Stix cube

stixpy/product/scratch.py

@@ -1,25 +1,60 @@
 import astropy.units as u
 import numpy as np
+from astropy.nddata import NDUncertainty
 from astropy.time import Time
 from ndcube import NDCube
 from ndcube.extra_coords import QuantityTableCoordinate, TimeTableCoordinate
 
 from stixpy.extern.meta import Meta
 
+
+class PossionUncertainty(NDUncertainty):
+    @property
+    def uncertainty_type(self):
+        return "possion"
+
+    def _data_unit_to_uncertainty_unit(self, value):
+        return value.unit
+
+    def _propagate_add(self, other_uncert, *args, **kwargs):
+        return np.sqrt
+
+    def _propagate_subtract(self, other_uncert, *args, **kwargs):
+        return None
+
+    def _propagate_multiply(self, other_uncert, *args, **kwargs):
+        return None
+
+    def _propagate_divide(self, other_uncert, *args, **kwargs):
+        return None
+
+
 # Lets fake some STIX pixel like data
 pd_shape = (2, 3, 4, 5)  # time, detector, pixel, energy
 pd = np.arange(np.prod(pd_shape)).reshape(pd_shape) * u.ct
 
 # and associated times and quantities
 times = Time("2024-01-01T00:00:00") + np.arange(pd_shape[0]) * 2 * u.s
 energies = (1 + 2 * np.arange(pd_shape[-1])) * u.keV
 
-# Create a gwcs
-energy_coord = QuantityTableCoordinate(energies, names="energy", physical_types="em.energy")
+# Create table coords
 time_coord = TimeTableCoordinate(times, names="time", physical_types="time")
+energy_coord = QuantityTableCoordinate(energies, names="energy", physical_types="em.energy")
+
+# fake coords for detector and pixel
+detector_coord = QuantityTableCoordinate(
+    np.arange(pd_shape[1]) * u.dimensionless_unscaled, names="detector", physical_types="custom:detector"
+)
+pixel_coord = QuantityTableCoordinate(
+    np.arange(pd_shape[2]) * u.dimensionless_unscaled, names="pixel", physical_types="custom:pixel"
+)
+
+combine_coord = energy_coord & pixel_coord & detector_coord & time_coord
 
-combine_coord = time_coord & energy_coord
 
+# I'm not sure what should live in the meta vs extra_coords
 meta = Meta({"detector": ["a", "b", "c"]}, data_shape=pd_shape)
 
 scube = NDCube(data=pd, wcs=combine_coord.wcs, meta=meta)
+scube.extra_coords.add("integration_time", 0, [2, 3] * u.s, physical_types="time.duration")
+scube