Editing Yorick (programming language)

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{{notability|date=July 2011}}
{{no footnotes|date=January 2018}}
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{{Infobox programming language
| name                   = Yorick
| logo                   = 
| caption                = 
| file_ext               = .i
| paradigm               = 
| year                   = {{Start date and age|1996}}
| designer               = [[David H. Munro]]
| developer              = 
| latest_release_version = 2.2.04
| latest_release_date    = {{Start date and age|2015|05}}
| latest_test_version    = 
| latest_test_date       = 
| typing                 = 
| implementations        = 
| dialects               = 
| influenced_by          = 
| influenced             =
| operating_system       = [[Unix-like]] systems including [[macOS]], [[Microsoft Windows]]
| license                = [[BSD licenses|BSD]]
| website                = {{URL|https://github.com/LLNL/yorick}}
}}

'''Yorick''' is an [[Interpreted language|interpreted]] [[programming language]] designed for [[numerics]], [[graph of a function|graph]] plotting, and steering large scientific simulation codes. It is quite fast due to [[Array data structure|array]] syntax, and extensible via [[C (programming language)|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 [[Perl Data Language|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 <math>\sum_{j=1}^{j=N}{P_{ijkl}Q_{mnj}}</math>

<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>

==External links==
*[http://www.linuxjournal.com/article/2184 Linux Journal Review]
*[https://web.archive.org/web/20170102091157/http://www.jeh-tech.com/yorick.html Yorick tutorial on JehTech]
{{Lawrence Livermore National Laboratory|state=autocollapse}}

{{DEFAULTSORT:Yorick (Programming Language)}}
[[Category:Array programming languages]]
[[Category:Free and open source interpreters]]
[[Category:Lawrence Livermore National Laboratory]]
[[Category:Programming languages created in 1996]]