Algosim documentation: indices

indices

Finds the indicies of a value in an ordered container.

Syntax

Description

If X is an ordered container and x any value, then indices(X, x) returns the list containing the the 1-based indices of the occurrences of x in X.

index(X, x, ε) has the same behaviour, but it compares floating-point values with epsilon ε if ε > 0; if ε = 0, a default, non-zero, epsilon is used.

Examples

Alice ≔ ExampleData("Alice in Wonderland");
indices(words(Alice) @ LowerCase, "music")
14243
19926
19968

indices(words(Alice) @ LowerCase, "song")
11998
14430
21051
21398
22177
22180
22362

A ≔ SequenceVector(10) ⊗ SequenceVector(10)
⎛  1    2    3    4    5    6    7    8    9   10⎞
⎜  2    4    6    8   10   12   14   16   18   20⎟
⎜  3    6    9   12   15   18   21   24   27   30⎟
⎜  4    8   12   16   20   24   28   32   36   40⎟
⎜  5   10   15   20   25   30   35   40   45   50⎟
⎜  6   12   18   24   30   36   42   48   54   60⎟
⎜  7   14   21   28   35   42   49   56   63   70⎟
⎜  8   16   24   32   40   48   56   64   72   80⎟
⎜  9   18   27   36   45   54   63   72   81   90⎟
⎝ 10   20   30   40   50   60   70   80   90  100⎠

indices(A, 50)
(5, 10)
(10, 5)

See also