Programmer Guide/Command Reference/EVAL/vsubc: Difference between revisions
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{{DISPLAYTITLE:{{SUBPAGENAME}}}} | {{DISPLAYTITLE:{{SUBPAGENAME}}}} | ||
Extract rows from a vector or matrix. | Extract rows from a vector or matrix. | ||
;Usage: | ;Usage: | ||
:{|class="keinrahmen" | |||
|<code>vsubc(<var>x</var>, <var>c</var>, <var>v</var> {, <var>y</var>})</code> ||with ''c'' = 0, 1, 4 or 5 | |||
|- | |||
|<code>vsubc(<var>x</var>, <var>c</var>, <var>v</var><sub>1</sub>, <var>v</var><sub>2</sub> {, <var>y</var>})</code>|| with ''c'' = 2, 3, 6 or 7 | |||
|} | |||
:;<var>x</var>: condition vector (and source vector if argument ''y'' is not supplied); must be a vector! | :;<var>x</var>: condition vector (and source vector if argument ''y'' is not supplied); must be a vector! | ||
:;<var>c</var>: condition used to select values | |||
:;<var>v, v<sub>1</sub>, v<sub>2</sub></var>: lower and/or upper boundary; must be a scalar or a vector with the same length as ''x'' | :;<var>v, v<sub>1</sub>, v<sub>2</sub></var>: lower and/or upper boundary; must be a scalar or a vector with the same length as ''x'' | ||
:;<var>y</var>: optional source data; must be a vector or matrix with the same number of rows as ''x'' | :;<var>y</var>: 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 ''' | ;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 ... | !value of ''c'' !!row ''i'' is selected if ... | ||
| Line 19: | Line 23: | ||
|'''3''' ||<code>''x''[i] < ''v''<sub>1</sub> or ''x''[''i''] > ''v''<sub>2</sub></code> | |'''3''' ||<code>''x''[i] < ''v''<sub>1</sub> or ''x''[''i''] > ''v''<sub>2</sub></code> | ||
|- | |- | ||
|'''4''' ||<code>''x''[''i''] | |'''4''' ||<code>''x''[''i''] ≤ ''v''</code> | ||
|- | |- | ||
|'''5''' ||<code>''x''[''i''] | |'''5''' ||<code>''x''[''i''] ≥ ''v''</code> | ||
|- | |- | ||
|'''6''' ||<code>''v''<sub>1</sub> | |'''6''' ||<code>''v''<sub>1</sub> ≤ '' ''x''[''i''] ≤ ''v''<sub>2</sub></code> | ||
|- | |- | ||
|'''7''' ||<code>''x''[i] | |'''7''' ||<code>''x''[i] ≤ ''v''<sub>1</sub> or ''x''[''i''] ≥ ''v''<sub>2</sub></code> | ||
|} | |} | ||
: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|vsubn]], [[../limit|limit, limitlow, limithigh]], [[../select|select]] | |||
[[../#Functions|<function list>]] | |||
Example: | Example: | ||
| Line 43: | Line 48: | ||
// -> vector: $#e = { 1 , 2 , 4 , 5 } | // -> vector: $#e = { 1 , 2 , 4 , 5 } | ||
</pre> | </pre> | ||
Latest revision as of 12:10, 21 April 2011
Extract rows from a vector or matrix.
- Usage
vsubc(x, c, v {, y})with c = 0, 1, 4 or 5 vsubc(x, c, v1, v2 {, y})with c = 2, 3, 6 or 7
- x
- condition vector (and source vector if argument y is not supplied); must be a vector!
- c
- condition used to select values
- v, v1, v2
- lower and/or upper boundary; must be a scalar or a vector with the same length as x
- y
- optional source data; must be a vector or matrix with the same number of rows as x
- Result
- A numerical object consisting of all selected rows of the source y (or x if y is not supplied). The 2nd argument c must be a number in the range 0 to 7 and defines the condition used for the selection of the source rows.
value of c row i is selected if ... 0 x[i] < v1 x[i] > v2 v1 < x[i] < v23 x[i] < v1 or x[i] > v24 x[i] ≤ v5 x[i] ≥ v6 v1 ≤ x[i] ≤ v27 x[i] ≤ v1 or x[i] ≥ v2
- If a boundary v is a vector, the i-th element of the vectors x and v are compared, otherwise the element x[i] is compared with the number v. The function failes, if no row is selected.
- See also
- vsubn, limit, limitlow, limithigh, select
Example:
#a := eval vv(1,2,3,4,5)
#b := eval vmcol($#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 }
