Definition
Let Σ be an alphabet, # a symbol not in Σ.
Let x1x2... x|x|, y1y2... y|y|, z1z2... z|z|, ... be n words (i.e. finite sequences) of elements of Σ. Let denote the length of the longest word, i.e. the maximum of |x|, |y|, |z|, ... .
The convolution of these words is a finite sequence of n-tuples of elements of (Σ ∪ {#}), i.e. an element of :
- ,
where for any index i > |w|, the wi is #.
The convolution of x, y, z, ... is denoted conv( x, y, z, ...), zip( x, y, z, ...) or x ⋆ y ⋆ z ⋆ ...
The inverse to convolution is sometimes denoted unzip.
A variation of the convolution operation is defined by:
where is the minimum length of the input words. It avoids the use of an adjoined element, but destroys information about elements of the input sequences beyond .
Read more about this topic: Convolution (computer Science)
Famous quotes containing the word definition:
“No man, not even a doctor, ever gives any other definition of what a nurse should be than this—”devoted and obedient.” This definition would do just as well for a porter. It might even do for a horse. It would not do for a policeman.”
—Florence Nightingale (1820–1910)
“One definition of man is “an intelligence served by organs.””
—Ralph Waldo Emerson (1803–1882)
“The definition of good prose is proper words in their proper places; of good verse, the most proper words in their proper places. The propriety is in either case relative. The words in prose ought to express the intended meaning, and no more; if they attract attention to themselves, it is, in general, a fault.”
—Samuel Taylor Coleridge (1772–1834)