compute_approx_psf_size_and_shape¶
- lsst.pipe.tasks.healSparseMappingProperties.compute_approx_psf_size_and_shape(ccd_row, ra, dec, nx=20, ny=20, orderx=2, ordery=2)¶
Compute the approximate psf size and shape.
This routine fits how the psf size and shape varies over a field by approximating with a Chebyshev bounded field.
- Parameters:
- ccd_row
lsst.afw.table.ExposureRecord Exposure metadata for a given detector exposure.
- ra
np.ndarray Right ascension of points to compute size and shape (degrees).
- dec
np.ndarray Declination of points to compute size and shape (degrees).
- nx
int, optional Number of sampling points in the x direction.
- ny
int, optional Number of sampling points in the y direction.
- orderx
int, optional Chebyshev polynomial order for fit in x direction.
- ordery
int, optional Chebyshev polynomial order for fit in y direction.
- ccd_row
- Returns:
- psf_array
np.ndarray Record array with “psf_size”, “psf_e1”, “psf_e2”.
- psf_array