## 8 Reputation

17 years, 74 days

## Seemingly simple convolution takes forev...

Maple
I have a maple worksheet (attached) that calculates a 2-D convolution. Should be easy, I would guess. The convolution of a gaussian and a gaussian is very fast-- this has a simple analytical result anyway. A gaussian and a sinc function can take a couple of minutes... and a gaussian and a bessel function takes longer than I can allow! I think I must be missing something here. I've tried various things, interchanging "int" and "Int" for the integration, and also seting digits to something low, by using evalf. Sometimes it just maxes out all available memory before grinding to a halt, in other trials it will allocate about 300 MB and churn for hours. The worksheet is attached. I'd appreciate the advice.

## Can't plot proc - why?...

Maple
Hi, I have a proc that generates a "piston" plot in 2-D. I generate this with a procedure. Calling the procedure works, but calling it from Plot3d doesn't. I'm really not sure why. I'd appreciate the help. My stuff is below: Diameter := 46; Shape := proc (x,y) if((x^2+y^2)^(0.5) <>

## Literals and BVP DAEs...

Maple
Hello, In C one can use the preprocessor to #define a string literal to be inserted elsewhere in the code. Is there a way to do something like this in Maple? I ask because I am defining a BVP that includes another function as part of the derivitive, and dsolve rejects this, saying that it can't handle a BVP differential algebraic equation (I dont know why it can't do it!). Inserting the expression in place of the reference to the function gives no problem. Thanks

## Arrays of equations and the Numeric BVP ...

Maple
Hello, I'd like to use the BVP solver to find the numeric solution to a large set of differential equations. The thing is, I have about 60 equations differing only by constants in the derivitave. Instead of typing in a set 60 equations with different constants, is there an easy way I can create an array of equations and use it with dsolve? Thanks!
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