Template page for GeoGebra Builders Handbook
<<<<< Structure - Delete this section if you copy this template >>>>>
_______________________________________________________________________________________________________________ Text should have headlines to clarify and summarise the content - Please DO NOT CHANGE existing headlines. If necessary, add more sections or delete unused sections instead. If you copy this Template - then you would probably delete this section.
The headline for the entire page should clearly indicate what the tip, trick, techniche or magic is, but you are also encouraged to tweak the headline somewhat toward magic, technology or other cool stuff, such as "Remote Control - Moving independant points with other points" Constructions and videos should not exceed 700 px width. <<<<< Sections within five sets of angle brackets are just structural comments on this template and should be removed before publishing >>>>> ________________________________________________________________________________________________________________Introduction
<<<<< Typically, each page starts with a text which is intended as an introduction to the particular magic you wish to show off, in this case how to move two independent points by dragging just one of them. Explain in simple terms what the construction below shows and instruct the reader what to try. You can also put a link to your GeoGebra profile page here as indicated. >>>>>
These two points are created as independent points, but with scripting we can make them move as one object. We can even make one point move both while the other is independent. Try dragging either point in the construction below!
(This side originally created by Jonas Hall)
Sample construction
When to use
<<<<< Add a section on when it is suitable to use this tip, trick, technique or magic. >>>>>
This trick with two points may not be useful in itself, but variants of it can be extremely useful, such as these:
- Define a line through two points, A on the y-axis and B anywhere. Make sure that when you move A, then B moves with it so that the slope isn't changed. Moving B will not affect A and so only the slope is changed (This particular example should go on a page of it's own).
- "Grouping" objects so that one point acts as the anchor of the entire group
- <<<<< More examples of good use. >>>>>
How do you do this?
<<<<< Give brief but adequate instructions in text how to achieve this particular magic, clarifying the KEY ELEMENTS >>>>>
The construction above uses the following KEY ELEMENTS:
- Two points: Create two points, A and B.
- Scripts for each point: To make the two points move at the same time when either of them is moved you need to do a little scripting.
In the onUpdate script of point A, type:
SetValue[B , ( x(A)+1, y(A)+1 ) ]and In the onUpdate script of point B, type:SetValue[A , ( x(B)+1, y(B)+1 ) ]In this case the offset between the points is (1, 1) but this could obviously be generalized by using a variable (DO give more examples). To make A move both points while B is independent, just use the script for point A and leave point B unscripted.
[Code] button among the text tools available in the text sections. This will give a fixed character width. Also use bold text for the initial part of each KEY ELEMENT >>>>>
<<<<< Comments to Screencast - Delete this section >>>>>
<<<<< Typically, you also include a simple screencast where you make a construction using this trick. Don't make it too wide - 700 px is about the maximum to retain a good layout. Be focused and say what you want to say as you do it, explaining the ideas along the way (DO put central ideas in the text as well).
Videos should be uploaded to YouTube so that we can collect their links into a playlist later. Add the search tags geogebra, builders, handbook + any specific tags that relate like points, scripting etc. Make sure the video is public.
Alternatively, send the video to me and I will upload it - though really you should get a Youtube account if you haven't got one already. >>>>>
Screencast of construction
More examples
One point dragging both, but not the other way round: https://www.geogebra.org/m/UEFW7KBV
<<<<< Make real links but also leave address visible as I have shown, or even better: include constructions here. If example is really good but also uses other techniques, consider making it into it's own worksheet and sticking it in the "Magic Items" chapter for examples. >>>>>