ENH enable gsobjects from eval (#20)

montara/__init__.py

@@ -18,3 +18,4 @@
 from . import mixed_scene_postop  # noqa
 from . import badpixfromfits  # noqa
 from . import eastlake_step  # noqa
+from . import eval_gsobject  # noqa

montara/des_tile.py

@@ -901,6 +901,7 @@ def buildImages(
                    'rejectlist_file', 'dither_scale', 'coadd_wcs', 'n_se_test',
                    'grid_border']
         ignore += ['file_name', 'dir']
+        ignore += ['analyze_with_interpimage_psf']
         logger.debug("current mag_zp: %f" % base["eval_variables"]["fmag_zp"])
 
         # We are making sure to call the OutputBuilder from galsim

montara/eastlake_step.py

@@ -198,7 +198,20 @@ def update_stash(self, config, stash):
             stash["rejectlist"] = rejectlist.rejectlist_data
 
         # Add the PSF config
-        stash["psf_config"] = config["psf"]
+        if config["output"].get("analyze_with_interpimage_psf", False):
+            import copy
+            _psf, safe = galsim.config.BuildGSObject({'blah': copy.deepcopy(config["psf"])}, 'blah')
+            assert safe, "PSF model must be reusable (safe) to use as an InterpolatedImage"
+            _psf = _psf.withFlux(1.0).drawImage(nx=25, ny=25, scale=0.263)
+            _psf = galsim.InterpolatedImage(_psf, x_interpolant='lanczos15')
+            with np.printoptions(threshold=np.inf, precision=32):
+                _psf = repr(_psf)
+            stash["psf_config"] = {
+                "type": "Eval",
+                "str": _psf.replace("array(", "np.array("),
+            }
+        else:
+            stash["psf_config"] = config["psf"]
         # add draw_method if present
         if "draw_method" in config["stamp"]:
             stash["draw_method"] = config["stamp"]["draw_method"]

montara/eval_gsobject.py

@@ -0,0 +1,10 @@
+import galsim
+
+
+def EvalGSObject(config, base, ignore, gsparams, logger):
+    req = {'str': str}
+    params, safe = galsim.config.GetAllParams(config, base, req=req, ignore=ignore)
+    return galsim.utilities.math_eval(params['str']).withGSParams(**gsparams), safe
+
+
+galsim.config.RegisterObjectType('Eval', EvalGSObject)

montara/tests/test_eval_gsobject.py

@@ -0,0 +1,16 @@
+import galsim
+import numpy as np
+
+
+def test_build_gsobject_evalrepr():
+    g = galsim.Gaussian(fwhm=1.0).drawImage(nx=25, ny=25, scale=0.263)
+    ii = galsim.InterpolatedImage(g, x_interpolant='lanczos15')
+    with np.printoptions(threshold=np.inf, precision=32):
+        r = repr(ii)
+    cfg = {
+        "type": "Eval",
+        "str": r.replace("array(", "np.array("),
+    }
+    rii, safe = galsim.config.BuildGSObject({'blah': cfg}, 'blah')
+    assert safe
+    assert rii == ii

ruff.toml

@@ -0,0 +1,2 @@
+# Allow lines to be as long as 120 characters.
+line-length = 120