diff options
| -rw-r--r-- | wcsutil/__init__.py | 11 | ||||
| -rw-r--r-- | wcsutil/altwcs.py | 14 | ||||
| -rw-r--r-- | wcsutil/hstwcs.py | 131 |
3 files changed, 94 insertions, 62 deletions
diff --git a/wcsutil/__init__.py b/wcsutil/__init__.py index 2b74a9c..2b7dbcd 100644 --- a/wcsutil/__init__.py +++ b/wcsutil/__init__.py @@ -9,7 +9,9 @@ from hstwcs import HSTWCS __docformat__ = 'restructuredtext' __version__ = '0.8' - +""" +Example go here +""" def help(): print 'How to create an HSTWCS object:\n\n' @@ -27,8 +29,13 @@ def help(): 3. Create an HSTWCS object using a file name and an extension number. \n Example:\n w = wcsutil.HSTWCS('j9irw4b1q_flt.fits', ext=2)\n\n + + 4. Create an HSTWCS object from WCS with key 'O'.\n + Example:\n - 4. Create a template HSTWCS object for a DEFAULT object.\n + w = wcsutil.HSTWCS('j9irw4b1q_flt.fits', ext=2, wcskey='O')\n\n + + 5. Create a template HSTWCS object for a DEFAULT object.\n Example:\n w = wcsutil.HSTWCS(instrument='DEFAULT')\n\n """ diff --git a/wcsutil/altwcs.py b/wcsutil/altwcs.py index 4cfb033..42a2d67 100644 --- a/wcsutil/altwcs.py +++ b/wcsutil/altwcs.py @@ -290,9 +290,11 @@ def wcskeys(header): def wcsnames(header): """ - Purpose - ======= - Return a dictionary of wcskey: WCSNAME pairs + Returns a dictionary of wcskey: WCSNAME pairs + + Parameters + ---------- + header: pyfits.Header """ names = header["WCSNAME*"] d = {} @@ -340,6 +342,12 @@ def getKeyFromName(header, wcsname): If WCSNAME is found in header, return its key, else return None. This is used to update an alternate WCS repeatedly and not generate new keys every time. + + Parameters + ---------- + header: pyfits.Header + wcsname: str + Value of WCSNAME """ wkey = None names = wcsnames(header) diff --git a/wcsutil/hstwcs.py b/wcsutil/hstwcs.py index 1c52f24..62b8e48 100644 --- a/wcsutil/hstwcs.py +++ b/wcsutil/hstwcs.py @@ -16,33 +16,35 @@ from mappings import basic_wcs __docformat__ = 'restructuredtext' -__version__ = '0.4' +__version__ = '0.7' + class HSTWCS(WCS): - """ - Purpose - ======= - Create a WCS object based on the instrument. - It has all basic WCS kw as attributes (set by pywcs). - It also uses the primary and extension header to define - instrument specific attributes. - """ + def __init__(self, fobj='DEFAULT', ext=None, minerr=0.0, wcskey=" "): """ - :Parameters: - `fobj`: string or PyFITS HDUList object or None + Create a WCS object based on the instrument. + + In addition to basic WCS keywords this class provides + instrument specific information needed in distortion computation. + + Parameters + ---------- + fobj: string or PyFITS HDUList object or None a file name, e.g j9irw4b1q_flt.fits a fully qualified filename[EXTNAME,EXTNUM], e.g. j9irw4b1q_flt.fits[sci,1] a pyfits file object, e.g pyfits.open('j9irw4b1q_flt.fits'), in which case the - user is responsible for closing the file object. - `ext`: int or None + user is responsible for closing the file object. + ext: int or None extension number if ext==None, it is assumed the data is in the primary hdu - - `minerr`: float + minerr: float minimum value a distortion correction must have in order to be applied. If CPERRja, CQERRja are smaller than minerr, the corersponding distortion is not applied. + wcskey: str + A one character A-Z or " " used to retrieve and define an + alternate WCS description. """ self.inst_kw = ins_spec_kw @@ -50,7 +52,7 @@ class HSTWCS(WCS): self.wcskey = wcskey if fobj != 'DEFAULT': - filename, hdr0, ehdr, phdu = self.parseInput(f=fobj, ext=ext) + filename, hdr0, ehdr, phdu = self._parseInput(f=fobj, ext=ext) self.filename = filename self.instrument = hdr0['INSTRUME'] @@ -76,7 +78,7 @@ class HSTWCS(WCS): self.setPscale() self.setOrient() - def parseInput(self, f=None, ext=None): + def _parseInput(self, f=None, ext=None): if isinstance(f, str): # create an HSTWCS object from a filename @@ -126,8 +128,20 @@ class HSTWCS(WCS): self.__setattr__(c, header.get(c, None)) def setInstrSpecKw(self, prim_hdr=None, ext_hdr=None): - # Based on the instrument kw creates an instalnce of an instrument WCS class - # and sets attributes from instrument specific kw + """ + Populate the instrument specific attributes: + + These can be in different headers but each instrument class has knowledge + of where to look for them. + + Parameters + ---------- + prim_hdr: pyfits.Header + primary header + ext_hdr: pyfits.Header + extension header + + """ if self.instrument in inst_mappings.keys(): inst_kl = inst_mappings[self.instrument] inst_kl = instruments.__dict__[inst_kl] @@ -148,50 +162,38 @@ class HSTWCS(WCS): raise KeyError, "Unsupported instrument - %s" %self.instrument def setPscale(self): - # Calculates the plate scale from the cd matrix - + """ + Calculates the plate scale from the CD matrix + """ cd11 = self.wcs.cd[0][0] cd21 = self.wcs.cd[1][0] self.pscale = np.sqrt(np.power(cd11,2)+np.power(cd21,2)) * 3600. def setOrient(self): - # Recompute ORIENTAT + """ + Computes ORIENTAT from the CD matrix + """ cd12 = self.wcs.cd[0][1] cd22 = self.wcs.cd[1][1] self.orientat = RADTODEG(np.arctan2(cd12,cd22)) - def updatePscale(self, pscale): - """Given a plate scale, update the CD matrix""" - old_pscale = self.pscale - self.pscale = pscale - self.wcs.cd = self.wcs.cd * pscale/old_pscale - self.naxis1 = self.naxis1 * old_pscale/ pscale - self.naxis2 = self.naxis2 * old_pscale/ pscale - self.wcs.crpix = self.wcs.crpix *old_pscale/pscale - - def updateOrient(self, orient): - """Given n angle update the CD matrix""" - if self.orientat == orient: - return - old_orient = self.orientat - self.orientat = orient - angle = fileutil.DEGTORAD(orient) - cd11 = -np.cos(angle) - cd12 = np.sin(angle) - cd21 = cd12 - cd22 = -cd11 - cdmat = np.array([[cd11, cd12],[cd21,cd22]]) - self.wcs.cd = cdmat * self.pscale/3600 - self.wcs.set() - - def readModel(self, update=False, header=None): """ Reads distortion model from IDCTAB. + If IDCTAB is not found ('N/A', "", or not found on disk), then - if SIP coefficients and first order IDCTAb coefficients are present + if SIP coefficients and first order IDCTAB coefficients are present in the header, restore the idcmodel from the header. If not - assign None to self.idcmodel. + + Parameters + ---------- + header: pyfits.Header + fits extension header + update: boolean (False) + if True - record the following IDCTAB quantities as header keywords: + CX10, CX11, CY10, CY11, IDCSCALE, IDCTHETA, IDCXREF, IDCYREF, + IDCV2REF, IDCV3REF """ if self.idctab == None or self.idctab == ' ': @@ -208,7 +210,7 @@ class HSTWCS(WCS): print 'Distortion model is not available: IDCTAB file %s not found\n' % self.idctab self.idcmodel = None else: - self._readModelFromIDCTAB(header=header, update=update) + self.readModelFromIDCTAB(header=header, update=update) def _readModelFromHeader(self, header): # Recreate idc model from SIP coefficients and header kw @@ -232,14 +234,19 @@ class HSTWCS(WCS): self.idcmodel = model - def _readModelFromIDCTAB(self, header=None, update=False): + def readModelFromIDCTAB(self, header=None, update=False): """ - Purpose - ======= Read distortion model from idc table. - Save some of the information as kw needed for interpreting the distortion - If header is provided and update is True, some IDC model kw - will be recorded in the header. + + Parameters + ---------- + header: pyfits.Header + fits extension header + update: boolean (False) + if True - save teh following as header keywords: + CX10, CX11, CY10, CY11, IDCSCALE, IDCTHETA, IDCXREF, IDCYREF, + IDCV2REF, IDCV3REF + """ if self.date_obs == None: print 'date_obs not available\n' @@ -263,8 +270,15 @@ class HSTWCS(WCS): def wcs2header(self, sip2hdr=False): """ - Create a pyfits.Header object from all WCS keywords, - including the SIP coefficients. + Create a pyfits.Header object from WCS keywords. + + If the original header had a CD matrix, return a CD matrix, + otherwise return a PC matrix. + + Parameters + ---------- + sip2hdr: boolean + If True - include SIP coefficients """ h = self.to_header() if self.wcs.has_cd(): @@ -332,6 +346,9 @@ class HSTWCS(WCS): ext_hdr.update('IDCV3REF', self.idcmodel.refpix['V3REF']) def printwcs(self): + """ + Print the basic WCS keywords. + """ print 'WCS Keywords\n' print 'CD_11 CD_12: %r %r' % (self.wcs.cd[0,0], self.wcs.cd[0,1]) print 'CD_21 CD_22: %r %r' % (self.wcs.cd[1,0], self.wcs.cd[1,1]) |