## Jean-Michel

Dr. Jean-Michel Collard

## 235 Reputation

19 years, 10 days
Western suburb of Paris, France
-Differential Topology -Quantum Cosmology PhD in Mathematics MSc in Astrophysics That's all Folkx ("Looney Tunes")

## Maple and CUDA?...

Maple

Hello All,

This morning I tested for the first time Maple's CUDA capablities.

(I took the following example on the Maplesoft website)

with(LinearAlgebra); CUDA:-Enable(false); CUDA:-IsEnabled(); a := RandomMatrix(4000, datatype = float[8]); b := RandomMatrix(4000, datatype = float[8]); t := time[real](); c := a . b; time[real]()-t;
false
7.489
with(LinearAlgebra); CUDA:-Enable(true); CUDA:-IsEnabled(); a := RandomMatrix(4000, datatype = float[8]); b := RandomMatrix(4000, datatype = float[8]); t := time[real](); c := a . b; time[real]()-t;
true
Error, (in unknown) CUBLAS internal error
7.183

As we can see there is not significant improvment on my machine with/out CUDA.

(I don't understand the CUBLAS error)

My graphics card is a GTX960 4 Go GDDR and 1024 cores.

Voilà.

Jean-Michel

## A simple question I never dare ask ...

Maple

Hello All,

What is the Maple equivalent command for \$MaxNumber/\$MinNumber and \$MaxMachineNumber/\$MinMachineNumber (these should be 10^308/10^-308) found in Mathematica.

I never asked this question before because I do *not* like comparisons between Maple and Mathematica, as I said in a post some months ago.

Best :)

Jean-Michel

## How to simplify this result...

Maple 2015

How to simplify this result in order it returns the correct answer i.e : sqrt(Pi)/2*exp(-2*abs(x))  -infinity<x<infinity.

int(exp(-t^2-x^2*t^-2), t = 0 .. infinity);

print(`output redirected...`); # input placeholder
/
1 |
- |
2 \
/     /                    / 2            \
1   (1/2) |     |                    |t  + csgn(x) x|
- - Pi      |limit|exp(4 csgn(x) x) erf|--------------|
2         \     \                    \      t       /

/  2            \                  \\
|-t  + csgn(x) x|                  ||
- exp(4 csgn(x) x) - erf|---------------| + 1, t = 0, right||
\       t       /                  //

\
(1/2)|
+ Pi     | exp(-2 csgn(x) x)
/

It comes from Peirces's Tables No 510.

I have notice that Maple's integrator is very efficient.It is one  integral from these tables that Maple can't handle directly.

To be contined later.

Best,

Jean-Michel

## Simplification of...See down...

Hello all,

It was noticed by Dr Corless in his book Maple...7 that sin(3*arcsin(x)) is equal to 3*x-4*x^3.

At the time Maple 7 couldn't do that.

Now with Maple 18 here is what I did without success:

convert(sin(3*arcsin(x),exp) (long expression...) and then simplify(%)...Ugly expression.

How can I FORCE Maple to return the polynomial in x (if possible at all) ?

Kind Regards

JMC

## zooming and paning ...

Maple

Hello,

What is the combination key for zooming in/out on a Maple 3D graphic?

It seems I have forgotten... (CTRL+left mouse button does not work)

Thankx

JMC

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