vsubc

Extract rows from a vector or matrix.

Usage

vsubc(x, c, v {, y }}) with c = 0, 1, 4 or 5

vsubc(x, c, v1, v2 {, y }}) with c = 2, 3, 6 or 7

x

condition vector (and source vector if argument y is not supplied); must be a vector!

v, v₁, v₂

lower and/or upper boundary; must be a scalar or a vector with the same length as x

y

optional source data; must be a vector or matrix with the same number of rows as x

Result

A numerical object consisting of all selected rows of the source y (or x if y is not supplied). The 2nd argument c must be a number in the range 0 to 7 and defines the condition used for the selection of the source rows.

value of c	row i is selected if ...
0	x[i] < v
1	x[i] > v
2	v1 < x[i] < v2
3	x[i] < v1 or x[i] > v2
4	x[i] <= v
5	x[i] >= v
6	v1 <= x[i] <= v2
7	x[i] <= v1 or x[i] >= v2

If a boundary v is a vector, the i-th element of the vectors x and v are compared, otherwise the element x[i] is compared with the number v. The function failes, if no row is selected.

See also

vsubn, select, vv

Example:

#a := eval vv(1,2,3,4,5)
#b := eval vmcol($#a, vv(5,4,3,2,1))
#c := vsubc($#a,0,3)
// -> vector: $#c = { 1 , 2 }
#d := eval vsubc($#a,2,0,5,$#b)
// -> matrix: $#d[*,0] = { 2 , 3 , 4 },  $#d[*,1] = { 4 , 3 , 2 }
#e := eval vsubc($#a,7,2,4)
// -> vector: $#e = { 1 , 2 , 4 , 5 }

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