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+utils/get_grid.m

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+% get_grid returns coordinate system for input shape ish and pixel size px
+% 
+% Example:
+%   [g1,g2] = get_grid(512, 29e-9);  
+%   returns an fft-shifted coordinate system of size 512x512 with a pixel size of 29 nm
+
+%*-----------------------------------------------------------------------*
+%|                                                                       |
+%|  Except where otherwise noted, this work is licensed under a          |
+%|  Creative Commons Attribution-NonCommercial-ShareAlike 4.0            |
+%|  International (CC BY-NC-SA 4.0) license.                             |
+%|                                                                       |
+%|  Copyright (c) 2017 by Paul Scherrer Institute (http://www.psi.ch)    |
+%|                                                                       |
+%|       Author: CXS group, PSI                                          |
+%*-----------------------------------------------------------------------*
+% You may use this code with the following provisions:
+%
+% If the code is fully or partially redistributed, or rewritten in another
+%   computing language this notice should be included in the redistribution.
+%
+% If this code, or subfunctions or parts of it, is used for research in a 
+%   publication or if it is fully or partially rewritten for another 
+%   computing language the authors and institution should be acknowledged 
+%   in written form in the publication: “Data processing was carried out 
+%   using the “cSAXS matlab package” developed by the CXS group,
+%   Paul Scherrer Institut, Switzerland.” 
+%   Variations on the latter text can be incorporated upon discussion with 
+%   the CXS group if needed to more specifically reflect the use of the package 
+%   for the published work.
+%
+% A publication that focuses on describing features, or parameters, that
+%    are already existing in the code should be first discussed with the
+%    authors.
+%   
+% This code and subroutines are part of a continuous development, they 
+%    are provided “as they are” without guarantees or liability on part
+%    of PSI or the authors. It is the user responsibility to ensure its 
+%    proper use and the correctness of the results.
+
+function [gx,gy] = get_grid(ish, px)
+
+    if length(ish) == 1 
+        sh = [ish ish];
+    elseif length(ish) == 2
+        sh = ish;
+    else
+        error('Input shape has to be 1D or 2D')
+    end
+    
+    if length(px) == 1 
+        dx = [px px];
+    elseif length(ish) ==2
+        dx = px;
+    else
+        error('Pixel size has to be 1D or 2D')
+    end
+    
+    x = fftshift(-sh(2)/2:floor((sh(2)-1)/2))*dx(2);
+    y = fftshift(-sh(1)/2:floor((sh(1)-1)/2))*dx(1);
+    
+    [gx,gy] = meshgrid(x,y);
+    
+end