Пример #1
0
    def fort_read(self,fmt,dtype=None):
        """Read a Fortran binary record.

        Inputs:

          fmt -- If dtype is not given this represents a struct.pack
                 format string to interpret the next record.  Otherwise this
                 argument is ignored.
          dtype -- If dtype is not None, then read in the next record as
                   an array of type dtype.

        Outputs: (data,)

          data -- If dtype is None, then data is a tuple containing the output
                  of struct.unpack on the next Fortan record.
                  If dtype is a datatype string, then the next record is
                  read in as a 1-D array of type datatype.
        """
        lookup_dict = {'ieee-le':"<",'ieee-be':">",'native':''}
        if dtype is None:
            fmt = lookup_dict[self.format] + fmt
            numbytes = struct.calcsize(fmt)
            nn = struct.calcsize("i");
            if (self.raw_read(nn) == ''):
                raise ValueError, "Unexpected end of file..."
            strdata = self.raw_read(numbytes)
            if strdata == '':
                raise ValueError, "Unexpected end of file..."
            data = struct.unpack(fmt,strdata)
            if (self.raw_read(nn) == ''):
                raise ValueError, "Unexpected end of file..."
            return data
        else:  # Ignore format string and read in next record as an array.
            fmt = lookup_dict[self.format] + "i"
            nn = struct.calcsize(fmt)
            nbytestr = self.raw_read(nn)
            if nbytestr == '':
                raise ValueError, "Unexpected end of file..."
            nbytes = struct.unpack(fmt,nbytestr)[0]
            howmany, dtype = getsize_type(dtype)
            ncount = nbytes / howmany
            if ncount*howmany != nbytes:
                self.rewind(4)
                raise ValueError, "A mismatch between the type requested and the data stored."
            if ncount < 0:
                raise ValueError, "Negative number of bytes to read:\n    file is probably not opened with correct endian-ness."
            if ncount == 0:
                raise ValueError, "End of file?  Zero-bytes to read."
            retval = numpyio.fread(self.file, ncount, dtype, dtype, self.bs)
            if len(retval) == 1:
                retval = retval[0]
            if (self.raw_read(nn) == ''):
                raise ValueError, "Unexpected end of file..."
            return retval
Пример #2
0
    def fort_read(self, fmt, dtype=None):
        """Read a Fortran binary record.

        Inputs:

          fmt -- If dtype is not given this represents a struct.pack
                 format string to interpret the next record.  Otherwise this
                 argument is ignored.
          dtype -- If dtype is not None, then read in the next record as
                   an array of type dtype.

        Outputs: (data,)

          data -- If dtype is None, then data is a tuple containing the output
                  of struct.unpack on the next Fortan record.
                  If dtype is a datatype string, then the next record is
                  read in as a 1-D array of type datatype.
        """
        lookup_dict = {'ieee-le': "<", 'ieee-be': ">", 'native': ''}
        if dtype is None:
            fmt = lookup_dict[self.format] + fmt
            numbytes = struct.calcsize(fmt)
            nn = struct.calcsize("i")
            if (self.raw_read(nn) == ''):
                raise ValueError, "Unexpected end of file..."
            strdata = self.raw_read(numbytes)
            if strdata == '':
                raise ValueError, "Unexpected end of file..."
            data = struct.unpack(fmt, strdata)
            if (self.raw_read(nn) == ''):
                raise ValueError, "Unexpected end of file..."
            return data
        else:  # Ignore format string and read in next record as an array.
            fmt = lookup_dict[self.format] + "i"
            nn = struct.calcsize(fmt)
            nbytestr = self.raw_read(nn)
            if nbytestr == '':
                raise ValueError, "Unexpected end of file..."
            nbytes = struct.unpack(fmt, nbytestr)[0]
            howmany, dtype = getsize_type(dtype)
            ncount = nbytes / howmany
            if ncount * howmany != nbytes:
                self.rewind(4)
                raise ValueError, "A mismatch between the type requested and the data stored."
            if ncount < 0:
                raise ValueError, "Negative number of bytes to read:\n    file is probably not opened with correct endian-ness."
            if ncount == 0:
                raise ValueError, "End of file?  Zero-bytes to read."
            retval = numpyio.fread(self.file, ncount, dtype, dtype, self.bs)
            if len(retval) == 1:
                retval = retval[0]
            if (self.raw_read(nn) == ''):
                raise ValueError, "Unexpected end of file..."
            return retval
Пример #3
0
    def read(self,count,stype,rtype=None,bs=None,c_is_b=0):
        """Read data from file and return it in a numpy array.

        Inputs:

          count -- an integer specifying the number of elements of type
                   stype to read or a tuple indicating the shape of
                   the output array.
          stype -- The data type of the stored data (see fwrite method).
          rtype -- The type of the output array.  Same as stype if None.
          bs -- Whether or not to byteswap (or use self.bs if None)
          c_is_b --- If non-zero then the count is an integer
                   specifying the total number of bytes to read
                   (must be a multiple of the size of stype).

        Outputs: (output,)

          output -- a numpy array of type rtype.
        """
        if bs is None:
            bs = self.bs
        else:
            bs = (bs == 1)
        howmany,stype = getsize_type(stype)
        shape = None
        if c_is_b:
            if count % howmany != 0:
                raise ValueError, "When c_is_b is non-zero then " \
                      "count is bytes\nand must be multiple of basic size."
            count = count / howmany
        elif type(count) in [types.TupleType, types.ListType]:
            shape = list(count)
            # allow -1 to specify unknown dimension size as in reshape
            minus_ones = shape.count(-1)
            if minus_ones == 0:
                count = product(shape,axis=0)
            elif minus_ones == 1:
                now = self.tell()
                self.seek(0,2)
                end = self.tell()
                self.seek(now)
                remaining_bytes = end - now
                know_dimensions_size = -product(count,axis=0) * getsize_type(stype)[0]
                unknown_dimension_size, illegal = divmod(remaining_bytes,
                                                         know_dimensions_size)
                if illegal:
                    raise ValueError("unknown dimension doesn't match filesize")
                shape[shape.index(-1)] = unknown_dimension_size
                count = product(shape,axis=0)
            else:
                raise ValueError(
                    "illegal count; can only specify one unknown dimension")
            shape = tuple(shape)
        if rtype is None:
            rtype = stype
        else:
            howmany,rtype = getsize_type(rtype)
        if count == 0:
            return zeros(0,rtype)
        retval = numpyio.fread(self.file, count, stype, rtype, bs)
        if shape is not None:
            retval = resize(retval, shape)
        return retval
Пример #4
0
from numpyio import fread, fwrite
from sys import argv

print "\nReading info from %s.hdr and" % argv[1]
print "%s.dat\n" % argv[1]
print "Writing %s.raw\n" % argv[1]

HEADERLEN = 640
BLOCKLEN = 49152

# Read the header file

file = open(argv[1]+'.hdr', 'r')
data = fread(file, HEADERLEN+8, 'b')
file.close()
header = data[4:-4]
infile = open(argv[1]+'.dat', 'r')
outfile = open(argv[1]+'.raw', 'w')

# Read and write the raw data

while (1):
    data = fread(infile, BLOCKLEN+8, 'b')
    if (len(data)==BLOCKLEN+8):
        fwrite(outfile, HEADERLEN, header, 'b')
        fwrite(outfile, BLOCKLEN, data[4:-4], 'b')
    else:
        break
print ''
infile.close()
outfile.close()
Пример #5
0
from __future__ import print_function
from numpyio import fread, fwrite
from sys import argv

print("\nReading info from %s.hdr and" % argv[1])
print("%s.dat\n" % argv[1])
print("Writing %s.raw\n" % argv[1])

HEADERLEN = 640
BLOCKLEN = 49152

# Read the header file

file = open(argv[1] + '.hdr', 'r')
data = fread(file, HEADERLEN + 8, 'b')
file.close()
header = data[4:-4]
infile = open(argv[1] + '.dat', 'r')
outfile = open(argv[1] + '.raw', 'w')

# Read and write the raw data

while (1):
    data = fread(infile, BLOCKLEN + 8, 'b')
    if (len(data) == BLOCKLEN + 8):
        fwrite(outfile, HEADERLEN, header, 'b')
        fwrite(outfile, BLOCKLEN, data[4:-4], 'b')
    else:
        break
print('')
infile.close()
Пример #6
0
    def read(self, count, stype, rtype=None, bs=None, c_is_b=0):
        """Read data from file and return it in a numpy array.

        Inputs:

          count -- an integer specifying the number of elements of type
                   stype to read or a tuple indicating the shape of
                   the output array.
          stype -- The data type of the stored data (see fwrite method).
          rtype -- The type of the output array.  Same as stype if None.
          bs -- Whether or not to byteswap (or use self.bs if None)
          c_is_b --- If non-zero then the count is an integer
                   specifying the total number of bytes to read
                   (must be a multiple of the size of stype).

        Outputs: (output,)

          output -- a numpy array of type rtype.
        """
        if bs is None:
            bs = self.bs
        else:
            bs = (bs == 1)
        howmany, stype = getsize_type(stype)
        shape = None
        if c_is_b:
            if count % howmany != 0:
                raise ValueError, "When c_is_b is non-zero then " \
                      "count is bytes\nand must be multiple of basic size."
            count = count / howmany
        elif type(count) in [types.TupleType, types.ListType]:
            shape = list(count)
            # allow -1 to specify unknown dimension size as in reshape
            minus_ones = shape.count(-1)
            if minus_ones == 0:
                count = product(shape, axis=0)
            elif minus_ones == 1:
                now = self.tell()
                self.seek(0, 2)
                end = self.tell()
                self.seek(now)
                remaining_bytes = end - now
                know_dimensions_size = -product(
                    count, axis=0) * getsize_type(stype)[0]
                unknown_dimension_size, illegal = divmod(
                    remaining_bytes, know_dimensions_size)
                if illegal:
                    raise ValueError(
                        "unknown dimension doesn't match filesize")
                shape[shape.index(-1)] = unknown_dimension_size
                count = product(shape, axis=0)
            else:
                raise ValueError(
                    "illegal count; can only specify one unknown dimension")
            shape = tuple(shape)
        if rtype is None:
            rtype = stype
        else:
            howmany, rtype = getsize_type(rtype)
        if count == 0:
            return zeros(0, rtype)
        retval = numpyio.fread(self.file, count, stype, rtype, bs)
        if shape is not None:
            retval = resize(retval, shape)
        return retval