Syntax

Snuggs wraps Numpy in expressions with the following syntax:

expression = "(" (operator | function) *arg ")"
arg = expression | name | number | string

Examples

import snuggs
snuggs.eval('(+ 1 2)')
# 3

snuggs.eval("(* 3.5 (asarray 1 1))")
# array([ 3.5,  3.5])

snuggs.eval("(+ (asarray 1 1) b)", b=np.array([2, 2]))
# array([3, 3])

ctx = OrderedDict((
    ('a', np.array([5, 5])),
    ('b', np.array([2, 2]))
))
snuggs.eval("(- (read 1) (read 2))", ctx)
# array([3, 3])

Functions and operators

Arithmetic (* + / -) and logical (< <= == != >= > & |) operators are available. Members of the numpy module such as asarray(), mean(), and where() are also available.

snuggs.eval("(mean (asarray 1 2 4))")
# 2.3333333333333335

snuggs.eval("(where (& tt tf) 1 0)",
    tt=numpy.array([True, True]),
    tf=numpy.array([True, False]))
# array([1, 0])

Higher-order functions

New in snuggs 1.1 are higher-order functions map and partial.

snuggs.eval("((partial * 2) 2)")
# 4

snuggs.eval('(asarray (map (partial * 2) (asarray 1 2 3)))')
# array([2, 4, 6])

Performance notes

Snuggs makes simple calculator programs possible. None of the optimizations of, e.g., numexpr (multithreading, elimination of temporary data, etc) are currently available.

If you’re looking to combine Numpy with a more complete Lisp, see Hy:

=> (import numpy)
=> (* 2 (.asarray numpy [1 2 3]))
array([2, 4, 6])