From 9ccaa364f7d837fe357cf121f441aec2ac830b7e Mon Sep 17 00:00:00 2001
From: Shane Maloney <shane.maloney@dias.ie>
Date: Wed, 15 May 2024 11:49:49 +0100
Subject: [PATCH] Fix WCS v array indexing errors

---
 xrayvision/imaging.py            | 20 ++++++++++----------
 xrayvision/tests/test_imaging.py | 16 ++++++++--------
 2 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/xrayvision/imaging.py b/xrayvision/imaging.py
index f4bc908..06afca8 100644
--- a/xrayvision/imaging.py
+++ b/xrayvision/imaging.py
@@ -236,15 +236,15 @@ def generate_header(vis: Visibility, *,
     -------
     :
     """
-    header = {'crval1': (vis.offset[0]).to_value(apu.arcsec),
-              'crval2': (vis.offset[1]).to_value(apu.arcsec),
-              'cdelt1': (pixel_size[0]*apu.pix).to_value(apu.arcsec),
-              'cdelt2': (pixel_size[1]*apu.pix).to_value(apu.arcsec),
+    header = {'crval1': (vis.offset[1]).to_value(apu.arcsec),
+              'crval2': (vis.offset[0]).to_value(apu.arcsec),
+              'cdelt1': (pixel_size[1]*apu.pix).to_value(apu.arcsec),
+              'cdelt2': (pixel_size[0]*apu.pix).to_value(apu.arcsec),
               'ctype1': 'HPLN-TAN',
               'ctype2': 'HPLT-TAN',
               'naxis': 2,
-              'naxis1': shape[0].value,
-              'naxis2': shape[1].value,
+              'naxis1': shape[1].value,
+              'naxis2': shape[0].value,
               'cunit1': 'arcsec',
               'cunit2': 'arcsec'}
     return header
@@ -310,15 +310,15 @@ def map_to_vis(amap: GenericMap, *, u: Quantity[1/apu.arcsec], v: Quantity[1/apu
     meta = amap.meta
     new_pos = np.array([0., 0.])
     if "crval1" in meta:
-        new_pos[0] = float(meta["crval1"])
+        new_pos[1] = float(meta["crval1"])
     if "crval2" in meta:
-        new_pos[1] = float(meta["crval2"])
+        new_pos[0] = float(meta["crval2"])
 
     new_psize = np.array([1., 1.])
     if "cdelt1" in meta:
-        new_psize[0] = float(meta["cdelt1"])
+        new_psize[1] = float(meta["cdelt1"])
     if "cdelt2" in meta:
-        new_psize[1] = float(meta["cdelt2"])
+        new_psize[0] = float(meta["cdelt2"])
 
     vis = image_to_vis(amap.data, u=u, v=v, pixel_size=new_psize * apu.arcsec/apu.pix)
     vis.offset = new_pos*apu.arcsec
diff --git a/xrayvision/tests/test_imaging.py b/xrayvision/tests/test_imaging.py
index bed82f2..baf27f7 100644
--- a/xrayvision/tests/test_imaging.py
+++ b/xrayvision/tests/test_imaging.py
@@ -110,8 +110,8 @@ def test_map_to_vis(pos, pixel):
     u, v = np.meshgrid(u, v, indexing='ij')
     u, v = np.array([u, v]).reshape(2, size) / apu.arcsec
 
-    header = {'crval1': pos[0].value, 'crval2': pos[1].value,
-              'cdelt1': pixel[0].value, 'cdelt2': pixel[1].value,
+    header = {'crval1': pos[1].value, 'crval2': pos[0].value,
+              'cdelt1': pixel[1].value, 'cdelt2': pixel[0].value,
               'cunit1': 'arcsec', 'cunit2': 'arcsec'}
 
     # Astropy index order is opposite to that of numpy, is 1st dim is across second down
@@ -195,8 +195,8 @@ def test_vis_to_map(m, n, pos, pixel):
     uv = np.array([u, v]).reshape(2, m * n) / apu.arcsec
     u, v = uv
 
-    header = {'crval1': pos[0].value, 'crval2': pos[1].value,
-              'cdelt1': pixel[0].value, 'cdelt2': pixel[1].value,
+    header = {'crval1': pos[1].value, 'crval2': pos[0].value,
+              'cdelt1': pixel[1].value, 'cdelt2': pixel[0].value,
               'cunit1': 'arcsec', 'cunit2': 'arcsec'}
     data = Gaussian2DKernel(2, x_size=n, y_size=m).array
     mp = Map((data, header))
@@ -209,10 +209,10 @@ def test_vis_to_map(m, n, pos, pixel):
     # TODO: figure out why atol is needed here
     assert_allclose(data, res.data, atol=1e-15)
 
-    assert res.reference_coordinate.Tx == pos[0]
-    assert res.reference_coordinate.Ty == pos[1]
-    assert res.scale.axis1 == pixel[0]
-    assert res.scale.axis2 == pixel[1]
+    assert res.reference_coordinate.Tx == pos[1]
+    assert res.reference_coordinate.Ty == pos[0]
+    assert res.scale.axis1 == pixel[1]
+    assert res.scale.axis2 == pixel[0]
     assert res.dimensions.x == m * apu.pix
     assert res.dimensions.y == n * apu.pix