## 15 Reputation

13 years, 119 days

## Solving a system of recurrence relations...

Maple 14

Hi,

I'm using Maple 14 and I'm trying to solve a system of recurrence relations with initial conditions (a Vector Autoregressive model). The system is

const:=Vector[column]([0.009421681, -0.0005441856]):
lagY:=Vector[column]([0.796519372, 0.0179147112]):
lagZ:=Vector[column]([0.133049059, 0.5240695764]):
A:=<<const>|<lagY>|<lagZ>>;

eq1:=y(t) = A[1, 1] + A[1, 2]*y(t - 1) + A[1, 3]*z(t - 1);
eq2:=z(t) = A[2, 1] + A[2, 2]*y(t - 1) + A[2, 3]*z(t - 1);

## How to use LibraryTools[Save]?...

Maple 14

Hi,

I want to put some code into a Maple library. I'm new to producing packages. The following code runs OK, but when I try to use one of the procedures added by the LibraryTools[Save] command, Maple returns

input: MySum(a, b);
output: MyMapleLibrary:-MySum(a, b)

Why does Maple return an unevaluated call to MySum?

The code is below:

restart:
with(LibraryTools):

MyMapleLibrary:=module()
description "A sample Maple library.":

## Make the standard Maple library write-pr...

Maple 14

Hi,

In chapter 2 of the Advanced Programming Guide, it says:

"Important Always ensure that the standard Maple library is write-protected to avoid saving expressions in it. If you accidentally save something to the standard Maple library, you may need to restore the original from media on which you obtained the Maple software".

How do I make the standard Maple library write-protected? Is it by marking as read-only the following folder?

## How to print percetages and group digits...

Hi,

I'm developing an application in Maple 14. I'm using the code below to print a percentage:

# Printing a percentage.
x:=0.7569:
printf("The value of x is %.1f%%%", x*100);

Is this the right way to print a percentage?

I also want to group digits (as in 1,959), but don't know how to do it.

Carlos Mallen

## How to test for convexity...

Maple

Hi,

I'm using Maple 14 and have a function in several variables, which I want to minimize. As far as I know, to guarantee that NLPSolve (from the Optimization package) is really finding a global minimum, this function must be convex.

What is the best way to test for convexity in Maple?