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Topic: Re: Sine, cosine?
Replies: 16   Last Post: Aug 19, 1999 11:13 PM

 Messages: [ Previous | Next ]
 Jos De Laender Posts: 1 Registered: 12/12/04
Re: Sine, cosine?
Posted: Aug 17, 1999 3:52 PM

Steve Leibel wrote:

> One key difference between the word "function" as used in math and
> programming is that in math, a function is an association of x with f(x).
> In programming, you must specify the algorithm for obtaining f(x) from x.

I don't see the difference. I.e. I don't think there's a fundamental one : in
mathematics as well as in programming you have to 'specify' your function. Be it by
tabular methods , be it by series expansion , be it by another mathematical
expression ...

> Most mathematical functions could never be programmed, becase there are
> more functions than algorithms.

Is this true ? According to above , I would say it isn't. Of course I take now
abstraction of the feasibility to calculate it with sufficient accuracy in
reasonable time.

>
>
> Secondly, a function in a programming language may have global side
> effects, and often the "return" value is just a status or error code. To

Exposed to the wrong programming language , I'm afraid.Functions with global side
effects are in a lot of developped countries forbidden by law.

> use a very well-known example, printf() writes characters on a console,

A decent language calls a beast like printf() not a _function_ but a procedure.

> and returns an integer giving the number of characters written. I doubt
> that one C programmer in a thousand checks or uses the return value from
> printf(); and I doubt that one in a hundred even knows printf() returns a
> value.
>
> If a mathematical function were like a programming function, when you took
> the cosine of pi it would not only give you the answer, it would also turn

You make your comparison the wrong direction. A well developped programming function
acts like a mathematical function.

>
>
> In my opinion the use of the word "function" in programming is just a
> loose adaptation of the mathematical word, and has no significance beyond
> that.
>
> There is simply no similarity between a mathematical function defined as a
> particular subset of the cartesian product of two sets, and the usage in
> programming to mean a little bundle of code that executes an algorithm,
> manipulates its environment, and returns a value that is often not even
> regarded as important.
>
> Steve L

Date Subject Author
8/15/99 Dr Mike Ecker
8/15/99 Dr Mike Ecker
8/15/99 Kyle R. Hofmann
8/15/99 Loomis Philanthrope
8/16/99 Kyle R. Hofmann
8/17/99 Loomis Philanthrope
8/17/99 Kyle R. Hofmann
8/15/99 Steve Leibel
8/17/99 Jos De Laender
8/18/99 Steve Leibel
8/18/99 David Petry
8/18/99 Virgil Hancher
8/19/99 David Petry
8/19/99 Virgil Hancher
8/19/99 David Petry
8/19/99 Virgil Hancher
8/18/99 Steve Leibel