source: inundation/pyvolution/ermapper_grids.py @ 1804

Last change on this file since 1804 was 1804, checked in by tdhu, 19 years ago

Fixed syntax error in modified pyvolution/ermapper_grids.py

File size: 3.9 KB
Line 
1#!/usr/bin/env python
2
3# from os import open, write, read
4import Numeric
5
6
7def write_ermapper_header(ofile, datum = 'AGD66', projection = 'GEOGRAPHIC',
8                          coordinate_type = 'LL', rotation = '0:0:0.0',
9                          cell_type = 'IEEE4ByteReal', null_value = '-99999',
10                          x_dim = '100', x_ll = '0:0:0', y_dim = '100', y_ll = '0:0:0',
11                          num_lines = '3', num_cells = '4', num_bands = '1',
12                          band_id = 'band1'):
13
14    # Determine if the dataset is in lats/longs or eastings/northings and set header parameters
15    # accordingly
16    if coordinate_type is 'LL':
17        X_Class = 'Longitude'
18        Y_Class = 'Latitude'
19    elif coordinate_type is 'EN':
20        X_Class = 'Eastings'
21        Y_Class = 'Northings'
22
23    # open the header file for writing to
24    fid = open(ofile,'wt')
25
26    # Begin writing the header
27    fid.write('DatasetHeader Begin\n')
28    fid.write('\tVersion\t\t\t= "6.4"\n')
29    fid.write('\tDatasetType\t\t= ERStorage\n')
30    fid.write('\tDataType\t\t= Raster\n')
31    fid.write('\tByteOrder\t\t= LSBFirst\n')
32
33    # Write the coordinate space information
34    fid.write('\tCoordinateSpace Begin\n')
35    fid.write('\t\tDatum\t\t\t = "' + datum + '"\n')
36    fid.write('\t\tProjection\t\t = "' + projection + '"\n')
37    fid.write('\t\tCoordinateType\t = ' + coordinate_type + '\n')
38    fid.write('\t\tRotation\t\t = ' + rotation + '\n')
39    fid.write('\tCoordinateSpace End\n')
40
41    # Write the raster information
42    fid.write('\tRasterInfo Begin\n')
43    fid.write('\t\tCellType\t\t\t = ' + cell_type + '\n')
44    fid.write('\t\tNullCellValue\t\t = ' + null_value + '\n')
45    fid.write('\t\tRegistrationCellX\t\t = 0\n')
46    fid.write('\t\tRegistrationCellY\t\t = ' + str(int(num_lines) - 1) +'\n')
47    # Write the cellsize information
48    fid.write('\t\tCellInfo Begin\n')
49    fid.write('\t\t\tXDimension\t\t\t = ' + x_dim + '\n')
50    fid.write('\t\t\tYDimension\t\t\t = ' + y_dim + '\n')
51    fid.write('\t\tCellInfo End\n')
52    # Continue with wrting the raster information
53    fid.write('\t\tNrOfLines\t\t\t = ' + num_lines + '\n')
54    fid.write('\t\tNrOfCellsPerLine\t = ' + num_cells + '\n')
55    # Write the registration coordinate information
56    fid.write('\t\tRegistrationCoord Begin\n')
57    fid.write('\t\t\t' + X_Class + '\t\t\t = ' + x_ll + '\n')
58    fid.write('\t\t\t' + Y_Class + '\t\t\t = ' + y_ll + '\n')
59    fid.write('\t\tRegistrationCoord End\n')
60    # Continue with wrting the raster information
61    fid.write('\t\tNrOfBands\t\t\t = ' + num_bands + '\n')
62    fid.write('\t\tBandID Begin\n')
63    fid.write('\t\t\tValue\t\t\t\t = "' + band_id + '"\n')
64    fid.write('\t\tBandID End\n')
65    fid.write('\tRasterInfo End\n')
66    fid.write('DatasetHeader End\n')
67   
68    fid.close
69                         
70
71def write_ermapper_data(grid, ofile, data_format = Numeric.Float32):
72    # Convert the array to data_format (default format is Float32)
73    grid_as_float = grid.astype(data_format)
74
75    # Convert array to a string for writing to output file
76    output_string = grid_as_float.tostring()
77
78    # open output file in a binary format and write the output string
79    fid = open(ofile,'wb')
80    fid.write(output_string)
81    fid.close()
82
83
84def read_ermapper_data(ifile, data_format = Numeric.Float32):
85    # open input file in a binary format and read the input string
86    fid = open(ifile,'rb')
87    input_string = fid.read()
88    fid.close()
89
90    # convert input string to required format (Note default format is Numeric.Float32)
91    grid_as_float = Numeric.fromstring(input_string,data_format)
92    return grid_as_float
93
94def create_default_header(header):
95    pass
96    # fill any blanks in a header dictionary with default values
97    # input parameters:
98    # header:   a dictionary containing fields that are not meant
99    #           to be filled with default values
100
101   
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