Add option to have correctly-ordered limits in tiled dataset plot

dkist/dataset/tiled_dataset.py

@@ -10,10 +10,12 @@
 
 import matplotlib.pyplot as plt
 import numpy as np
+from matplotlib.axes import Axes
 from matplotlib.gridspec import GridSpec
 
 import astropy
 from astropy.table import vstack
+from astropy.wcs.wcsapi import HighLevelWCSWrapper
 
 from dkist.io.file_manager import FileManager, StripedExternalArray
 from dkist.io.loaders import AstropyFITSLoader
@@ -168,7 +170,26 @@ def _get_axislabels(ax):
                 ylabel = coord.get_axislabel() or coord._get_default_axislabel()
         return (xlabel, ylabel)
 
-    def plot(self, slice_index, share_zscale=False, fig=None, **kwargs):
+    @staticmethod
+    def _ensure_wcs_ordered_axis_lims(wcs: HighLevelWCSWrapper, ax: Axes) -> None:
+        """
+        Adjust axis limits so the WCS values go from smaller numbers in the bottom left to higher numbers in the upper right.
+        """
+        xmin, xmax = ax.get_xlim()
+        ymin, ymax = ax.get_ylim()
+
+        world_xmin, world_ymin = wcs.low_level_wcs.pixel_to_world_values(xmin, ymin)
+        world_xmax, world_ymax = wcs.low_level_wcs.pixel_to_world_values(xmax, ymax)
+
+        new_xmin, new_ymin = wcs.low_level_wcs.world_to_pixel_values(min(world_xmin, world_xmax), min(world_ymin, world_ymax))
+        new_xmax, new_ymax = wcs.low_level_wcs.world_to_pixel_values(max(world_xmin, world_xmax), max(world_ymin, world_ymax))
+
+        ax.set_xlim(new_xmin, new_xmax)
+        ax.set_ylim(new_ymin, new_ymax)
+
+        return
+
+    def plot(self, slice_index, share_zscale=False, fig=None, limits_from_wcs=True, **kwargs):
         """
         Plot a slice of each tile in the TiledDataset
 
@@ -185,6 +206,9 @@ def plot(self, slice_index, share_zscale=False, fig=None, **kwargs):
         fig : `matplotlib.figure.Figure`
             A figure to use for the plot. If not specified the current pyplot
             figure will be used, or a new one created.
+        limits_from_wcs : `bool`
+           If ``True`` the plots will be adjusted so smaller WCS values in the lower left, increasing to the upper
+           right. If ``False`` then the raw orientation of the data is used.
         """
         if isinstance(slice_index, int):
             slice_index = (slice_index,)
@@ -202,6 +226,10 @@ def plot(self, slice_index, share_zscale=False, fig=None, **kwargs):
                 ax_gridspec = gridspec[dataset_nrows - row - 1, col]
                 ax = fig.add_subplot(ax_gridspec, projection=tile.wcs)
                 tile.plot(axes=ax, **kwargs)
+
+                if limits_from_wcs:
+                    self._ensure_wcs_ordered_axis_lims(tile.wcs, ax)
+
                 if col == row == 0:
                     xlabel, ylabel = self._get_axislabels(ax)
                     fig.supxlabel(xlabel, y=0.05)