Differentation in Ada?

Differentation in Ada?

[Bill Ward]

  I can't seem to find much on this but I would like to make a function
that has to utilize differentation.  Is there a library around that would
help me to do this or do I need to do the differentation manually?

Re: Differentation in Ada?

[David C. Hoos]

Without more specifics, it's hard to know just what would be suitable for
your problem.

For example, I could envision a differentiation function in Ada with the
following profile:

function Derivitave_Of
     (The_Function : Function_Access
       At_The_Value : Float;
       Using_The_Interval : Float := 0.00001) return Float;

where the type Function_Access is defined by

type Function_Access is access function (X : Float) return Float;

and where the body of Derivative returned the result

return (F (X + 0.5 * I) - F (X -0.5 * I) / I;

where TheFunction has been renamed to F
           At_The_Value has been renamed to X
  and   Using_The_Interval has been renamed to I

Such an approach will give suitable results for many cases, but sometimes
it will not.

For a list of books on numerical methods, see:
http://www.ericweisstein.com/encyclopedias/books/NumericalMethods.html.

----- Original Message ----- 
From: "Bill Ward" <bill_Ward@realitycoder.com>
Newsgroups: comp.lang.ada
To: <comp.lang.ada@ada-france.org>
Sent: Thursday, January 22, 2004 11:52 AM
Subject: Differentation in Ada?


>   I can't seem to find much on this but I would like to make a function
> that has to utilize differentation.  Is there a library around that would
> help me to do this or do I need to do the differentation manually?
> _______________________________________________
> comp.lang.ada mailing list
> comp.lang.ada@ada-france.org
> http://www.ada-france.org/mailman/listinfo/comp.lang.ada
> 

Re: Differentation in Ada?

[Bill Ward]

On Thu, 22 Jan 2004 13:40:33 -0600, David C. Hoos wrote:

> Without more specifics, it's hard to know just what would be suitable for
> your problem.
> 
> For example, I could envision a differentiation function in Ada with the
> following profile:
> 
> function Derivitave_Of
>      (The_Function : Function_Access
>        At_The_Value : Float;
>        Using_The_Interval : Float := 0.00001) return Float;
> 
> where the type Function_Access is defined by
> 
> type Function_Access is access function (X : Float) return Float;
> 
> and where the body of Derivative returned the result
> 
> return (F (X + 0.5 * I) - F (X -0.5 * I) / I;
> 
> where TheFunction has been renamed to F
>            At_The_Value has been renamed to X
>   and   Using_The_Interval has been renamed to I
> 
> Such an approach will give suitable results for many cases, but sometimes
> it will not.
> 
> For a list of books on numerical methods, see:
> http://www.ericweisstein.com/encyclopedias/books/NumericalMethods.html.
> 
> ----- Original Message ----- 
> From: "Bill Ward" <bill_Ward@realitycoder.com>
> Newsgroups: comp.lang.ada
> To: <comp.lang.ada@ada-france.org>
> Sent: Thursday, January 22, 2004 11:52 AM
> Subject: Differentation in Ada?
> 
> 
>>   I can't seem to find much on this but I would like to make a function
>> that has to utilize differentation.  Is there a library around that would
>> help me to do this or do I need to do the differentation manually?
>> _______________________________________________
>> comp.lang.ada mailing list
>> comp.lang.ada@ada-france.org
>> http://www.ada-france.org/mailman/listinfo/comp.lang.ada
>>

Well I would like to calculate the velocity of a particle travelling along
a curve that is rotating around a fixed point:
          _
   v = [ dr ]   _   _
       ------ = w X r
       [ dt ] 

r being the distance from the particle to the fixed point.
t is time
w is the anular velocity

Re: Differentation in Ada?

[Stephen Leake]

"Bill Ward" <bill_Ward@realitycoder.com> writes:

> Well I would like to calculate the velocity of a particle travelling along
> a curve that is rotating around a fixed point:
>           _
>    v = [ dr ]   _   _
>        ------ = w X r
>        [ dt ] 
> 
> r being the distance from the particle to the fixed point.
> t is time
> w is the anular velocity

So all you need are Cartesian vectors and cross products. See
http://www.toadmail.com/~ada_wizard/ada/sal.html.

-- 
-- Stephe