## JacquesC

Prof. Jacques Carette

## 2386 Reputation

19 years, 65 days
McMaster University
Professor or university staff

## Social Networks and Content at Maplesoft.com

From a Maple perspective: I first started using it in 1985 (it was Maple 4.0, but I still have a Maple 3.3 manual!). Worked as a Maple tutor in 1987. Joined the company in 1991 as the sole GUI developer and wrote the first Windows version of Maple (for Windows 3.0). Founded the Math group in 1992. Worked remotely from France (still in Math, hosted by the ALGO project) from fall 1993 to summer 1996 where I did my PhD in complex dynamics in Orsay. Soon after I returned to Ontario, I became the Manager of the Math Group, which I grew from 2 people to 12 in 2.5 years. Got "promoted" into project management (for Maple 6, the last of the releases which allowed a lot of backward incompatibilities, aka the last time that design mistakes from the past were allowed to be fixed), and then moved on to an ill-fated web project (it was 1999 after all). After that, worked on coordinating the output from the (many!) research labs Maplesoft then worked with, as well as some Maple design and coding (inert form, the box model for Maplets, some aspects of MathML, context menus, a prototype compiler, and more), as well as some of the initial work on MapleNet. In 2002, an opportunity came up for a faculty position, which I took. After many years of being confronted with Maple weaknesses, I got a number of ideas of how I would go about 'doing better' -- but these ideas required a radical change of architecture, which I could not do within Maplesoft. I have been working on producing a 'better' system ever since.

## Physics exercise...

Maple
I have one awful, long way to solve the problem below, but I am sure there is also an elegant solution; unfortunately, it currently escapes me. Consider a rigid sphere of radisu 1 and center at 0 that rotates about its center. The angular velocity is omega(t) = Vector([ cos(t), sin(t), sqrt(3) ]). Does the path of the point starting at (0,0,1) ever reach the same point at a later time?

## Is there a way to do this? [probably a ...

Maple
From an exercise in "Game Physics", we have the following piecewise position vector r. We wish to show that it is well-defined (as well as twice differentiable) at 0. The goal of the exercise is then to show that the Normal vector is not even continuous. So we try: ```p1,p2 := <t,t^3,0>, <t,0,t^3>; r := piecewise( t<0, p1, p2); limit(r,t=0,left);``` and unfortunately that limit gives RTABLE(149559852,MATRIX([[t], [t^3], [0]]),Vector[column]) as a result! The obvious thing to try next is to "push in" the piecewise into the components. But the

## Fast dialog-less entry of equation label...

Maple
Is there a keyboard-only way to enter equation labels that will not 'zap' the focus away to a dialog box just to enter a label? While the 'look' of the equation labels is kind of nice, I find entering them extremely annoying (zapping focus is really awful UI design).

## Maple 10 Mac-only problem?...

Maple
A user in Ireland is trying to learn Maple programming, and got stuck on trying to reproduce the examples on p.49 of the Introductory Programming Guide. First, I suspected it might have had to do with 2D mode (it doesn't, it works on Windows), so I asked him to try in the TTY version. The results there were really weird: What could be the problem? Is this Mac-only? Is this some locale issue?

## Who is behind ScientificComputing blog?...

Does anyone know who the author of the Scientific Computing blog on blogspot?
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