Yorick (programming language)

From HandWiki
Yorick
Designed byDavid H. Munro
First appeared1996; 28 years ago (1996)
Stable release
2.2.04 / May 2015; 8 years ago (2015-05)
OSUnix-like systems including macOS, Microsoft Windows
LicenseBSD
Filename extensions.i
Websitegithub.com/LLNL/yorick

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:

> 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]
Arbitrary elements
> 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]
Pseudo-index

Like "theading" in PDL and "broadcasting" in Numpy, Yorick has a mechanism to do this:

> 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
Rubber index

".." is a rubber-index to represent zero or more dimensions of the array.

> 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

"*" is a kind of rubber-index to reshape a slice(sub-array) of array to a vector.

> x(*)
[1,2,3,4,5,6]
Tensor multiplication

Tensor multiplication is done as follows in Yorick:

P(,+, )*Q(, +)

means [math]\displaystyle{ \sum_{j=1}^{j=N}{P_{ijkl}Q_{mnj}} }[/math]

> 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

External links