Programmer Guide/Command Reference/EVAL/vsubc

vsubc

Conditional extraction of elements from the vector x.

Usage:

vsubc(x1,c,s1,x2)

vsubc(x1,c,s1,s2,x2)

Parameters:

x1

The input vector.

c

The condition. The following values are supported:

0 - select all x[i] where x[i] < s1

1 - select all x[i] where x[i] > s1

2 - select all x[i] where s1 < x[i] < s2

s1

A real number. See c for details.

s2

A real number (only used if c==2). See c for details.

x2

x2 is optional. If specified, the elements in x2 are extracted based on the selected values in x1. x2 must be a vector with exactly the same number of rows as x1.

Result:

The result is a scalar or a vector with the selected elements from x1 (or x2 - see x2 for details).

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 with nrow(x) columns and n rows, consisting of the rows o to o+n-1 of the argument x.

Description

The 2nd argument c (a number in the range 0..3) defines the condition used for the selection of the source rows.

• 2nd argument is 0: select all rows i of the source vector where x[i] < vmin

See also

vsubn, select,

vv

Example:

#a := eval vv(1,2,3,4,5)
#b := eval vmcol($#a, vv(5,4,3,2,1))
#c := vsubn($#a,3)
// -> vector: $#c = { 4 , 5 }
#d := eval vsubn($#b, 1 , 3)
// -> matrix: $#d[*,0] = { 2 , 3 , 4 },  $#d[*,1] = { 4 , 3 , 2 }
#e := eval vsubn($#a, 2, 1)
// -> scalar: $#e = 2, this is equivalent to $#a[2]
#f := eval vsubn($#b, 2, 1)
// -> vector (!!): $#f = { 3 , 3 }, this is equivalent to $#b[2,*]

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