Education 0.2

Dr. Geo for IPad demo

Hilaire Fernandes — Saturday, January 28 2012

Dr. Geo: hacker spirit in a candy box

Hilaire Fernandes — Thursday, December 15 2011

When you teach mathematics at secondary schools, you enjoy using interactive geometry software with your students. Dr.Geo is one such free software, it comes with some unique features. With such software, students learn geometry the way it should be learned -- by drawing, but Dr. Geo goes one step further.

Dr. Geo has a long tradition on GNU/Linux. It was the first software of this category since 1999. Beginning 2006, it plays nicely on Windows and Mac OSX as well.

In fact Dr. Geo bundle is now distributed as an universal portable application. This means student Bob can use the software on his usb key on the school's Mac OSX, then continue working on an Internet coffee's GNU/Linux workstation, then finish his work at home on his Windows PC. Each time, the same portable app is used. Moreover, when suddenly interrupted, Bob can save the session of his work - like a memory dump - to continue later, on a different workstation or system.

This is true both for interactive geometry activities and programmed geometry sketches. The later feature is a nice extension, an API, to design programmed geometry sketch. Of course the resulting sketches are all interactive. Read this small example. Programming is also available in interactive sketch, the user can plug small scripts in the canvas to do specific computation, for example to compute a curve and a tangent line at an arbitrary position.

Therefore, advanced teachers/students will appreciate the fact that scripting is more like writing math formulas than writing low level programs (no need to do a lot of initialization, for example). To draw an interactive segment and a bissector, you write:

drgeo := DrGeoCanvas new.
s1 := drgeo segment: 0@0 to: 5@5.
drgeo perpendicular: s1 at: (drgeo middleOf: s1).

Last but not least, free software spirit is so much at the heart of Dr. Geo -- you can study, modify and distribute its source code from itself.

Yes! You can modify Dr. Geo from Dr. Geo!

All in all, Dr. Geo is a hacker spirit in a candy box: young learners enjoy using it, when they grow up they can dig in programming and even learn from the Dr. Geo own design.

All pure fun.

Enseignement informatique classe de terminale

Hilaire Fernandes — Friday, November 25 2011

L'informatique de nouveau à l'honneur dans l'Éducation Nationale, voici le programme officiel.

C'est un beau programme d'enseignement type des années 80, lorsque la programmation objet commençait alors à percer dans l'industrie, mais pas encore dans l'éducation. Dans ce programme, le terme objet apparaît deux fois, et encore pas dans le sens de programmation objet.

La programmation objet fût pensée comme une abstraction puissante du réelle, pour gérer sa complexité et d'en faciliter sa modélisation. C'est donc dommage que ce programme commence par la vision des écrous et des boulons, au lieu de commencer par un niveau d'abstraction supérieur de type engrenage et autres roues dentées.

On n'apprend jamais assez de nos ainés. Dans les années 70, Alan Kay a travaillé avec de très brillantes personnes pour définir Smalltalk comme un langage de programmation accessible aux enfants. Élever intellectuellement les enfants, c'est le dada d'Alan, et il y a dédié une très grande partie de sa carrière (couronnée par un prix Turing en 2005) . Comme il voulait que cela soit vraiment aisé pour les élèves, il a repris les paradigmes de souris, fenêtre, affichage graphique, menu, etc. comme éléments d'un environnement pour un langage qui était lui même purement objet et réflexif, pour justement donner une vision d'ensemble, d'augmentation intellectuelle comme le définissait Engelbart (inventeur de la souris), et permettre aux enfants de produire des programmes vraiment intéressants et motivants pour eux. Lorsque Steve Jobs vit toutes ses idées géniales lors d'une visite à l'équipe d'Alan, il conçu dans les mois qui suivirent le Macintosh... Grand seigneur, il débaucha également Alan.

Dr. Geo suit également cette vision, écrit en Smalltalk, il s'utilise comme Cabri Géomètre tout en proposant une approche programmation de géométrie euclidienne par son interface objet. Encore une abstraction confortable du domaine géométrique pour les élèves. Il n'est donc pas surprenant non plus que Scratch soit lui même écrit en Smalltalk, nous sommes toujours dans cette vision, et on peut poursuivre avec l'environnement graphique de programmation et modélisation Etoys, déployé sur quelques millions de d'ordinateurs portables XO pour enfants, lui aussi encore écrit avec Smalltalk.

Ces puissants outils reposent sur un paradigme, la programmation orientée objet, grande absente de ce programme d'enseignement.

3D Cube section

Hilaire Fernandes — Friday, November 18 2011

You can produce pseudo 3D figure. A friend sent me this example: the section of a cube by a plane.

In this sketch, the author plays with the transparency of several overlapping polygons to emphasis the 3D perception.

English video tutorial

Hilaire Fernandes — Saturday, November 12 2011

Video tutorials are funs for three reasons:

it is efficient for the user both in term of relevance and time to get to the point
it is easy to produce and not time consuming for the producer
it is easy to distribute through the video server. DailyMotion even supports upload and conversion from Ogg/Theora video!

For theses reasons I am producing DrGeo video tutorials with English spoken comments, be nice with me, English is not my native language.

Visit DrGeo group@Dailymotion

DrGeo lock and text item

Hilaire Fernandes — Sunday, November 6 2011

We now have a text item to print multiple lines of text.

Also free items like free point, free point on curve, value, script and text have a new flag to lock them when dragging items in the canvas. This feature is very useful.

Should be due in the upcoming 11.12 release.

Conic Sections

Hilaire Fernandes — Saturday, November 5 2011

Alain Busser presents us a nice tutorial to build conic sections with Dr. Geo. He also proposes a macro-construction of this resulting work.

Read his tutorial

DrGeoII pre-release 11.12b

Hilaire Fernandes — Wednesday, November 2 2011

A few changes based on user requests:

circle can be constructed by center and segment
added back the intersection tool. You have now two options to construct intersection:
- as before, on the fly, when constructing a line, you can construct the intersection
- by selecting two lines, you need to access the new intersection tool in the Point menu or toolbar.

The changes are in pre-release 11.12b.

From your latest DrGeo installation, you can upgrade to DrGeo pre-release 11.12b. To upgrate to latest release, select in the DrGeo environment menu "update DrGeo", then save the session to make the changes permanent.

Huge sketch

Hilaire Fernandes — Friday, October 28 2011

Xavi de Blas sent me this sketch to calculate a body gravity center. The file is huge and I will include it in the next Dr.Geo 11.12 release.

The resulting sketch:

The sketch with the hidden constructions:

Getting the property tool back

Hilaire Fernandes — Friday, October 28 2011

After an user request, I just added back in DrGeoII the item property tool.

With this tool you can edit:

the coordinates of a free point on the plane
the curvilinear abscissa of a point free on a curve, the abscissa belongs to [0 ; 1]
a free value
a script

In the later case, DrGeo opens a tiny Smalltalk browser to study and to modify the code. When modifying and saving the code, the canvas is automatically updated. Underneath, the script code is recompiled, thanks to the Smalltalk machinery.

All but the script operation are backed in the command machinery of DrGeo, so you can undo/redo.

Geometric angle

Hilaire Fernandes — Wednesday, October 26 2011

You need to install Java to play this file.

Distance and numeric

Hilaire Fernandes — Saturday, October 15 2011

You need to install Java to play this file.

Homothety

Hilaire Fernandes — Wednesday, October 12 2011

You need to install Java to play this file.

Rotation en degré

Hilaire Fernandes — Wednesday, October 5 2011

You need to install Java to play this file.