Yorick (programming language)
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| Designed by | David H. Munro |
|---|---|
| First appeared | 1996 |
| Stable release | 2.2.04
/ May 2015 |
| OS | Unix-like systems including macOS, Microsoft Windows |
| License | BSD |
| Filename extensions | .i |
| Website | github |
Yorick is an interpreted programming language designed for numerics, graph plotting, and steering large scientific simulation codes. It is quite fast due to array syntax, and extensible via C or Fortran routines. It was created in 1996 by David H. Munro of Lawrence Livermore National Laboratory.
Features
Indexing
Yorick is good at manipulating elements in N-dimensional arrays conveniently with its powerful syntax.
Several elements can be accessed all at once:
<syntaxhighlight lang="rout"> > x=[1,2,3,4,5,6]; > x [1,2,3,4,5,6] > x(3:6) [3,4,5,6] > x(3:6:2) [3,5] > x(6:3:-2) [6,4] </syntaxhighlight>
- Arbitrary elements
<syntaxhighlight lang="rout"> > x=[[1,2,3],[4,5,6]] > x [[1,2,3],[4,5,6]] > x([2,1],[1,2]) [[2,1],[5,4]] > list=where(1<x) > list [2,3,4,5,6] > y=x(list) > y [2,3,4,5,6] </syntaxhighlight>
- Pseudo-index
Like "theading" in PDL and "broadcasting" in Numpy, Yorick has a mechanism to do this:
<syntaxhighlight lang="rout"> > x=[1,2,3] > x [1,2,3] > y=[[1,2,3],[4,5,6]] > y [[1,2,3],[4,5,6]] > y(-,) [[[1],[2],[3]],[[4],[5],[6]]] > x(-,) [[1],[2],[3]] > x(,-) 1,2,3 > x(,-)/y [[1,1,1],[0,0,0]] > y=[[1.,2,3],[4,5,6]] > x(,-)/y [[1,1,1],[0.25,0.4,0.5]] </syntaxhighlight>
- Rubber index
".." is a rubber-index to represent zero or more dimensions of the array.
<syntaxhighlight lang="rout"> > x=[[1,2,3],[4,5,6]] > x [[1,2,3],[4,5,6]] > x(..,1) [1,2,3] > x(1,..) [1,4] > x(2,..,2) 5 </syntaxhighlight>
"*" is a kind of rubber-index to reshape a slice(sub-array) of array to a vector.
<syntaxhighlight lang="rout"> > x(*) [1,2,3,4,5,6] </syntaxhighlight>
- Tensor multiplication
Tensor multiplication is done as follows in Yorick:
P(,+, )*Q(, +)
means
<syntaxhighlight lang="rout"> > x=[[1,2,3],[4,5,6]] > x [[1,2,3],[4,5,6]] > y=[[7,8],[9,10],[11,12]] > x(,+)*y(+,) [[39,54,69],[49,68,87],[59,82,105]] > x(+,)*y(,+) [[58,139],[64,154]] </syntaxhighlight>