rebin algorithm.
+- By calling with `freq_params` a fourier filter will be performed on the focused signal removing any
+  components from atomic distances outside of the parameters. The parameters must be given as list:
+  [lower], or [lower, upper].
 
 Example
 =======
@@ -198,7 +201,11 @@ Example
 ..  code-block:: python
 
   polaris_example.create_total_scattering_pdf(run_number='12345',
-                                              merge_banks=False)
+                                              merge_banks=True,
+                                              q_lims=[[2.5, 3, 4, 6, 7], [3.5, 5, 7, 11, 40]],
+                                              output_binning=[0,0.1,20],
+                                              pdf_type='G(r)',
+                                              freq_params=[1])
 
 .. _calibration_mapping_polaris-isis-powder-ref: