~ubuntu-branches/ubuntu/utopic/liblas/utopic

  >>> from liblas import file
  >>> file.File('notafile.las') #doctest: +IGNORE_EXCEPTION_DETAIL
  Traceback (most recent call last):
  ...
  OSError: missing file
  
  >>> f = file.File('../test/data/TO_core_last_clip.las')
  
  >>> f.header # doctest: +ELLIPSIS
  <liblas.header.Header object at ...>
  
  >>> f.header.point_records_count
  8L
  
  >>> h = f.header
  >>> h.data_offset
  229L
  >>> p = f.read(0)
  >>> p.x, p.y, p.z
  (630262.30000000005, 4834500.0, 51.530000000000001)
  
  >>> p = f.read(6)
  >>> p.x, p.y, p.z
  (630320.95999999996, 4834500.0, 55.009999999999998)
  
  >>> f.seek(5)
  True

  >>> for i in f:
  ...   p = i
  ...   break

  >>> p.x, p.y, p.z
  (630323.57000000007, 4834500.0, 55.020000000000003)
  
  >>> f.seek(4)
  True

  >>> for i in f:
  ...   p = i
  ...   break

  >>> p.x, p.y, p.z
  (630327.58999999997, 4834500.0, 54.730000000000004)

  >>> f.seek(1)
  True

  >>> for i in f:
  ...   p = i
  ...   break

  >>> p.x, p.y, p.z
  (630282.45000000007, 4834500.0, 51.630000000000003)
  
  >>> f.close()
  >>> f.open()


Test Reading different locations and proper internal overwriting of the file

  >>> f2 = file.File('../test/data/TO_core_last_clip.las')
  >>> f2.header.data_offset
  229L  
  >>> p2 = f2.read(6)
  >>> p2.x, p2.y, p2.z
  (630320.95999999996, 4834500.0, 55.009999999999998)

  >>> p2 == f2.read(3)
  False
  >>> p2.x == f2.read(6).x
  True


  >>> f2.close()
  >>> del f2
  
  >>> points = []
  >>> for i in f:
  ...   points.append(i)
  ...   print i # doctest: +ELLIPSIS
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>

  >>> f[0]
  <liblas.point.Point object at ...>

  >>> out = f[0:3]
  >>> out
  [<liblas.point.Point object at ...>, <liblas.point.Point object at ...>, <liblas.point.Point object at ...>]
  >>> len(out)
  3

  >>> len(points)
  8

  >>> for p in points:
  ...   print p.x, p.y
  630262.3 4834500.0
  630282.45 4834500.0
  630300.08 4834500.0
  630346.83 4834500.0
  630327.59 4834500.0
  630323.57 4834500.0
  630320.96 4834500.0
  630280.89 4834500.0

  >>> points = []
  >>> f.seek(0)
  True  
  >>> for i in f:
  ...   points.append(i)
  ...   print i # doctest: +ELLIPSIS
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>


  >>> len(points)
  8  

  >>> del f
  
  >>> f = file.File('junk.las', mode="w", header=h)
  >>> f.header.data_offset
  229L    
  >>> sum(h.offset)
  0.0
  >>> h.min
  [630262.30000000005, 4834500.0, 50.899999999999999]

  >>> for i in points:
  ...    f.write(i)
  
  >>> pts = file.File('junk.las')
  Traceback (most recent call last):
  ...
  LASException: File junk.las is already open for write.  Close the file or delete the reference to it
  
  >>> f.close()
  >>> f.header

  >>> del f
  
Go read the new header we've written.  It might be out of date because what 
was written in mode='w' might not equal what was passed in as the header= paramete

  >>> f2 = file.File('junk.las')
  >>> h = f2.header
  >>> h.data_offset
  229L    
  >>> f2.close()
  
  >>> f = file.File('junk.las', mode='w+', header=h)
  
  >>> for i in points:
  ...    f.write(i)
  
  >>> f.close()
  
  >>> f = file.File('junk.las')
  >>> cnt = 0
  >>> for i in f:
  ...     cnt += 1
  
  >>> cnt
  16

  >>> buffered_header = f.header
  >>> del f 

  >>> buffered_header.padding = 1024 - buffered_header.data_offset
  >>> buffered_header.padding
  795L

  >>> buffered_header.data_offset
  229L

  >>> f3 = file.File('junk2.las',mode='w',header=buffered_header)

  >>> for i in points:
  ...    f3.write(i)
    
  >>> f3.close()

  >>> del f3

  >>> f4 = file.File('junk2.las')

  >>> f4.header.data_offset
  1024L
  >>> del f4

  
  >>> f = file.File('junk2.las')
  >>> f.header.data_offset
  1024L
  
  >>> points = []
  >>> for i in f:
  ...   points.append(i)
  ...   print i # doctest: +ELLIPSIS
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>

  >>> for g in points:
  ...   print round(g.x, 6)
  630262.3
  630282.45
  630300.08
  630346.83
  630327.59
  630323.57
  630320.96
  630280.89

Now try writing a 1.2 version of the junk2.las file above to ensure that
the data_offset *doesn't* change at all

  >>> buffered_header.data_offset = 1024
  >>> buffered_header.minor_version = 2
  >>> f3 = file.File('junk3.las',mode='w',header=buffered_header)

  >>> f3.header.data_offset
  1024L

  >>> for i in points:
  ...    f3.write(i)
    
  >>> f3.close()

  >>> del f3

  >>> f = file.File('junk3.las')
  >>> f.header.data_offset
  1024L
  
  >>> points = []
  >>> for i in f:
  ...   points.append(i)
  ...   print i # doctest: +ELLIPSIS
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>

  >>> for g in points:
  ...   print round(g.x, 6)
  630262.3
  630282.45
  630300.08
  630346.83
  630327.59
  630323.57
  630320.96
  630280.89


The header's offset will change +=2 if there isn't enough room in the 
header after you subtract the VLRs

  >>> from liblas import header
  >>> h2 = header.Header()
  >>> h2.data_offset = 227
  >>> h2.minor_version = 0
  >>> h2.scale = [0.01, 0.01, 0.01]
  >>> f4 = file.File('junk4.las',mode='w',header=h2)

  >>> f4.header.data_offset
  229L

  >>> for i in points:
  ...    f4.write(i)
    
  >>> f4.close()

  >>> del f4


  >>> f = file.File('junk4.las')
  >>> f.header.data_offset
  229L
  
  >>> points = []
  >>> for i in f:
  ...   points.append(i)
  ...   print i # doctest: +ELLIPSIS
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>
  <liblas.point.Point object at ...>

  >>> for g in points:
  ...   print round(g.x, 6)
  630262.3
  630282.45
  630300.08
  630346.83
  630327.59
  630323.57
  630320.96
  630280.89

  >>> comp_header = header.Header()
  >>> comp_header.minor_version = 2
  >>> comp_header.compressed = True
  >>> comp_header.scale = [0.01, 0.01, 0.01]  
  >>> compressed = file.File('output.laz', mode='w', header=comp_header)

  >>> comp_header.compressed
  True

  >>> for i in points:
  ...    compressed.write(i)
  
  >>> compressed.close()
  >>> del compressed

  >>> read_compressed = file.File('output.laz', mode='r')

  >>> read_compressed.header.compressed
  True

  >>> for i in read_compressed:
  ...   print round(i.x, 6)
  630262.3
  630282.45
  630300.08
  630346.83
  630327.59
  630323.57
  630320.96
  630280.89

  
  >>> read_compressed.close()
  >>> del read_compressed    

# The following tests writing out point data that are larger in size than 
# the base point format, allowing you to store extra data.  
# 
#   >>> f6 = file.File('../test/data/TO_core_last_clip.las')
#   >>> p2 = f6.read(6)
#   >>> p2.x, p2.y, p2.z
#   (630320.95999999996, 4834500.0, 55.009999999999998)
# 
#   >>> h6 = f6.header
#   >>> f = h6.schema
#   >>> f.time = True
#   >>> f.color = True
#   >>> f.size = 52
#   >>> h6.schema = f
#   >>> h6.data_record_length
#   52
# 
#   
# f.size - f.base_size will be 16 bytes of space (h6.data_record_length - 34 bytes for point format 3)
# 
# >>> import ctypes
#  
#   >>> d = (ctypes.c_ubyte * (f.size - f.base_size))() 
#   >>> d[10]
#   0
#   >>> d[0] = 13
# 
#   >>> d2 = (ctypes.c_ubyte * 6)() 
#   >>> d2[0] = 11
#     
#   >>> f7 = file.File('junk5.las',mode='w', header=h6)
#   >>> i = 0
#   >>> for p in points:
#   ...     if i == 0:
#   ...         p.data = d
#   ...     if i == 1:
#   ...         p.data = d2
#   ...     i = i + 1
#   ...     f7.write(p)
#   >>> f7.close()
#   >>> del f7
#   
#   >>> f8 = file.File('junk5.las')
#   >>> f8.header.data_record_length
#   52
# 
#   >>> p = f8[0].data[0]
#   >>> p
#   13
#   >>> p = f8[0].data[15]
#   >>> p
#   0
#   
#   >>> p = f8[1].data[0]
#   >>> p
#   11
  
  >>> import os
  >>> os.remove('junk.las')
  >>> os.remove('junk2.las')
  >>> os.remove('junk3.las')
  >>> os.remove('junk4.las')

#  >>> os.remove('junk5.las')
       
  >>> f = file.File('junk.las', mode="w", header=h)
  >>> import liblas.core
  >>> liblas.core.las.LASWriter_Destroy(f.handle)
  >>> print 'destroyed once'
  destroyed once
  >>> f.handle = None
  >>> liblas.core.las.LASWriter_Destroy(f.handle)
  Traceback (most recent call last):
  ...
  LASException: LASError in "LASWriter_Destroy": Pointer 'hWriter' is NULL in 'LASWriter_Destroy'.

  >>> import os
  >>> os.remove('junk.las')