Difference between revisions of "LocusEquation Command"
From GeoGebra Manual
(added link to Zoltan's GeoGebraBook about this cmd) |
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:*The calculation is done using [[w:Gröbner_basis|Gröbner bases]], so sometimes extra branches of the curve will appear that were not in the original locus.}} | :*The calculation is done using [[w:Gröbner_basis|Gröbner bases]], so sometimes extra branches of the curve will appear that were not in the original locus.}} | ||
− | {{betamanual|version=5. | + | {{betamanual|version=5.2|1= |
{{Note|1= | {{Note|1= | ||
− | In GeoGebra 5 and above a remote web server may be used to perform the calculation (this can be disabled by using command line option <code><nowiki>--singularWS=enable:false</nowiki></code>).}}}} | + | In GeoGebra 5.2 and above a remote web server may be used to perform the calculation (this can be disabled by using command line option <code><nowiki>--singularWS=enable:false</nowiki></code>).}}}} |
{{Notes|1=<div> | {{Notes|1=<div> | ||
*Further informations and examples on [http://www.geogebra.org/student/b121563# GeoGebra] | *Further informations and examples on [http://www.geogebra.org/student/b121563# GeoGebra] | ||
*See also [[Locus Command|Locus]] command.</div>}} | *See also [[Locus Command|Locus]] command.</div>}} |
Revision as of 10:02, 30 July 2015
- LocusEquation[ <Locus> ]
- Calculates the equation of a Locus and plots this as an Implicit Curve.
- Note: The Locus must be made from a Point (not from a Slider)
- LocusEquation[ <Point Creating Locus Line Q>, <Point P> ]
- Calculates the equation of a Locus by using inputs tracer point Q and mover point P, and plots this as an Implicit Curve.
- Example:Let us construct a parabola as a locus: Create free Points A and B, and Line d lying through them (this will be the directrix of the parabola). Create free point F for the focus. Now create P on Line d (the mover point), then create line p as a perpendicular line to d through P. Also create line b as perpendicular bisector of Line Segment FP. Finally, point Q (the point creating locus line) is to be created as intersection of Lines p and b. Now
LocusEquation[Q,P]
will find and plot the exact equation of the locus.
- Notes:
- Works only for a restricted set of geometric loci, i.e. using points, lines, circles, conics. [Rays and line segments will be treated as (infinite) lines]
- If the locus is too complicated then it will return 'undefined'.
- The calculation is done using Gröbner bases, so sometimes extra branches of the curve will appear that were not in the original locus.
Following text is about a feature that is supported only in GeoGebra 5.2.
Note: In GeoGebra 5.2 and above a remote web server may be used to perform the calculation (this can be disabled by using command line option --singularWS=enable:false ). |