Position

Position(expr, patt)

returns the list of positions for which expr matches patt.

Position(expr, patt, ls)

returns the positions on levels specified by level specification ls.

Examples

>> Position({1, 2, 2, 1, 2, 3, 2}, 2)
{{2},{3},{5},{7}}

Find positions upto 3 levels deep

>> Position({1 + Sin(x), x, (Tan(x) - y)^2}, x, 3)
{{1,2,1},{2}}

Find all powers of x

>> Position({1 + x^2, x y ^ 2,  4 y,  x ^ z}, x^_)
{{1,2},{4}}

Use Position as an operator

>> Position(_Integer)({1.5, 2, 2.5})
{{2}}

Implementation status

• ✅ - full supported

Github

• Implementation of Position