util — General Utilities¶
The ale.util module
New in version 0.1.0:
- ale.util.JBFPvlParser(lines)¶
Janky But Faster PVL Parser(TM)
Only really supports ISIS’s Kernel DB files. This is because KernelDB files are sometimes very large for smithed kernels. This should bring the parsing time for those DB files from minutes to seconds. Still needs nested object/group support and it should be able to read most PVL files.
Parameters¶
- linesstr
string body of PVL file.
- ReturnsPVLModule
object representing the parsed PVL
- ale.util.create_spk_dependency_tree(kernels)¶
construct the dependency tree for the body states in a set of kernels.
Parameters¶
- kernelslist
The list of kernels to evaluate the dependencies in. If two kernels in this list contain the same information for the same pair of bodies, then the later kernel in the list will be identified in the kernel property for that edge in dep_tree.
Returns¶
- dep_treenx.DiGraph
The dependency tree for the kernels. Nodes are bodies. There is an edge from one node to another if the state of the body of the source node is defined relative to the state of the body of the destination node. The kernel edge property identifies what kernel the information for the edge is defined in.
- ale.util.duckpool(naifvar, start=0, length=10, default=None)¶
Duck typing friendly version of spiceypy kernel pool functions.
Parameters¶
- naifvarstr
naif var string to query pool for
- startint
Index of first value
- lengthint
max number of values returned
- defaultobj
Default value to return if key is not found in kernel pool
Returns¶
- : obj
Spice value returned from spiceypy if found, default value otherwise
- ale.util.find_kernels(cube, isis_data, format_as=<class 'dict'>)¶
Find all kernels for a cube and return a json object with categorized kernels.
Parameters¶
- cubestr
Path to an ISIS cube
- isis_datastr
path to $ISISDATA
- format_asobj
What type to return the kernels as, ISIS3-like dict/PVL or flat list
Returns¶
- : obj
Container with kernels
- ale.util.generate_kernels_from_cube(cube, expand=False, format_as='list')¶
Parses a cube label to obtain the kernels from the Kernels group.
Parameters¶
- cubecube
Path to the cube to pull the kernels from.
- expandbool, optional
Whether or not to expand variables within kernel paths based on your IsisPreferences file. See
get_isis_preferences()for how the IsisPreferences file is found.- format_asstr, optional {‘list’, ‘dict’}
How to return the kernels: either as a one-dimensional ordered list, or as a dictionary of kernel lists.
Returns¶
- : list
One-dimensional ordered list of all kernels from the Kernels group in the cube.
- : Dictionary
Dictionary of lists of kernels with the keys being the Keywords from the Kernels group of cube itself, and the values being the values associated with that Keyword in the cube.
- ale.util.get_ck_frames(kernel)¶
Get all of the reference frames defined in a kernel.
Parameters¶
- kernelstr
The path to the kernel
Returns¶
- idslist
The set of reference frames IDs defined in the kernel
- ale.util.get_isis_mission_translations(isis_data)¶
Use ISIS translation files and return a lookup table.
Parameters¶
- isis_datastr
path to $ISIS3DATA
Returns¶
- : dict
Dictionary mapping label mission strings to ISIS3 mission strings
- ale.util.get_isis_preferences(isis_preferences=None)¶
Returns ISIS Preference file as a pvl object.
This will search the following locations, in order, for an IsisPreferences file:
The .Isis directory in your home directory
The directory pointed to by the ISISROOT environment variable
- ale.util.get_metakernels(spice_dir=None, missions={}, years={}, versions={})¶
Given a root directory, get any subdirectory containing metakernels, assume spice directory structure.
Mostly doing filtering here, might be worth using Pandas?
Parameters¶
- spice_dirstr
Path containing Spice directories downloaded from NAIF’s website
- missionsset, str
Mission or set of missions to search for
- yearsset, str, int
year or set of years to search for
- versionsset, str
version or set of versions to search for
- ale.util.query_kernel_pool(matchstr='*', max_length=10)¶
Collect multiple keywords from the naif kernel pool based on a template string
Parameters¶
- matchstrstr
matchi_c formatted str
- max_lengthint
maximum length array to get from naif keywords
Returns¶
- : dict
python dictionary of naif keywords in {keyword:value} format.
- ale.util.read_pvl(path, use_jank=False)¶
Syntax sugar, used to load a pvl object file from path
Parameters¶
- pathstr
Path to Pvl file
- use_jankbool
If true, uses faster but less reliable JBFPvlParser, else uses standard PVL parser.
- ale.util.search_isis_db(dbobj, labelobj, isis_data)¶
Given an PVL obj of a KernelDB file and an Isis Label for a cube, find the best kernel to attach to the cube.
The Logic here is a bit gross, but it matches ISIS’s implementation very closely.
Parameters¶
- dbobjPVLModule
ISIS3 KernelDB file as a loaded PVLModule
- labelobjPVLModule
Cube label as loaded PVLModule
- isis_datastr
path to $ISISDATA
Returns¶
- : dict
dictionary containing kernel list and optionally the kernel type if relevant.
- ale.util.spkmerge_config_string(dep_tree, output_spk, bodies, lsk, start, stop)¶
Create the contents of an spkmerge config file that will produce a spk that completely defines the state of a list of bodies for a time range.
Parameters¶
- dep_treenx.DiGraph
Dependency tree from create_kernel_dependency_tree that contains information about what the state of different bodies are relative to and where that information is stored.
- output_spkstr
The path to the SPK that will be output by spkmerge
- bodieslist
The list of body ID codes that need to be defined in the kernel created by spkmerge
- lskstr
The absolute path to the leap second kernel to use
- startstr
The UTC start time for the kernel created by spkmerge
- stopstr
The UTC stop time for the kernel created by spkmerge
Returns¶
- : str
The contents of an spkmerge config file that will produce a kernel that defines the state of the input bodies for the input time range.