.. _indra-merge-data:
.. _merge_data_procedure:
.. _merge_data_panel:

.. index::
    Indra; Merge USAXS/SAXS/WAXS data

Merge USAXS/SAXS/WAXS data
===========================

After reducing USAXS/SAXS/WAXS data, the results are stored in Igor folders
organized by sample name: USAXS data in ``root:USAXS:Samplename`` and SAXS
data in ``root:SAXS:Samplename_u`` (or ``Samplename_270_30``). To browse the
current Igor experiment, use the Data Browser (Ctrl-B or Cmd-B).

.. Figure:: media/DataMerge1.jpg
   :align: center
   :width: 380px

To combine USAXS and SAXS data into a single merged dataset, use the Irena
tool :ref:`Merge two datasets <data_merge>`.

.. index::
    Indra; USAXS-SAXS data merge

Data Merging panel
------------------

If needed, load Irena by selecting "*Load Irena SAS macros*" from the Macros
menu. Then select "*Data Manipulation*" from the SAS menu, followed by
"*Merge two data sets*".

.. Figure:: media/DataMerge2.jpg
   :align: left
   :width: 500px
   :figwidth: 820px

This opens a large panel:

.. Figure:: media/DataMerge3.jpg
   :align: left
   :width: 800px
   :figwidth: 820px

To merge desmeared USAXS data with SAXS data, configure as shown above: select
the USAXS checkbox and the DSM checkbox, and set the pull-down menu to
``root:USAXS``. For the second dataset, select the QRS checkbox and set the
pull-down menu to ``root:SAXS``. When DSM data are selected for Dataset 1,
the code automatically inserts ``_270`` in the Dataset 2 match field.

To merge slit-smeared data instead, configure as follows:

.. Figure:: media/DataMerge4.jpg
   :align: left
   :width: 400px
   :figwidth: 820px

When the "*SMR colim?*" checkbox is selected for slit-smeared data, the code
automatically inserts ``_u`` in the Dataset 2 match field.

Testing merge settings
~~~~~~~~~~~~~~~~~~~~~~

Ensure "*Test mode*" is enabled at the top of the right graph before adjusting
merge parameters.

.. Figure:: media/DataMerge5.jpg
   :align: left
   :width: 600px
   :figwidth: 820px

Double-click a dataset in the left column to add it to the graph in red.
Double-click the corresponding SAXS dataset in the right column to add it in
black, plotted against the right axis.

.. Figure:: media/DataMerge6.jpg
   :align: left
   :width: 800px
   :figwidth: 820px

Select the merge method using the "*Merge method*" control at the top of the
window. "*Optimize Overlap*" is the recommended method when both USAXS and SAXS
data have sufficient scatter in the overlap region. For other situations, see
:ref:`Merge two datasets <data_merge>` for descriptions of advanced methods or
consult beamline staff.

Use the round cursor (on the black dataset) and the square cursor (on the red
dataset) to define the overlap region. Data at Q values below the round cursor
are truncated from the black dataset; data above the square cursor are
truncated from the red dataset. Sufficient overlap between the two datasets is
required.

Select the parameters to optimize: typically "*Data 1 background*" and
"*Data 2 scaling*" (top-left checkboxes) are always needed. "*Data 2 Q shift*"
may be needed in some cases.

Click "*Process data*" to preview the merge. A blue curve shows the merged
result. Adjust cursor positions as needed until the overlap looks correct.

.. Figure:: media/DataMerge7.jpg
   :align: left
   :width: 800px
   :figwidth: 820px

Saving merged data
~~~~~~~~~~~~~~~~~~

After a satisfactory merge, you have several options:

* Click "*Save data*" (shown in orange until saved) to save the current merged
  dataset.

* Enable "*Merge mode*" and use "*Process data*" interactively — double-click
  a pair of datasets from the left and right columns, and the code processes
  and optionally saves them automatically.

* For batch merging, select ranges of files in each column and use "*Process
  and save data*". The code pairs the first file from the left column with the
  first from the right column, the second with the second, and so on.
  Selections in the two columns do not need to occupy the same rows. See
  :ref:`Data Merge tool <data_merge>` in the Irena manual for full details.

.. Figure:: media/DataMerge8.jpg
   :align: left
   :width: 800px
   :figwidth: 820px