diff --git a/documentation/user_docs/docs/images/InstrumentView_issues_source.pptx b/documentation/user_docs/docs/images/InstrumentView_issues_source.pptx new file mode 100644 index 0000000000..e2287a74b5 Binary files /dev/null and b/documentation/user_docs/docs/images/InstrumentView_issues_source.pptx differ diff --git a/documentation/user_docs/docs/manual/Data_diagnostics.rst b/documentation/user_docs/docs/manual/Data_diagnostics.rst index 028fb1edd0..ca77661ccc 100644 --- a/documentation/user_docs/docs/manual/Data_diagnostics.rst +++ b/documentation/user_docs/docs/manual/Data_diagnostics.rst @@ -128,7 +128,7 @@ These artefacts will have spherical symmetry around the beam direction. To clear wout = instrument_view_cut(sqw_source,[0,theta_step,theta_max],[En_min,En_step,En_max]); Where *sqw_source* is an source ``sqw`` object with pixels, and two other arguments define binning in two directions. ``theta`` -- the angle between beam and detector directions and ``En`` are the energy transfer values. -The algorithm makes the cut in the spherical coordinate system wich z-axis is aligned along the beam direction. +The algorithm makes the cut in the spherical coordinate system which z-axis is aligned along the beam direction. According to Horace agreement, beam in Horace is directed along :math:`e_{x}` coordinate or direction :math:`\vec{u}` of the crystal (see Chapter on :ref:`Generating SQW files` for details): @@ -210,11 +210,12 @@ To clarify this issue exactly, one may run ``instrument_view_cut`` with ``-check :: - wout = instrument_view_cut(source_sqw,[0,0.2,140],[],'-check_correspondence'); + wout = instrument_view_cut(source_sqw,[0,140],[],'-check_correspondence'); plot(wout) -This option force 2D cut in :math:`|k_{f}|` - :math:`dE` coordinates. As these values are connected by -arithmetic relationship, the cut in these coordinates should represent a line. If one see a 2-dimensional image instead, +This option force 2D cut in :math:`|k_{f}|` - :math:`dE` coordinates. Binning in :math:`\theta` direction is ignored +but integration range in :math:`\theta` direction is respected. As :math:`|k_{f}|` - :math:`dE` are connected by +arithmetic relationship, the cut in these coordinates should become a line. If one see a 2-dimensional image instead, the correspondence between pixel information describing neutron "pseudo-events" and experiment information describing runs and crystal orientation is violated. The following figure represents two ``sqw`` datasets, where the first one was build with correct correspondence between experiment and pixels information and the second one -- where @@ -227,7 +228,7 @@ this correspondence have been broken. Correct -- a) and broken -- b) relationship between experiment information and pixels information. -The dataset with broken pixel-experiment correspondence can be cut, sliced and multifitted, but Tobyfit would not -produce correct result on it. To use Tobyfit, one needs to rebuild such ``sqw`` dataser using Horace-4. If you do not +The dataset with broken pixel-experiment correspondence can be cut, sliced and multi-fitted, but Tobyfit would not +produce correct result on it. To use Tobyfit, one needs to rebuild such ``sqw`` dataset using Horace-4. If you do not have original data to reproduce such ``sqw`` dataset and need to use Tobyfit, contact HoraceHelp@stfc.ac.uk. The team should be able to help you rebuilding such ``sqw`` dataset.