point_source function to be used with an arbitrary spectra, other min…

…or changes

scopesim_templates/calibration/calibration.py

@@ -1,9 +1,12 @@
 import numpy as np
 from astropy import units as u
 from astropy.io import fits
+
+from spextra import Spextrum
+
 from scopesim_templates.rc import Source, __config__
 from scopesim_templates.utils.general_utils import function_call_str, make_img_wcs_header
-from spextra import Spextrum
+from ..misc.misc import uniform_source
 
 
 def flat_field(temperature=5000, amplitude=0*u.ABmag, filter_curve="V", extend=60):
@@ -35,18 +38,11 @@ def flat_field(temperature=5000, amplitude=0*u.ABmag, filter_curve="V", extend=6
     """
 
     sp = Spextrum.black_body_spectrum(temperature=temperature, amplitude=amplitude, filter_curve=filter_curve)
-
-    if isinstance(amplitude, u.Quantity) is False:
-        amplitude = amplitude * u.ABmag
-
-    data = np.ones(shape=(extend, extend))
-    header = make_img_wcs_header(ra=0, dec=0, pixel_scale=1, image_size=data.shape)
-    hdu = fits.ImageHDU(header=header, data=data)
-
-    src = Source(spectra=sp, image_hdu=hdu)
+    src = uniform_source(sed=sp, amplitude=amplitude, filter_curve=filter_curve, extend=extend)
 
     return src
 
+
 def empty_sky():
     """
     Returns an empty source so that instrumental fluxes can be simulated

scopesim_templates/misc/misc.py

@@ -6,6 +6,7 @@
 from astropy import units as u
 from astropy.wcs import WCS
 from astropy.utils.decorators import deprecated_renamed_argument
+from astropy.table import Table
 
 from synphot import SourceSpectrum, Empirical1D
 
@@ -14,33 +15,59 @@
 from ..utils import general_utils as gu
 
 
-def homogeneous_source(sed, amplitude=15, filter_curve="V", extend=60, ra=gu.RA0, dec=gu.DEC0):
+def point_source(sed, amplitude=None, filter_curve="V", x=0, y=0, ra=gu.RA0, dec=gu.DEC0):
+
+    if (isinstance(amplitude, u.Quantity)) is False and amplitude is not None:
+        amplitude = amplitude * u.ABmag
+    if isinstance(sed, str):
+        sp = Spextrum(sed)
+        scaled_sp = sp.scale_to_magnitude(amplitude=amplitude, filter_curve=filter_curve)
+    elif isinstance(sed, (Spextrum, SourceSpectrum)):
+        sp = Spextrum(modelclass=sed)
+        if amplitude is None:
+            scaled_sp = sp
+        else:
+            scaled_sp = sp.scale_to_magnitude(amplitude=amplitude, filter_curve=filter_curve)
+
+    src = Source(spectra=scaled_sp, x=[x], y=[y], ref=[0], weight=[1])
+    return src
+
+
+def uniform_source(sed, amplitude=None, filter_curve="V", extend=60, ra=gu.RA0, dec=gu.DEC0):
     """
-    Creates a homogeneous source with an arbitrary spectrum
+    Creates a extended uniform source with an arbitrary spectrum
 
     sed : synphot or spextra sed
-    amplitude : magnitude or flux of the spectrum in the filter_curve
+    amplitude : magnitude or flux (PER ARCSEC^2) of the spectrum in the specified filter_curve
     filter_curve : any filter curve
+    extend : int
+        extension of the field in arcsec, will always produce an square field
+    ra : RA
+    dec : DEC
     """
-    if isinstance(amplitude, u.Quantity) is False:
+    if (isinstance(amplitude, u.Quantity)) is False and amplitude is not None:
         amplitude = amplitude * u.ABmag
     if isinstance(sed, str):
         sp = Spextrum(sed)
         scaled_sp = sp.scale_to_magnitude(amplitude=amplitude, filter_curve=filter_curve)
     elif isinstance(sed, (Spextrum, SourceSpectrum)):
         sp = Spextrum(modelclass=sed)
-        scaled_sp = sp.scale_to_magnitude(amplitude=amplitude, filter_curve=filter_curve)
+        if amplitude is None:
+            scaled_sp = sp
+        else:
+            scaled_sp = sp.scale_to_magnitude(amplitude=amplitude, filter_curve=filter_curve)
 
     data = np.ones(shape=(extend, extend))
-    header = gu.make_img_wcs_header(ra=ra, dec=ra, pixel_scale=1, image_size=data.shape)
+
+    header = gu.make_img_wcs_header(ra=ra, dec=dec, pixel_scale=1, image_size=data.shape)
     hdu = fits.ImageHDU(header=header, data=data)
 
     src = Source(spectra=scaled_sp, image_hdu=hdu)
 
     return src
 
 
-def source_from_imagehdu(image_hdu, filter_name, pixel_unit_amplitude=None,
+def source_from_imagehdu(image_hdu, filter_name, pixel_unit_amplitude=None, waverange=None,
                          inst_pkg_path=None):
     """
     Creates a scopesim.Source object directly from an fits.ImageHDU
@@ -50,6 +77,8 @@ def source_from_imagehdu(image_hdu, filter_name, pixel_unit_amplitude=None,
     image_hdu : fits.ImageHDU
     filter_name : str
         Either a standard filter name or a filter from an instrument package
+    waverange: tuple
+        wave_min and wave_max of the spectral range
     pixel_unit_amplitude, optional
         A Quantity that corresponds to a pixel value of 1 in the image
         If not given, header keyword BUNIT is used

scopesim_templates/stellar/stars.py

@@ -151,6 +151,9 @@ def stars(filter_name, amplitudes, spec_types, x, y, library="pyckles", ra=RA0,
         the spectral type(s) of the stars, e.g. "A0V", "G5III"
     x, y : arrays of float
         [arcsec] x and y coordinates of the stars on the focal plane
+    ra, dec : float
+        coordinates of the center of the field
+
 
     library: str
         Library where the spectroscopic types are taken. By default are taken from the pickles library using

scopesim_templates/tests/test_misc/test_misc.py

@@ -1,5 +1,6 @@
 from os.path import exists
 import pytest
+import synphot
 from pytest import raises
 from astropy import units as u
 from astropy.io import fits
@@ -51,11 +52,36 @@ def test_is_happy_with_metis_filter_and_bunit(self):
         assert isinstance(src, Source)
 
 
+class TestPointSource:
+    def test_initialize_from_spextra(self):
+        src = misc.point_source("pickles/a0v", amplitude=16)
+
+        assert isinstance(src, Source)
+
+    def test_initialize_from_synphot(self):
+        sp = synphot.SourceSpectrum(synphot.Empirical1D, points=[1000, 10000], lookup_table=[1, 1])
+        src = misc.point_source(sed=sp)
+        assert isinstance(src, Source)
+
+
+class TestUniformSource:
+    def test_initialize_from_spextra(self):
+        src = misc.uniform_source("pickles/a0v", amplitude=16)
+
+        assert isinstance(src, Source)
+
+    def test_initialize_from_synphot(self):
+        sp = synphot.SourceSpectrum(synphot.Empirical1D, points=[1000, 10000], lookup_table=[1, 1])
+        src = misc.uniform_source(sed=sp)
+        assert isinstance(src, Source)
+
+
 def test_poorman_cube_source_is_working():
     cube = so._make_dummy_cube(scale=0.2, wave_unit=u.AA, ref_wave=5000,
                             wave_step=1, wave_type="WAVE", bunit="erg / (s cm2 Angstrom)")
 
     hdul = fits.HDUList(cube)
     cube_source = misc.poorman_cube_source(hdu=hdul, ext=0)
 
-    assert isinstance(cube_source, Source)
+    assert isinstance(cube_source, Source)
+