diff options
Diffstat (limited to 'stwcs/distortion/coeff_converter.py')
| -rw-r--r-- | stwcs/distortion/coeff_converter.py | 43 |
1 files changed, 22 insertions, 21 deletions
diff --git a/stwcs/distortion/coeff_converter.py b/stwcs/distortion/coeff_converter.py index 415b512..99cf74d 100644 --- a/stwcs/distortion/coeff_converter.py +++ b/stwcs/distortion/coeff_converter.py @@ -1,9 +1,10 @@ -from __future__ import division, print_function # confidence high +from __future__ import (absolute_import, unicode_literals, division, print_function) import numpy as np from astropy.io import fits from astropy import wcs as pywcs + def sip2idc(wcs): """ Converts SIP style coefficients to IDCTAB coefficients. @@ -49,28 +50,28 @@ def sip2idc(wcs): print('Input to sip2idc must be a PyFITS header or a wcsutil.HSTWCS object\n') return - if None in [ocx10, ocx11, ocy10, ocy11]: print('First order IDC coefficients not found, exiting ...\n') return None, None idc_coeff = np.array([[ocx11, ocx10], [ocy11, ocy10]]) - cx = np.zeros((order+1,order+1), dtype=np.double) - cy = np.zeros((order+1,order+1), dtype=np.double) - for n in range(order+1): - for m in range(order+1): - if n >= m and n>=2: - sipval = np.array([[sipa[m,n-m]],[sipb[m,n-m]]]) + cx = np.zeros((order + 1, order + 1), dtype=np.double) + cy = np.zeros((order + 1, order + 1), dtype=np.double) + for n in range(order + 1): + for m in range(order + 1): + if n >= m and n >= 2: + sipval = np.array([[sipa[m, n - m]], [sipb[m, n - m]]]) idcval = np.dot(idc_coeff, sipval) - cx[n,m] = idcval[0] - cy[n,m] = idcval[1] + cx[n, m] = idcval[0] + cy[n, m] = idcval[1] - cx[1,0] = ocx10 - cx[1,1] = ocx11 - cy[1,0] = ocy10 - cy[1,1] = ocy11 + cx[1, 0] = ocx10 + cx[1, 1] = ocx11 + cy[1, 0] = ocy10 + cy[1, 1] = ocy11 return cx, cy + def _read_sip_kw(header): """ Reads SIP header keywords and returns an array of coefficients. @@ -84,15 +85,15 @@ def _read_sip_kw(header): "keyword for SIP distortion") m = int(header["A_ORDER"]) - a = np.zeros((m+1, m+1), np.double) - for i in range(m+1): - for j in range(m-i+1): + a = np.zeros((m + 1, m + 1), np.double) + for i in range(m + 1): + for j in range(m - i + 1): a[i, j] = header.get("A_%d_%d" % (i, j), 0.0) m = int(header["B_ORDER"]) - b = np.zeros((m+1, m+1), np.double) - for i in range(m+1): - for j in range(m-i+1): + b = np.zeros((m + 1, m + 1), np.double) + for i in range(m + 1): + for j in range(m - i + 1): b[i, j] = header.get("B_%d_%d" % (i, j), 0.0) elif "B_ORDER" in header: raise ValueError( @@ -102,7 +103,7 @@ def _read_sip_kw(header): a = None b = None - return a , b + return a, b """ |