def _rdhd(self, name):
"""Provide read access to header items via low-level calls."""
itype = itemtable[name]
if itype == '?': return self._rdhd_special(name)
h = self.haccess(name, 'read')
rv = []
if len(itype) == 1:
if itype == 'a': offset = 0
else:
t, offset = _miriad.hread_init(h)
assert(itype == t)
while True:
try: c, o = _miriad.hread(h, offset, itype)
except(IOError): break
if itype == 'a': c = c[:o]
rv.append(c)
offset += o
if itype == 'a': rv = ''.join(rv)
else:
t, offset = _miriad.hread_init(h); assert(t == 'b')
for t in itype:
v, o = _miread.hread(h, offset, t)
rv.append(v); offset += o
_miriad.hdaccess(h)
if len(rv) == 1: return rv[0]
elif type(rv) == str: return rv
else: return np.array(rv)
def _rdhd(self, name):
"""Provide read access to header items via low-level calls."""
itype = itemtable[name]
if itype == '?': return self._rdhd_special(name)
h = self.haccess(name, 'read')
rv = []
if len(itype) == 1:
if itype == 'a': offset = 0
else:
t, offset = _miriad.hread_init(h)
assert(itype == t)
while True:
try: c, o = _miriad.hread(h, offset, itype)
except(IOError): break
if itype == 'a': c = c[:o]
rv.append(c)
offset += o
if itype == 'a': rv = ''.join(rv)
else:
t, offset = _miriad.hread_init(h); assert(t == 'b')
for t in itype:
v, o = _miread.hread(h, offset, t)
rv.append(v); offset += o
_miriad.hdaccess(h)
if len(rv) == 1: return rv[0]
elif type(rv) == str: return rv
else: return n.array(rv)
def _rdhd_special(self, name):
"""Provide read access to special header items of type '?' to _rdhd"""
if name == 'freqs':
h = self.haccess(name, 'read')
c, o = _miriad.hread(h, 0, 'i')
rv = [c]; offset = 8
while True:
try:
c, o = _miriad.hread(h, offset, 'i')
rv.append(c); offset += 8
c, o = _miriad.hread(h, offset, 'd')
rv.append(c); offset += 8
c, o = _miriad.hread(h, offset, 'd')
rv.append(c); offset += 8
except(IOError): break
_miriad.hdaccess(h)
return rv
else: raise ValueError('Unknown special header: ' + name)
def _rdhd_special(self, name):
"""Provide read access to special header items of type '?' to _rdhd"""
if name == 'freqs':
h = self.haccess(name, 'read')
c, o = _miriad.hread(h, 0, 'i')
rv = [c]; offset = 8
while True:
try:
c, o = _miriad.hread(h, offset, 'i')
rv.append(c); offset += 8
c, o = _miriad.hread(h, offset, 'd')
rv.append(c); offset += 8
c, o = _miriad.hread(h, offset, 'd')
rv.append(c); offset += 8
except(IOError): break
_miriad.hdaccess(h)
return rv
else: raise ValueError('Unknown special header: ' + name)
