atlas[kind] -  kind of a tensor 

Calling Sequence: 

    kind(T) 

Parameters: 

     T -any expression containing tensors, vectors, p-forms etc. 

Description: 

• In the atlas package one can declare: constants, functions, vectors, p-forms, tensors etc. Any undeclared  identifier is treated as 0-form i.e. as non-constan scalar  (see atlas[types]). User can construct any reasonable expressions from declared or undeclared objects.

 

• The kind procedure allows one  to find out what kind of tensor is an expression.

 

Examples: 

>	restart: with(atlas):

 

Declare constants:  

>	Constants(alpha,beta,C,lambda);

 

(2.1)

 

Declare functions:  

>	Functions(f=f(x,y),y=y(z));

 

(2.2)

 

Declare vectors:  

>	Vectors(E[j],X,Y,Z,U[i]);

 

(2.3)

 

Declare forms:  

>	Forms(e[j]=1,omega=2,theta=p);

 

(2.4)

 

Declare Tensors:  

>	Tensors(T=[n,k]);

 

(2.5)

 

Let's find out the kind of some objects and expressions 

>

kind(z);

 

(2.6)

 

>	kind(omega);

 

(2.7)

 

>	E[j]-f*Y; kind(%);

 

 

	(2.8)

 

>	T&.d(theta); kind(%);

 

 

	(2.9)

 

>	d(z)&^d(x); kind(%);

 

 

	(2.10)

 

>	d(z)&^d(f)+omega; kind(%);

 

 

	(2.11)

 

Let's see "who is who" 

>

Who();

 

(2.12)

 

>

 

See Also:  

atlas, atlas[Constants], atlas[Functions], atlas[Forms], atlas[Tensors], atlas[Who].