format = one of bzip2, gzip, zip, or zlib

This option allows a compression format to be specified explicitly. Options are bzip2, gzip, zip, or zlib. The default is zlib.

The Compress(A) command takes the given byte array or list and compresses it into a lossless, more compact format. The return value is a ByteArray.

If A is a list, its contents must be integers between -128 and 127.

$\mathrm{OmegaArray}≔\mathrm{Array}\left(1..{10}^5\,\mathrm{NumberTheory}:-\mathrm{NumberOfPrimeFactors}\,\mathrm{datatype}=\mathrm{integer}\left[1\right]\right)$

$\mathrm{CompressedOmegaArray}≔\mathrm{ArrayTools}:-\mathrm{Compress}\left(\mathrm{OmegaArray}\right)$

$\mathrm{numelems}\left(\mathrm{OmegaArray}\right),\mathrm{numelems}\left(\mathrm{CompressedOmegaArray}\right)$

$100000,37013$

$\mathrm{data}≔\mathrm{Statistics}:-\mathrm{Sample}\left(\mathrm{DiscreteUniform}\left(-10\,10\right)\,1000000\right)$

$\mathrm{original}≔\mathrm{convert}\left(\mathrm{data}\,\mathrm{ByteArray}\right)$

$\mathrm{compressed}≔\mathrm{ArrayTools}:-\mathrm{Compress}\left(\mathrm{original}\right)$

$1.-\frac{\mathrm{numelems}\left(\mathrm{compressed}\right)}{\mathrm{numelems}\left(\mathrm{original}\right)}$

$0.8718235000$

$\mathrm{PaulCliffordText}≔''It\; was\; a\; dark\; and\; stormy\; night;\; the\; rain\; fell\; in\; torrents\; -\; except\; at\; occasional\; intervals,\; when\; it\; was\; checked\; by\; a\; violent\; gust\; of\; wind\; which\; swept\; up\; the\; streets\; (for\; it\; is\; in\; London\; that\; our\; scene\; lies),\; rattling\; along\; the\; housetops,\; and\; fiercely\; agitating\; the\; scanty\; flame\; of\; the\; lamps\; that\; struggled\; against\; the\; darkness.''\:$

$\mathrm{original}≔\mathrm{StringTools}:-\mathrm{ToByteArray}\left(\mathrm{PaulCliffordText}\right)$

$\mathrm{compressed}≔\mathrm{ArrayTools}:-\mathrm{Compress}\left(\mathrm{original}\,\mathrm{format}=\mathrm{gzip}\right)$

$1.-\frac{\mathrm{numelems}\left(\mathrm{compressed}\right)}{\mathrm{numelems}\left(\mathrm{original}\right)}$

$0.2996941896$

The ArrayTools[Compress] command was introduced in Maple 2015.

For more information on Maple 2015 changes, see Updates in Maple 2015.

The ArrayTools[Compress] command was updated in Maple 2018.

The format option was updated in Maple 2018.