Programmer Guide/Command Reference/EVAL/vsubn: Difference between revisions
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== | Extract rows from a vector or matrix. | ||
;Usage: '''<code><var>vsubn(x</var> {, <var>o</var> {, <var>n</var>}})</code>''' | |||
:;<var>x</var>: source vector or matrix | |||
:;<var>o</var>: offset, 0 <= ''o'' < <code>nrow(''x'')</code> | |||
:;<var>n</var>: length, ''n'' > 0 and ''o''+''n'' <= <code>nrow(''x'')</code> | |||
;Result: A matrix with <code>nrow(''x1'')</code> columns. The columns of the arguments are merged from left to right into the rows of the result matrix. Note: <code>vmrow(a,b,c)</code> returns the same result as <code>trn(vmcol(a,b,c))</code>, but <code>vmrow</code> is faster and uses less memory than the nested command. | |||
;See also: [[Programmer_Guide/Command_Reference/EVAL/vv|vv]], [[Programmer_Guide/Command_Reference/EVAL/vvset|vvget]], [[Programmer_Guide/Command_Reference/EVAL/vvset|vvset]], [[Programmer_Guide/Command_Reference/EVAL/vvcat|vvcat]], [[Programmer_Guide/Command_Reference/EVAL/vmcol|vmcol]], [[Programmer_Guide/Command_Reference/EVAL/vsubn|vsubn]], [[Programmer_Guide/Command_Reference/EVAL/vsubc|vsubc]] | |||
Example: | |||
<pre> | |||
#a := eval vv(1,2,3,4,5) | |||
#b := eval init(5,2,0) | |||
#c := eval vmcol($#a, $#b, $#a) | |||
// -> $#c is a matrix with 4 rows and 5 columns: | |||
// $#c[*,*] = $#a, #c[1,*] = $#b[*,0], $#c[2,*] = $#b[*,1], $#c[3,*] = $#a | |||
</pre> | |||
[[Programmer_Guide/Command_Reference/EVAL#Functions|<function list>]] | |||
Revision as of 08:55, 6 April 2011
Extract rows from a vector or matrix.
- Usage
vsubn(x {, o {, n}})- x
- source vector or matrix
- o
- offset, 0 <= o <
nrow(x) - n
- length, n > 0 and o+n <=
nrow(x)
- Result
- A matrix with
nrow(x1)columns. The columns of the arguments are merged from left to right into the rows of the result matrix. Note:vmrow(a,b,c)returns the same result astrn(vmcol(a,b,c)), butvmrowis faster and uses less memory than the nested command. - See also
- vv, vvget, vvset, vvcat, vmcol, vsubn, vsubc
Example:
#a := eval vv(1,2,3,4,5) #b := eval init(5,2,0) #c := eval vmcol($#a, $#b, $#a) // -> $#c is a matrix with 4 rows and 5 columns: // $#c[*,*] = $#a, #c[1,*] = $#b[*,0], $#c[2,*] = $#b[*,1], $#c[3,*] = $#a
