Gradient: thought comparison of the codegen version and the symbolic version.
This is something I don't understand. There are two ways of obtaining the gradient of a function: (1) codegen uses auto-differentiation; (2) derive the partial derivative symbolically. Both can be translated into C or Fortran code, since my end goal is the C or Fortran code.
The documentation claims the auto-differentiation is more efficient. I don't understand. Any more complete views about this matter? Does auto-differentiation win both in accuracy and efficiency? Or perhaps there is a trade-off between efficiency and accuracy? I just wanted to hear more opinions from your experience. Thanks a lot!

Hi all,
If I have an expression and it involves computations with extremely large numbers. Double precision is bound to fail in my case.
And when I used Matlab 2007a's symbolic toolbox, which I believe uses Maple 10 or Maple 9's engine, it supposedly should always return correct value, because its symbolic, with infinite precision. But it still fails for some parameters which makes the numbers too large.
Now if I compute the same expression in Maple 11, it is even worse. The calculation fails for a lot more parameters. The failing parameter set for previous Maple version is now a subset of the failing parameter set for the Maple 11. The difference is huge -- Maple 11 gives wrong values almost all the time, even for very friendly parameters.

Hi all,
Did you discover the same mysterious thing about the command execution time in Maple?
Here is my observation:
If I have been using this session for a long time and then if I issue a long-processing command, such as simplification of a very complicated expression, etc. After a while, Maple will get into "steady state": it keeps running and running, without consuming more memory and showing more activity, the time even counts towards 10000 second, etc.
If based on this, I think the expression is really too complicated for it to simplify, then I am wrong.
After rebooting the PC, and relaunch Maple, and start the same command to simplify the same expression, it generated a result within 15 minutes, successfully...

What's wrong with my "asympt"?
Hi all,
I want to find out the order of growth/decay of expression CCP1(attached below). CCP1 is a sub-expression of my huge expression(which Maple couldn't handle).
The goal is to find the functional form for my expression as "v" and "t" approaches +infinity, so that I can bound the error after truncating it,
because I am using this as an integrand.
The original huge expression is known to be fast decay in "v" -- I suspect the asympotic order is of exp(-a*v)/(v+b)^n.
But this sub-expression might be decay, it may grow at +infinity.
The goal is to find out the asymptotic order of growth/decay so that when I combine with the results from other expressions I can get the overall decay order.

Is there a way to save results to file instead of the console/display?
My expressions got too long and they occupy huge space on screen and scrolling is horrible now. Of course I can hide the content of the display by using ":".
However, I do need to use(copy & paste to other applications) the very last output of results(it is very long).
Is there a way to specify or redirect the output to file so after a while I just need to open the output file to use that long expression?
Thanks a lot!