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Diffstat (limited to 'distortion/coeff_converter.py')
| -rw-r--r-- | distortion/coeff_converter.py | 141 |
1 files changed, 0 insertions, 141 deletions
diff --git a/distortion/coeff_converter.py b/distortion/coeff_converter.py deleted file mode 100644 index f2eb4ad..0000000 --- a/distortion/coeff_converter.py +++ /dev/null @@ -1,141 +0,0 @@ -from __future__ import division # confidence high - -import numpy as np -import pyfits -import pywcs - -def sip2idc(wcs): - """ - Converts SIP style coefficients to IDCTAB coefficients. - - :Parameters: - `wcs`: pyfits.Header or pywcs.WCS object - """ - if isinstance(wcs,pyfits.Header): - ocx10 = wcs.get('OCX10', None) - ocx11 = wcs.get('OCX11', None) - ocy10 = wcs.get('OCY10', None) - ocy11 = wcs.get('OCY11', None) - order = wcs.get('A_ORDER', None) - sipa, sipb = _read_sip_kw(wcs) - if None in [ocx10, ocx11, ocy10, ocy11, sipa, sipb]: - print 'Cannot convert SIP to IDC coefficients.\n' - return None, None - elif isinstance(wcs,pywcs.WCS): - try: - ocx10 = wcs.ocx10 - ocx11 = wcs.ocx11 - ocy10 = wcs.ocy10 - ocy11 = wcs.ocy11 - except AttributeError: - print 'First order IDCTAB coefficients are not available.\n' - print 'Cannot convert SIP to IDC coefficients.\n' - return None, None - try: - sipa = wcs.sip.a - sipb = wcs.sip.b - except AttributeError: - print 'SIP coefficients are not available.' - print 'Cannot convert SIP to IDC coefficients.\n' - return None, None - try: - order = wcs.sip.a_order - except AttributeError: - print 'SIP model order unknown, exiting ...\n' - return None, None - - else: - 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 - 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]]]) - idcval = np.dot(idc_coeff, sipval) - 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 - - return cx, cy - -def _read_sip_kw(header): - """ - Reads SIP header keywords and returns an array of coefficients. - - If no SIP header keywords are found, None is returned. - """ - if header.has_key("A_ORDER"): - if not header.has_key("B_ORDER"): - raise ValueError( - "A_ORDER provided without corresponding B_ORDER " - "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[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[i, j] = header.get("B_%d_%d" % (i, j), 0.0) - elif header.has_key("B_ORDER"): - raise ValueError( - "B_ORDER provided without corresponding A_ORDER " - "keyword for SIP distortion") - else: - a = None - b = None - - return a , b - - -""" -def idc2sip(wcsobj, idctab = None): - if isinstance(wcs,pywcs.WCS): - try: - cx10 = wcsobj.ocx10 - cx11 = wcsobj.cx11 - cy10 = wcsobj.cy10 - cy11 = wcsobj.cy11 - except AttributeError: - print - try: - order = wcs.sip.a_order - except AttributeError: - print 'SIP model order unknown, exiting ...\n' - return - else: - 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 - idc_coeff = np.array([[wcsobj.cx11, wcsobj.cx10], [wcsobj.cy11, wcsobj.cy10]]) - cx = numpy.zeros((order+1,order+1), dtype=numpy.double) - cy = numpy.zeros((order+1,order+1), dtype=numpy.double) - for n in range(order+1): - for m in range(order+1): - if n >= m and n>=2: - sipval = numpy.array([[wcsobj.sip.a[n,m]],[wcsobj.sip.b[n,m]]]) - idcval = numpy.dot(idc_coeff, sipval) - cx[m,n-m] = idcval[0] - cy[m,n-m] = idcval[1] - - return cx, cy -"""
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