Re: [Axiom-math] Axiom: Printing multiple variables in axiom.

[Bill Page]

On 11/8/07, Constantine Frangos <address@hidden> wrote:
>
> In the function below, I tried to use the following commands
>
> )display value Acon
> print(['Acon = Acon])
>
> to print one or more variable.
>
> However, I get very strange behaviour and error messages, so had to comment
> them out. There might be a bug somwhere in my program.
> ...

What do you mean by "strange behaviour"? Do you mean for example the
error message:

(12) -> print('Aconnull = Aconnull)
   There are 3 exposed and 0 unexposed library operations named
      equation having 2 argument(s) but none was determined to be
      applicable. Use HyperDoc Browse, or issue
                            )display op equation
      to learn more about the available operations. Perhaps
      package-calling the operation or using coercions on the arguments
      will allow you to apply the operation.

   Cannot find a definition or applicable library operation named
      equation with argument type(s)
                              Variable Aconnull
                       List Vector Expression Integer

      Perhaps you should use "@" to indicate the required return type,
      or "$" to specify which version of the function you need.

------

This error should be expected since you are trying to produce an
equation (which like everything in Axiom must have a type) between two
things of quite different kind. I cannot think of any equation which
has Variable on one side and List on the other. You might try to
construct something of type:

   Equation Polynomial Integer

For example

(1) -> x=1

   (1)  x= 1
                                Type: Equation Polynomial Integer

In this equation both sides of this equation can be considered Polynomials.

In this case maybe you want to create an equation of type:

  Equation List Vector Expression Integer

Like this:

  [['Aconnull]] = Aconnull

Now the lefthand side can be interpreted as a 'List Vector Expression
Integer' so the expression

  print([['Aconnull]] = Aconnull)

is ok.

Maybe you should not be trying to create an equation just to print a result?

Probably

  output("Aconnull =", Aconnull)

is more like you intended to do.

The command

  )display values

is a command. As such it is not intended to be used inside of a
function definition such as

testkinemat1 ==
--)read expandsincos.input
 Acon := matrix([[1 , 0 , Lo1*sin(phi) , -sin(phi)*a , 0 , 0 , 0 , 0 , 0],_
[0 , 1 , -Lo1*cos(phi) , a*cos(phi) , 0 , 0 , 0 , 0 , 0],_
...

as you wrote above. Why are you writing?

  testkinemat1 ==

This does not make sense to me in your code. Are you intending to use
this name testkinemat1 for some purpose later? This is not the usual
way in which one would use a definition like this. Perhaps you can
explain what you really want to do with this code.

If you forget about trying to define the function testkinemat1, then you can use

  )display values

in the normal way in the rest of you code because this is just a
series of expressions and command to be evaluated. This works fine for
me.

Regards,
Bill Page.