Previous Page Next Page Contents

Type::ConstantIdents -- set of constant identifiers in MuPAD

Introduction

Type::ConstantIdents is the set {PI, EULER, CATALAN}.

Call(s)

contains(Type::ConstantIdents, obj)

Parameters

obj - any MuPAD object

Returns

see contains

Related Functions

contains, indets, Type::Constant

Details

Example 1

MuPAD implements PI as the identifier PI.

>> domtype(PI)
                                 DOM_IDENT

However, PI is constant (although rumors keep raising their heads that China, Alabama, or whoever it may be next time had tried to change its value by means of a legislative process):

>> testtype(PI, Type::Constant)
                                   TRUE

Still, indets regards PI as an identifier with no value (which is syntactically correct), and you can even use PI as an indeterminate of a polynomial:

>> indets(PI/2*x);
   poly(PI/2*x)
                                  {x, PI}
      
                          poly(1/2 PI x, [PI, x])

To find the ``real'' indeterminates, use the following call:

>> indets(PI/2*x) minus Type::ConstantIdents
                                    {x}

Example 2

Assume you want MuPAD to regard the identifier KHINTCHINE as a constant. (Probably, it should represent the Khintchine constant K, which is approximately 2.685452, but we will not implement this.) First of all, you should make sure that the identifier does not have a value yet and protect it:

>> testtype(KHINTCHINE, DOM_IDENT);
   protect(KHINTCHINE, Error)
                                   TRUE
      
                                   None

Next, add KHINTCHINE to Type::ConstantIdents (note that we have to unprotect the identifier Type, because Type::ConstantIdents is a slot of it):

>> old_protection := unprotect(Type):
   Type::ConstantIdents := Type::ConstantIdents union {KHINTCHINE}:
   protect(Type, old_protection):
   Type::ConstantIdents
                     {PI, EULER, CATALAN, KHINTCHINE}

Now, MuPAD regards KHINTCHINE as a constant:

>> testtype(sin(PI + KHINTCHINE), Type::Constant)
                                   TRUE
>> solve(x^2 = KHINTCHINE)
                               1/2                    1/2
               {[x = KHINTCHINE   ], [x = - KHINTCHINE   ]}

Changes




Do you have questions or comments?


Copyright © SciFace Software GmbH & Co. KG 2000