# Difference between revisions of "KeepIf Command"

From GeoGebra Manual

(removed betamanual template) |
(command syntax: changed [ ] into ( )) |
||

(6 intermediate revisions by 5 users not shown) | |||

Line 1: | Line 1: | ||

− | <noinclude>{{Manual Page|version= | + | <noinclude>{{Manual Page|version=5.0}}</noinclude>{{command|logical}} |

− | {{command|logical}} | + | ; KeepIf( <Condition>, <List> ): Creates a new list that only contains those elements of the initial list that fulfil the condition. |

− | ; KeepIf | + | : {{Example|1=<code>KeepIf(x<3, {1, 2, 3, 4, 1, 5, 6})</code> returns the new list ''{1, 2, 1}''.}} |

− | : {{Example|1=<code>KeepIf | ||

:{{note|1=For list of numbers arbitrary condition may be used. For list of other objects one can use only conditions of the form <code>x==constant</code> or <code>x!=constant</code>.}} | :{{note|1=For list of numbers arbitrary condition may be used. For list of other objects one can use only conditions of the form <code>x==constant</code> or <code>x!=constant</code>.}} | ||

− | ; KeepIf | + | ; KeepIf( <Condition>, <Variable>, <List> ) |

− | : This syntax allows a more flexible condition | + | : This syntax allows a more flexible condition. |

+ | : {{Example|1=For Points ''P, Q, R'' <code>KeepIf(x(A) < 3, A, {P, Q, R})</code> will filter the points whose ''x''-coordinate is less than ''3'' out of the list. The variable ''A'' is replaced in turn with ''P'' then ''Q'' then ''R'' for the check.}} |

## Latest revision as of 19:43, 30 September 2017

- KeepIf( <Condition>, <List> )
- Creates a new list that only contains those elements of the initial list that fulfil the condition.
**Example:**`KeepIf(x<3, {1, 2, 3, 4, 1, 5, 6})`

returns the new list*{1, 2, 1}*.

**Note:**For list of numbers arbitrary condition may be used. For list of other objects one can use only conditions of the form`x==constant`

or`x!=constant`

.

- KeepIf( <Condition>, <Variable>, <List> )
- This syntax allows a more flexible condition.
**Example:**For Points*P, Q, R*`KeepIf(x(A) < 3, A, {P, Q, R})`

will filter the points whose*x*-coordinate is less than*3*out of the list. The variable*A*is replaced in turn with*P*then*Q*then*R*for the check.