user_guide:tutorials:tarballs

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user_guide:tutorials:tarballs [2019/02/11 16:45] – ↷ Page moved from user_guide:howto:tarballs to user_guide:tutorials:tarballs oroehriguser_guide:tutorials:tarballs [2019/02/11 16:45] (current) – restored. oroehrig
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-====== Saving and Restoring an Array of Polytopes ====== +{{page>.:latest:@FILEID@}}
- +
-If you want to deal with a whole family of polytopes at the same time, it will sometimes be convenient to save and restore them to a single file. polymake has a simple mechanism for this, storing your array of polytopes into a single tarball. +
- +
-The necessary functions for this are contained in the script "tarballs" that you can load into your polymake session by calling +
-<code> +
-polytope > script("tarballs"); +
-</code> +
-It provides the two functions ''pack_tarball'' and ''unpack_tarball''.  +
- +
-===== Storing ===== +
- +
-Here is a simple example, where we create an array @a containing a cube and a simplex and save this to a file. +
-<code> +
-polytope > @a = (); +
-polytope > $a[0] = cube(3); +
-polytope > $a[1] = simplex(3); +
-polytope > pack_tarball("simple_polytopes.tgz",@a); +
-</code> +
-This creates a file ''simple_polytopes.tgz'' in the current directory that is a tarred (and gzipped) archive containing two polymake files. polymake detects whether you want the archive gzipped or not from the supplied file extension (''*.tar.gz'' or ''*.tgz''). You can verify this by calling ''tar tvfz simple_polytopes.tgz'' from the command line: +
- +
-<code> +
-[nightingale]:~/temp>tar tvfz simple_polytopes.tgz  +
--rw------- xxx/yyy 1468 2009-07-01 17:20 1.poly +
--rw------- xxx/yyy  854 2009-07-01 17:20 2.poly +
-[nightingale]:~/temp> +
-</code> +
- +
-If you want to get more descriptive names for your polymake files then you have to set a name for each polytope first. +
- +
-<code> +
-polytope > $a[0]->name = "my_cube"; +
-polytope > $a[1]->name = "my_simplex"; +
-polytope > pack_tarball("simple_polytopes.tgz",@a); +
-</code> +
- +
-sets the names of the files in the tarball to ''my_cube.poly'' and ''my_simplex.poly'': +
-<code> +
-[nightingale]:~/temp>tar tvfz simple_polytopes.tgz  +
--rw------- xxx/yyy  952 2009-07-01 17:21 my_cube.poly +
--rw------- xxx/yyy  650 2009-07-01 17:21 my_simplex.poly +
-[nightingale]:~/temp> +
-</code> +
- +
-===== Restoring the array ===== +
- +
-You can restore your saved array by using the function ''unpack_tarball'': +
- +
-<code> +
-polytope > @a=unpack_tarball("simple_polytopes.tgz"); +
-polytope > print $a[0]->name; +
-my_cube +
-</code> +
- +
-If you just want a specific polytope from your tarball, then you can supply its name in the command: +
-<code> +
-polytope > @a=unpack_tarball("simple_polytopes.tgz","my_simplex.poly"); +
-polytope > print $a[0]->name; +
-my_simplex +
-</code> +
- +
-You may supply more than one filename. However, wildcards are not supported. Note that changes in the files are not automatically stored in the archive, you have to call ''pack_tarball'' to update the files.  +
- +
-===== Packing archives outside polymake ===== +
- +
-You can of course apply ''tar'' to your favorite family of polymake files to create a tarball without using polymake. It can be read by polymake as long as the files are at the root of the archive (i.e. don't pack a whole directory tree). The archive also may not contain non-polymake files. +
  
  • user_guide/tutorials/tarballs.txt
  • Last modified: 2019/02/11 16:45
  • by oroehrig