JP-2096: Cube build stage3

CHANGES.rst

@@ -17,6 +17,8 @@ cube_build
 ----------
 
 - Fix bug when creating cubes using output_type=channel. [#6138]
+- Move computationally intensive routines to c extensions and
+  removed miri psf weight function. [#6093]
 
 datamodels
 ----------

jwst/cube_build/blot_cube.py

@@ -0,0 +1,50 @@
+""" Map the detector pixels to the cube coordinate system.
+This is where the weight functions are used.
+"""
+import numpy as np
+import logging
+log = logging.getLogger(__name__)
+log.setLevel(logging.DEBUG)
+
+
+def blot_overlap(ipt, xstart,
+                 xcenter, ycenter,
+                 x_cube, y_cube,
+                 flux_cube,
+                 blot_xsize,
+                 blot_flux, blot_weight):
+
+    """ Blot the median sky image back to the detector
+
+    ipt is the median element.
+    xcenter, ycenter are the detector pixel arrays
+    xstart is only valid for MIRI and is the start of the x detector value for channel
+          0  for channels on left and ~512 for channels on right
+    x_cube, y_cube:  median cube IFU mapped backwards to detector
+    flux_cube: median flux
+    blot_flux & blot_weight: blotted values of flux_cube to detector
+    """
+
+    roi_det = 1.0  # Just large enough that we don't get holes
+    xdistance = np.absolute(x_cube[ipt] - xcenter)
+    ydistance = np.absolute(y_cube[ipt] - ycenter)
+
+    index_x = np.where(xdistance <= roi_det)
+    index_y = np.where(ydistance <= roi_det)
+
+    if len(index_x[0]) > 0 and len(index_y[0]) > 0:
+
+        d1pix = x_cube[ipt] - xcenter[index_x]
+        d2pix = y_cube[ipt] - ycenter[index_y]
+
+        dxy = [(dx * dx + dy * dy) for dy in d2pix for dx in d1pix]
+        dxy = np.array(dxy)
+        dxy = np.sqrt(dxy)
+        weight_distance = np.exp(-dxy)
+        weighted_flux = weight_distance * flux_cube[ipt]
+
+        index2d = [iy * blot_xsize + ix for iy in index_y[0] for ix in (index_x[0] + xstart)]
+        index2d = np.array(index2d)
+
+        blot_flux[index2d] = blot_flux[index2d] + weighted_flux
+        blot_weight[index2d] = blot_weight[index2d] + weight_distance

jwst/cube_build/blot_cube_build.py

@@ -8,6 +8,8 @@
 from gwcs import wcstools
 from . import instrument_defaults
 
+from . import blot_cube
+
 log = logging.getLogger(__name__)
 log.setLevel(logging.DEBUG)
 
@@ -199,16 +201,15 @@ def blot_images_miri(self):
             # pixel.
             # the Regular grid is on the x,y detector
 
-            blot_flux = self.blot_overlap_quick(model, xcenter, ycenter,
-                                                xstart, x_cube, y_cube,
-                                                flux_cube)
+            blot_flux = self.blot_overlap_miri(model, xcenter, ycenter,
+                                               xstart, x_cube, y_cube,
+                                               flux_cube)
             blot.data = blot_flux
             blot_models.append(blot)
         return blot_models
-    # ________________________________________________________________________________
 
-    def blot_overlap_quick(self, model, xcenter, ycenter, xstart,
-                           x_cube, y_cube, flux_cube):
+    def blot_overlap_miri(self, model, xcenter, ycenter, xstart,
+                          x_cube, y_cube, flux_cube):
 
         # blot_overlap_quick finds to overlap between the blotted sky values
         # (x_cube, y_cube) and the detector pixels.
@@ -223,31 +224,16 @@ def blot_overlap_quick(self, model, xcenter, ycenter, xstart,
         blot_weight = np.ndarray.flatten(blot_weight)
 
         # loop over valid points in cube (not empty edge pixels)
-        roi_det = 1.0  # Just large enough that we don't get holes
-        ivalid = np.nonzero(np.absolute(flux_cube))
 
+        ivalid = np.nonzero(np.absolute(flux_cube))
         t0 = time.time()
         for ipt in ivalid[0]:
-            # search xcenter and ycenter seperately. These arrays are smallsh.
-            # xcenter size = naxis1 on detector (for MIRI only 1/2 array)
-            # ycenter size = naxis2 on detector
-            xdistance = np.absolute(x_cube[ipt] - xcenter)
-            ydistance = np.absolute(y_cube[ipt] - ycenter)
-
-            index_x = np.where(xdistance <= roi_det)
-            index_y = np.where(ydistance <= roi_det)
-
-            if len(index_x[0]) > 0 and len(index_y[0]) > 0:
-                d1pix = np.array(x_cube[ipt] - xcenter[index_x])
-                d2pix = np.array(y_cube[ipt] - ycenter[index_y])
-
-                dxy = [(dx * dx + dy * dy) for dy in d2pix for dx in d1pix]
-                dxy = np.sqrt(dxy)
-                weight_distance = np.exp(-dxy)
-                weighted_flux = weight_distance * flux_cube[ipt]
-                index2d = [iy * blot_xsize + ix for iy in index_y[0] for ix in (index_x[0] + xstart)]
-                blot_flux[index2d] = blot_flux[index2d] + weighted_flux
-                blot_weight[index2d] = blot_weight[index2d] + weight_distance
+            blot_cube.blot_overlap(ipt, xstart,
+                                   xcenter, ycenter,
+                                   x_cube, y_cube,
+                                   flux_cube,
+                                   blot_xsize,
+                                   blot_flux, blot_weight)
 
         t1 = time.time()
         log.debug(f"Time to blot median image to input model =  {t1-t0:.1f}")
@@ -257,7 +243,6 @@ def blot_overlap_quick(self, model, xcenter, ycenter, xstart,
         blot_flux = blot_flux.reshape((blot_ysize, blot_xsize))
         return blot_flux
 
-    # ************************************************************************
     def blot_images_nirspec(self):
         """ Core blotting routine for NIRSPEC
 
@@ -299,7 +284,7 @@ def blot_images_nirspec(self):
             nslices = 30
             log.info('Looping over 30 slices on NIRSPEC detector, this takes a little while')
             t0 = time.time()
-            roi_det = 1.0  # Just large enough that we don't get holes
+
             for ii in range(nslices):
                 ts0 = time.time()
                 # for each slice pull out the blotted values that actually fall on the slice region
@@ -338,30 +323,17 @@ def blot_images_nirspec(self):
                 y_slice = y_slice[fuse]
                 flux_slice = flux_slice[fuse]
 
+                xstart = 0
                 nn = flux_slice.size
                 for ipt in range(nn):
-                    # search xcenter and ycenter seperately. These arrays are smallish.
-                    # xcenter size = naxis1 on detector
-                    # ycenter size = naxis2 on detector
-                    xdistance = np.absolute(x_slice[ipt] - xcenter)
-                    ydistance = np.absolute(y_slice[ipt] - ycenter)
-
-                    index_x = np.where(xdistance <= roi_det)
-                    index_y = np.where(ydistance <= roi_det)
-
-                    if len(index_x[0]) > 0 and len(index_y[0]) > 0:
-                        d1pix = np.array(x_slice[ipt] - xcenter[index_x])
-                        d2pix = np.array(y_slice[ipt] - ycenter[index_y])
-
-                        dxy = [(dx * dx + dy * dy) for dy in d2pix for dx in d1pix]
-                        dxy = np.sqrt(dxy)
-                        weight_distance = np.exp(-dxy)
-                        weighted_flux = weight_distance * flux_slice[ipt]
-                        index2d = [iy * blot_xsize + ix for iy in index_y[0] for ix in (index_x[0])]
-                        blot_flux[index2d] = blot_flux[index2d] + weighted_flux
-                        blot_weight[index2d] = blot_weight[index2d] + weight_distance
+                    blot_cube.blot_overlap(ipt, xstart,
+                                           xcenter, ycenter,
+                                           x_slice, y_slice,
+                                           flux_slice,
+                                           blot_xsize,
+                                           blot_flux, blot_weight)
                 ts1 = time.time()
-                log.debug(f"Time to map 1 slice  =  {ts1-ts0:.1f}")
+                log.debug(f"Time to blot 1 slice on NIRspec  =  {ts1-ts0:.1f}")
             # done mapping median cube  to this input model
             t1 = time.time()
             log.debug(f"Time to blot median image to input model =  {t1-t0:.1f}")

jwst/cube_build/cube_build.py

@@ -18,7 +18,6 @@ def __init__(self,
                  input_models,
                  input_filenames,
                  par_filename,
-                 resol_filename,
                  **pars):
         """ Initialize the high level of information for the ifu cube
 
@@ -36,15 +35,12 @@ def __init__(self,
           list of fits filenames
         par_filename: str
           cube parameter reference filename
-        resol_filename: str
-          miri resolution reference filename
         pars : dictionary holding top level cube parameters
         """
 
         self.input_models = input_models
         self.input_filenames = input_filenames
         self.par_filename = par_filename
-        self.resol_filename = resol_filename
         self.single = pars.get('single')
         self.channel = pars.get('channel')
         self.subchannel = pars.get('subchannel')
@@ -73,7 +69,6 @@ def setup(self):
 
         Read in necessary reference data:
         * cube parameter reference file
-        * if miripsf weighting parameter is set then read in resolution file
 
         This routine fills in the instrument_info dictionary, which holds the
         default spatial and spectral size of the output cube, as well as,
@@ -117,15 +112,6 @@ def setup(self):
                                          self.all_filter,
                                          instrument_info)
 # -------------------------------------------------------------------------------
-# Read the miri resolution reference file
-        if self.weighting == 'miripsf':
-            log.info('Reading default MIRI cube resolution file %s',
-                     self.resol_filename)
-            cube_build_io_util.read_resolution_file(self.resol_filename,
-                                                    self.all_channel,
-                                                    self.all_subchannel,
-                                                    instrument_info)
-# _______________________________________________________________________________
         self.instrument_info = instrument_info
 # _______________________________________________________________________________
 # Set up values to return and acess for other parts of cube_build

jwst/cube_build/cube_build_step.py

@@ -41,7 +41,7 @@ class CubeBuildStep (Step):
          scale1 = float(default=0.0) # cube sample size to use for axis 1, arc seconds
          scale2 = float(default=0.0) # cube sample size to use for axis 2, arc seconds
          scalew = float(default=0.0) # cube sample size to use for axis 3, microns
-         weighting = option('emsm','msm','miripsf',default = 'emsm') # Type of weighting function
+         weighting = option('emsm','msm',default = 'emsm') # Type of weighting function
          coord_system = option('skyalign','world','internal_cal','ifualign',default='skyalign') # Output Coordinate system.
          rois = float(default=0.0) # region of interest spatial size, arc seconds
          roiw = float(default=0.0) # region of interest wavelength size, microns
@@ -57,7 +57,7 @@ class CubeBuildStep (Step):
          output_use_model = boolean(default=true) # Use filenames in the output models
        """
 
-    reference_file_types = ['cubepar', 'resol']
+    reference_file_types = ['cubepar']
 
 # ________________________________________________________________________________
     def process(self, input):
@@ -140,7 +140,7 @@ def process(self, input):
         # if interpolation is point cloud then weighting can be
         # 1. MSM: modified shepard method
         # 2. EMSM
-        # 3. miripsf - weighting for MIRI based on PSF and LSF
+
         if self.coord_system == 'skyalign':
             self.interpolation = 'pointcloud'
 
@@ -221,16 +221,6 @@ def process(self, input):
             self.log.warning('No default cube parameters reference file found')
             return
 # ________________________________________________________________________________
-# If miripsf weight is set then set up reference file
-        resol_filename = None
-        if self.weighting == 'miripsf':
-            resol_filename = self.get_reference_file(self.input_models[0], 'resol')
-            self.log.info(f'MIRI resol reference file {resol_filename}')
-            if resol_filename == 'N/A':
-                self.log.warning('No spectral resolution reference file found')
-                self.log.warning('Run again and turn off miripsf')
-                return
-# ________________________________________________________________________________
 # shove the input parameters in to pars to pull out in general cube_build.py
 
         pars = {
@@ -269,7 +259,6 @@ def process(self, input):
             self.input_models,
             self.input_filenames,
             par_filename,
-            resol_filename,
             **pars)
 # ________________________________________________________________________________
 # cubeinfo.setup:

jwst/cube_build/cube_build_wcs_util.py

@@ -111,27 +111,19 @@ def find_corners_MIRI(input, this_channel, instrument_info, coord_system):
     lambda_min = np.nanmin(lam)
     lambda_max = np.nanmax(lam)
 
-    # before returning,  ra should be between 0 to 360
-    if a_min < 0:
-        a_min = a_min + 360
-    if a_max >= 360.0:
-        a_max = a_max - 360.0
-
-    if a1 < 0:
-        a1 = a1 + 360
-    if a1 > 360.0:
-        a1 = a1 - 360.0
-
-    if a2 < 0:
-        a2 = a2 + 360
-    if a2 > 360.0:
-        a2 = a2 - 360.0
+    if coord_system != 'internal_cal':
+        # before returning,  ra should be between 0 to 360
+        a_min %= 360
+        a_max %= 360
+
+        a1 %= 360
+        a2 %= 360
 
     return a_min, b1, a_max, b2, a1, b_min, a2, b_max, lambda_min, lambda_max
 # *****************************************************************************
 
 
-def find_corners_NIRSPEC(input, this_channel, instrument_info, coord_system):
+def find_corners_NIRSPEC(input, instrument_info, coord_system):
     """Find the sky footprint of a slice of a NIRSpec exposure
 
     For each slice find:
@@ -241,5 +233,5 @@ def find_corners_NIRSPEC(input, this_channel, instrument_info, coord_system):
 
     lambda_min = min(lambda_slice)
     lambda_max = max(lambda_slice)
+
     return a_min, b1, a_max, b2, a1, b_min, a2, b_max, lambda_min, lambda_max
-# ______________________________________________________________________________