# Maple fucntion minimize

1. Nov 30, 2005

### cva

Hello,

I have a problem with maple. My code is like this:

f(A1(v),A2(v),A3(v))

fm:=minimize(f,A1=-1..1,A2=-1..1,A3=-1..1)

so that I obtain a fm(v). But I also need to find A1(v),A2(v),A3(v) that minimize f.

Do you know any way to do this?

Best,

Cristian

2. Dec 3, 2005

### benorin

Use the location=true option for minimize, that is put

fm:=minimize(f,A1=-1..1,A2=-1..1,A3=-1..1, location=true);

by the way, if you need to know something of this nature, there's a reasonable chance of finding it in the help docs for whatever Maple command you are using. To get the help docs open for a Maple command,
like "minimize" put type

?minimize

3. Dec 6, 2005

### cva

Thanks for your reply. My problem is that all these variables are function of v. and I need to have the dependence A1(v),A2(v) and A3(v).
fm:=minimize(..., location=true) gives an array , but unfortunatley ,aple does not keep the order of the variables, every time is different.

For example:

fm[1] := 0.2075577438e-1, {[{A2 = 0.3304115674e-2, A3 = -.5155123546, A1 = 0.9409892271e-1}, 0.2075577438e-1]}
fm[2] := 0.2074929592e-1, {[{At = 0., A1 = .5315345998, A2 = 0.9928747436e-1}, 0.2074929592e-1]}
What I need is fm(v) and A1(v), ... for which correspondening to fm(v).

Cristian

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4. Dec 6, 2005

### cva

Thanks for your reply. My problem is that all these variables are function of v. and I need to have the dependence A1(v),A2(v) and A3(v).
fm:=minimize(..., location=true) gives an array , but unfortunatley ,aple does not keep the order of the variables, every time is different.

For example:

fm[1] := 0.2075577438e-1, {[{A2 = 0.3304115674e-2, A3 = -.5155123546, A1 = 0.9409892271e-1}, 0.2075577438e-1]}
fm[2] := 0.2074929592e-1, {[{At = 0., A1 = .5315345998, A2 = 0.9928747436e-1}, 0.2074929592e-1]}
What I need is fm(v) and A1(v), ... for which correspondening to fm(v).

Cristian

5. Dec 9, 2005

### benorin

A set in Maple uses {}'s while a list uses []'s, Maple will not keep the order of objects placed in sets (e.g., if, in Maple, you put Set:={a,b,c};, then Maple may display Set={c,a,b}, or any other arrangement as it pleases), but order is maintained in a list by Maple ((e.g., if, in Maple, you put List:=[a,b,c];, then Maple will always display List=[a,b,c]).

6. Dec 9, 2005

### benorin

You might also try using the Minimize command in the Optimization package:

>with(Optimization);

>?Minimize

should get you started.

7. Dec 10, 2005

### cva

Cristian

8. Jan 18, 2007

### cva

Hello,

Meanwhile I was able to solve the problem.

The ouptput of fm:=minimize(..., location=true) is an array which contains the value of minima and a set like in the eq down.

fm[1] := 0.2075577438e-1, {[{A2 = 0.3304115674e-2, A3 = -.5155123546, A1 = 0.9409892271e-1}, 0.2075577438e-1]}

In fact the set {[{A2 = 0.3304115674e-2, A3 = -.5155123546, A1 = 0.9409892271e-1}, is not giving values to A1,A2,A3 is just the rule that those variables have to obey in oredr to have minima. The values can be extracted with the help of the command subs, like this

subs({[{A2 = 0.3304115674e-2, A3 = -.5155123546, A1 = 0.9409892271e-1},[A1,A2,A3]) .
The rule is applied to the variables.