def __init__(self, fname): """ Initialise an NDF from a file. This slurps the whole thing in, including all extensions, axes etc. This could cause memory problems on large files. You can use either standard format NDF sections in such case or Pythonic ones. e.g. Given an NDF 'image' listed by hdstrace to have a data array DATA(3,4,5), the entire image can be specified using any of 'image', 'image(1:3,1:4,1:5)' or 'image[0:5,0:4,0:3]' where as usual with the index ranges in Python, the last index is NOT included and indices start at 0. While those used to dealing with NDFs may find the first with () more familiar, the second may be simpler if you deal with the outout from a python script since it is identically ordered and more consistent with taking sub-sections using Python as in ndf = starlink.ndf.Ndf('image') subim = image.data[0:5,0:4,0:3] The following attributes are created: data -- the data array, a numpy N-d array bound -- pixel limits of data array. 2xndim array of lower and upper bounds var -- variances, a numpy N-d array axes -- Axis components label -- label string title -- title string units -- data unit string head -- header/extensions, a dictionary """ object.__init__(self) # Next section changes from a pseudo-Pythonic version of an NDF section # to a Fortran-like one i.e. reverse the indices, add 1 to the first of a pair # or to the sole index reg = re.compile(r'([^\[\]]*)\[([^\[\]]*)\]') m = reg.match(fname) if m != None: tup = m.group(2).split(',') nname = m.group(1) + '(' for st in tup[-1:0:-1]: subt = st.split(':') if len(subt) == 1: add = str(int(subt[0])+1) elif len(subt) == 2: add = str(int(subt[0])+1) + ':' + str(int(subt[1])) else: raise Exception('Could not understand ' + fname) nname += add + ',' subt = tup[0].split(':') if len(subt) == 1: add = str(int(subt[0])+1) elif len(subt) == 2: add = str(int(subt[0])+1) + ':' + str(int(subt[1])) else: raise Exception('Could not understand ' + nname) nname += add + ')' fname = nname # OK, get on with NDF stuff ndf.init() ndf.begin() try: indf = ndf.open(fname) self.data = indf.read('Dat') self.bound = indf.bound() self.var = indf.read('Var') self.label = indf.cget('Label') self.title = indf.cget('Title') self.units = indf.cget('Units') # Read the axes self.axes = [] for nax in range(self.data.ndim): self.axes.append(Axis(indf, nax)) # Read the extensions self.head = {} nextn = indf.xnumb() for nex in range(nextn): xname = indf.xname(nex) loc1 = indf.xloc(xname, 'READ') hdsloc = hds._transfer(loc1) _read_hds(hdsloc, self.head) hdsloc.annul() ndf.end() except: ndf.end() raise
def tearDown(self): ndf.end() os.remove( self.testndf )