13ge_psf_phot.ipynb

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   "id": "reverse-pittsburgh",
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     "end_time": "2021-01-25T21:39:02.133481Z",
     "start_time": "2021-01-25T21:39:01.188986Z"
    }
   },
   "outputs": [
    {
     "name": "stderr",
     "output_type": "stream",
     "text": [
      "WARNING: The fit may be unsuccessful; check fit_info['message'] for more information. [astropy.modeling.fitting]\n"
     ]
    },
    {
     "data": {
      "text/plain": [
       "<GriddedPSFModel(flux=340.83114543, x_0=235.62417096, y_0=246.30749559)>"
      ]
     },
     "execution_count": 1,
     "metadata": {},
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    }
   ],
   "source": [
    "from astropy.modeling.fitting import LevMarLSQFitter\n",
    "from astropy.io import fits\n",
    "from photutils.psf import FittableImageModel\n",
    "from varun_psfutils import make_models\n",
    "#from psf_tools.PSFUtils import make_models  # this suppresses the fit warning!\n",
    "\n",
    "data = fits.getdata('data_cutout.fits')\n",
    "\n",
    "psf_model, _ = make_models('PSFSTD_WFC3UV_F555W.fits')\n",
    "psf_model.flux = 401.348652558488\n",
    "psf_model.x_0 = 235.9156174534438 \n",
    "psf_model.y_0 = 247.0110975634186\n",
    "\n",
    "yy, xx = np.mgrid[242:253, 231:242]\n",
    "fitter = LevMarLSQFitter()\n",
    "fit_psf = fitter(psf_model, xx, yy, data)\n",
    "fit_psf"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "id": "therapeutic-billy",
   "metadata": {
    "ExecuteTime": {
     "end_time": "2021-01-25T21:39:02.139457Z",
     "start_time": "2021-01-25T21:39:02.135930Z"
    }
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'Number of calls to function has reached maxfev = 100.'"
      ]
     },
     "execution_count": 2,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "fitter.fit_info['message']"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "id": "induced-aside",
   "metadata": {
    "ExecuteTime": {
     "end_time": "2021-01-25T21:39:02.146893Z",
     "start_time": "2021-01-25T21:39:02.143301Z"
    }
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "True"
      ]
     },
     "execution_count": 3,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "fitter.fit_info['param_cov'] is None"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "consecutive-thermal",
   "metadata": {},
   "outputs": [],
   "source": []
  }
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