Programmer Guide/Command Reference/EVAL/vsubc

Extract rows from a vector or matrix.

Usage

vsubc(x , 0 , vmin {, y }})

vsubc(x , 1 , vmax {, y }})

vsubc(x , 2 , vmin, vmax {, y }})

vsubc(x , 3 , vmin, vmax {, y }})

x

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

vmin

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

vmax

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 3 and defines the condition used for the selection of the source rows.

value of c	row i is selected if ...
0	x[i] < vmin

c=1

select all rows i where x[i] > vmax

c=2

select all rows i where vmin < x[i] < vmax

c=3

select all rows i where x[i] <= vmin or x[i] >= vmax

If a boundary vmin/vmax is a vector, the i-th element of the vectors x and vmin/vmax are compared, otherwise the element x[i] is compared with the number vmin/vmax. 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 }

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