Open source cross-platform software of geometry, analysis and simulation - Yves Biton
 
Home - Constructions

Presentation of constructions

publication Sunday 30 January 2011.


MathGraph32 constructions offer the user the ability to incorporate in a figure very sophisticated elements in an easy way.

To use a construction, you simple have to choose the sources elements and the construction will complete the figure, incorporating elements (intermediary or final). Some of these elements will be invisible (intermediary objects) end the others (final objects) wile be available to create other objects.

Since 3.3.0 version of MathGraph32, predefined constructions are available and directly usable via menu item Constructions - implement predefined construction.

These constructions are classified in differents folders.

For more information on predefined constructions see this page.

You can also create your own constructions and gather them in a special folder of your disk.

This folder location is specified via menu item Options - Preferences - Constructions directory. Use the Browse button to choose the folder of your choice.

To create an owner defined construction, you must first create a figure, use menu items Constructions - Sources objects choice to choose graphical and numerical sources objects.

Then you have to choose final elements (graphical or numerical) via menu item Constructions - Final objects choice. You can choose for final objects only elements exclusively created with sources objects.

Once sources and final objects indicated, use menu item Constructions - Finish current construction. You are asked to give a name to the construction. Choose a meaning name. It is also very useful to fill the info edit box named info. This info will explain how the construction works.

At the end of the info edit box, you may enter informations that will appear when the user will choose the sources objects.

For instance, if your constructions needs two sources objects, a numerical value (radius of a circle to be created by the construction) and a point (that will be the center), enter at the bottom of the info edit box the following lines :

#1:the circle radius

#2:the circle center

Once the construction finished, it is a part of the figure and will be saved to disk with the figure is saved to a file, but it is better to save the construction in a seperate mgc file via menu item Constructions - Save construction of figure to file. It is better to keep the same name for the file and then construction. This mgc file will be available when you choose the menu item Construction - Impement construction from file.

To be noticed:

When a construction is used, numerical objects are always chosen first.

Frames are considered as numerical obejcts.

When a construction is implemented in a figure, intermediary objects created by the construction are not available for creating other objects, but are visible in the protocol display (F5 key) if the checkbox Trace through constructions is selected.

Intermediary objects may be merged in the figure. They will then become usual objects. For this, use menu item Constructions - Merge constructions implemented in figure. This will be useful if you want to modify an already defined construction.

Graphical sources objects

Graphical sources objects of a construction can be objects of the following types : free point, linked point, line, half-line, segment, circle, arc of circle, polygone, broken line.

You must be careful for the choice of sources objects when you create a construction.

If a free point is chosen as source object when creating a construction, when this construction will be implemented, a some point can be chosen (including a free point).

On the contrary, if a linked point has been chosen for source object in a creation of construction, when this construction will be implemented, you will have to choose a linked point.

Numerical sources objects

Numerical sources objects may belong to the following types : real or complex calculus, function of one, two or three variables (real or complex), recurrent sequence (real or complex) and variable.

You must be careful for the choice of numerical sources objects when you create a construction.

If a real calculus has been chosen for source object when creating a construction, when this construction will be implemented, a some real value can be chosen, for example an angle measure or a variable.

On the contrary, if a variable has been chosen for a source object when creating a construction, when this contruction will be implemented, you will have to specify a variable.

Advanced topics

- If you want a free point to become a final object, you must first select this point as a source object then choose it as a final graphical object. A pop-up message will warn you that this free point is no longer a final object and is no longer considered as a source object.

- If you want a variable to become a final object, you must first select this variable as a source object then choose it as a final numerical object. A pop-up message will warn you that this variable is no longer a final object and is no longer considered as a source object.