File Methods

The oap library contains a couple of Python functions to save optical-arrays permanently or convert them to PNGs. There are also some helper functions to simplify the work with a great number of files.



array_as_oap_file

>>> oap.array_as_oap_file(array, filename, p_type=oap.UNDEFINED,
...                       file_extension=".oap")
Description:
Stores an optical-array with associated particle type as a binary file (oap-file).
Parameters:
array : string, list or numpy-array (1d or 2d | dtype=int)
The optical-array (particle image).
filename : string
File path without file extension.
p_type : char, optional
Particle Type of the cloud particle (default is b’u’).
file_extension : string, optional
Determines the file extension (default is “.oap”).

Examples:
>>> oap.array_as_oap_file(array, filename="particles/column01",
...                       p_type=oap.COLUMN)


array_as_png

>>> oap.array_as_png(array, filename=None, scale=1, slice_size=64)
Description:
Creates a PNG image of an optical-array. If the file name is not equal to None, the image is saved. Otherwise, the image is saved in random access memory only.
Parameters:
array : string, list or numpy-array (1d or 2d | dtype=int)
The optical-array (particle image).
filename : string, optional
File path without file extension.
scale : integeer, optional
The image scale (default is 1).
slice_size : integer, optional
The width of the optical-array (number of diodes). Only necessary, if the optical-array is one dimensional (default is 64).
Returns:
png image : PIL.Image.Image
A PIL image object that is stored in memory.

Examples:
>>> png_image = oap.array_as_png(array, filename="imgages/column01", scale=3)
>>> png_image
<PIL.Image.Image image mode=L size=192x21 at 0x27A37DA7988>


filepaths

>>> oap.filepaths(directory, exclude=None, include=None,
...               p_types=None, file_extension=OAP_FILE_EXTENSION)
Description:
Finds all files with the specified file extension in a directory and returns a list of file paths. It is possible to search only specific folders, or exclude folders from the search.
Parameters:
directory : string
The directory to be searched.
exclude : list of strings, optional
A list of folders to be excluded (default is None).
include : list of strings, optional
A list of specific subfolders to be searched exclusively (default is None).
p_types : list of chars

A list of the particle types you are looking for (default is None).

  • This should only be used if the searched files are oap-files!
file_extension : string, optional
The wanted file extension (default is “.oap”)
Returns:
A list of file paths.

Examples:
>>> files = oap.filepaths("tests", include=["data"])
['tests\\data\\array01.oap', 'tests\\data\\array02.oap', 'tests\\data\\array03.oap', 'tests\\data\\array04.oap']


read_particle_type

>>> oap.read_particle_type(filename)
Description:
Reads and returns the particle type of an oap file.
Parameters:
filename : string
File path with file extension.
Returns:
particle type : char

Examples:
>>> p_type = oap.read_particle_type("particles/column01.oap")
>>> p_type
b'c'
>>> p_type == oap.COLUMN
True


read_oap_file

>>> oap.read_oap_file(filename, as_type="array2d", slice_size=64)
Description:
Loads a binary oap-file and returns the optical-array and the corresponding stored particle type.
Parameters:
array : string, list or numpy-array (1d or 2d | dtype=int)
The optical-array (particle image).
filename : string
File path with file extension.
as_type : string, optional

The type of the returned optical-array - string, list or numpy-array (1d or 2d | dtype=int).

  • Possible values: None, “str”, “string”, “list”, “array”, “array2d”
slice_size : integer, optional
The width of the optical-array (default is 64).
Returns:
optical-array, particle type : tuple
The optical-array and the corresponding particle type.

Examples:
>>> array, p_type = oap.read_oap_file("particles/column01.oap")
>>> p_type
b'c'
>>> p_type == oap.COLUMN
True
>>> oap.print_array(array)
          1 1
      1 1 1 2 2 1
    1 2 3 2 3 3 2 2 2 2 3 2 2 1 1
    1 2 3 3 3 3 2 2 2 2 3 2 2 2 2 1 1 2 1 1 1
    2 3 3 3 3 3 2 3 3 2 3 3 3 3 3 2 2 3 2 2 2 2 2 2 2   1
    2 3 3 3 3 3 2 3 3 3 3 3 3 3 3 3 2 3 2 3 3 2 2 2 3 1 1
      1 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 2 2 2
          2 2 1 2 2 2 3 3 2 3 3 3 3 3 3 3 3 3 3 3 2 3 3 2
                      1 1   1 2 2 3 2 3 3 3 3 3 3 2 3 3 2
                            1 1 2 1 2 2 3 3 3 3 3 2 3 2 1
                                              1 1 1 1