toasty cascade
¶
The cascade
operation computes lower-resolution tiles from higher-resolution
tiles. The same algorithms apply to either studies or all-sky TOAST pyramids.
Usage¶
toasty cascade
[--parallelism FACTOR]
[--format FORMAT]
{--start DEPTH}
PYRAMID-DIR
The PYRAMID-DIR
argument gives the location of a directory containing tile
pyramid data files. The --start DEPTH
argument gives the depth at which
tiles already exist. For instance, with --start 5
, the pyramid should
contain level-5 tiles, and the cascade will fill in tiles between levels 4 and
0, inclusive.
Each tile pyramid directory may contain multiple data formats (e.g. PNG, FITS). The --type
argument specifies which one the cascade operation should apply to. Valid choices
are png
, jpg
, npy
, and fits
. The default is to try and determine the
format automatically.
The --parallelism FACTOR
argument specifies the level of parallism to use.
On operating systems that support parallel processing, the default is to use
all CPUs. To disable parallel processing, explicitly specify a factor of 1.
Notes¶
Currently, parallel processing is only supported on the Linux operating system,
because fork()
-based multiprocessing is required. MacOS should support this,
but there is currently (as of Python 3.8) a bug preventing that.