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-indexLike "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 multiplicationTensor multiplication is done as follows in Yorick:
P(,+, )*Q(, +)means ∑ j = 1 j = N P i j k l Q m n j {\displaystyle \sum _{j=1}^{j=N}{P_{ijkl}Q_{mnj}}}
> 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]]