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|
>>> from liblas import vlr
>>> v = vlr.VLR()
>>> v.reserved
43707
>>> v.recordid
0
>>> v.recordid = 2
>>> v.recordid
2
>>> str(v.userid.decode())
''
>>> v.userid = b'liblas.org'
>>> str(v.userid.decode())
'liblas.org'
>>> str(v.description.decode())
''
>>> v.description = b'libLAS'
>>> str(v.description.decode())
'libLAS'
>>> v.recordlength = 256
>>> v.recordlength
256
>>> import ctypes
>>> data = (ctypes.c_ubyte * 256)()
>>> data[10]
0
>>> for i in range(256):
... data[i] = 2+i
>>> data[10]
12
>>> v.data = data
# Ensure we can round trip the data
>>> [data[i] for i in range(10)]
[2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
>>> [v.data[i] for i in range(10)]
[2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
# Ensure poking one array doesn't affect the other
>>> data[1] = 32
>>> v.data = data
>>> data[1] = 3
>>> v.data[1]
32
>>> data[1]
3
>>> [v.data[i] for i in range(10)]
[2, 32, 4, 5, 6, 7, 8, 9, 10, 11]
>>> import liblas
# >>> liblas.HAVE_GDAL
# >>> liblas.HAVE_LIBGEOTIFF
>>> from liblas import file
>>> f = file.File('../test/data/srs.las')
>>> h = f.header
>>> int(h.records_count)
3
>>> def test_srs():
... s = h.srs
... if not liblas.HAVE_LIBGEOTIFF:
... return True
... if not liblas.HAVE_GDAL:
... return s.proj4 == '+proj=utm +zone=17 +ellps=WGS84 +units=m '
... if liblas.HAVE_GDAL:
... return s.proj4 == '+proj=utm +zone=17 +datum=WGS84 +units=m +no_defs '
... return False
>>> test_srs()
True
>>> v = h.GetVLR(0)
>>> v.recordid
34735
>>> str(v.userid.decode())
'LASF_Projection'
>>> data = v.data
>>> len(data)
72
>>> data[6]
8
# Deleting a VLR shouldn't change the offset
>>> int(h.data_offset)
759
>>> h.DeleteVLR(0)
>>> int(h.data_offset)
759
>>> del f
>>> f = file.File('../test/data/srs.las')
>>> h = f.header
>>> int(f.header.data_offset)
759
>>> f2 = file.File('junk_srs.las',mode='w',header=h)
>>> for p in f:
... f2.write(p)
>>> f2.close()
>>> del f2
>>> f3 = file.File('junk_srs.las')
>>> int(f3.header.records_count)
3
>>> int(f3.header.data_offset)
759
>>> import os
>>> os.remove('junk_srs.las')
|
