Maths encyclopedia and lessons  
Search

Mathematics Encyclopedia and Lessons

 
     
 

Lessons

Popular
Subjects

algebra
arithmetic
calculus
equations
geometry
differential equations
trigonometry
number theory
probability theory
more
 

References

applied mathematics
mathematical games
mathematicians
more
 
 

Multiscale calculus

Multiscale calculus is a discrete counterpart to continuous calculus as originally developed by Isaac Newton. It is a computer-friendly adaption to the laws of calculus.

Contents

How it works

In discrete calculus the function values can be only be accessed at discrete positions and through three multiscale operators.

The multiscale operators

大 : f \rightarrow f(0)

T : f(x) \rightarrow f(x+1)

Z : f(x) \rightarrow f(x/2)

Description of the operators

1. The evaluation operator 大 (pronounced "da"), returns the functions value at the origin.

2. The translation operator T shifts the function by integer value. Together with 大, evaluations at integer positions are possible.

3. The dilatation operator Z allows a zoom into the function by a factor of 2.

Computer implementation

 // Licensed under the GNU General Public License
 interface Dadim {
    public Object da();
    public void trans(int dir, int length);
    public Dadim zoom(int dir);
 }

For accelerated access to double values in the context of numerical evaluation there is an important subclass DDadim.

 interface DDadim extends Dadim {
    public double doubleValue();
 }

Example: the differential operator

The differential operator d has a discrete counter part Δ. To define it in multiscale calculus, the three operators have to be implemented:

大 Δ = 大 T - 大

T Δ = Δ T

Z Δ = Δ Z

In order to evaluate the differential of f(x) we apply Z to zoom into the desired precision, then T to shift the argument and then 大 for evaluation.

大 Δ f(x) = f(1) - f(0)

Function isomorphism

Continuous functions can be directly interpreted in the context of multiscale calculus just be restricting the access methods. Vice versa, multiscale functions can be returned into continuous functions by limiting the resolution to infinity.

f(x) = lim_{n\to\infty} T^{\lfloor 2^n x\rfloor}f

01-04-2007 01:18:14
The contents of this article are licensed from Wikipedia.org
under the GNU Free Documentation License. How to see transparent copy