Tabulated values for a function

[aaronfude]

Hi,

This is not really a C/C++ question. Suppose I have a function double
f(double x) that takes a long time to compute. Is there a tool
available that would take this function and would generate C/C++ code
for this function which operates via tabulated values?
Thanks
Aaron Fude

[Victor Bazarov]

<aa*******@gmail.com> wrote...

This is not really a C/C++ question.
There is no such thing as "a C/C++ question". It's either a C question
or a C++ question.
Suppose I have a function double
f(double x) that takes a long time to compute. Is there a tool
available that would take this function and would generate C/C++ code
There is no such thing as "C/C++ code". It's either C code or it's C++
code.
for this function which operates via tabulated values?

There are several tools on the market that can do something like that.
They are OT here, however. Try alt.sci.math.mathematica.

V

[E. Robert Tisdale]

aa*******@gmail.com wrote:

This is not really a C/C++ question.
Try sci.math.num-analysis.
Suppose I have a function double f(double x)
f(double x) that takes a long time to compute.
Is there a tool available that would take this function
and would generate C/C++ code for this function
which operates via tabulated values?

No.
I used Google

http://www.google.com/

to search for

+"interpolation" +"C++"

and I found lots of stuff including

http://www.mathtools.net/C_C__/Fitti...Interpolation/

[Thomas Matthews]

aa*******@gmail.com wrote:

Hi,

This is not really a C/C++ question. Suppose I have a function double
f(double x) that takes a long time to compute. Is there a tool
available that would take this function and would generate C/C++ code
for this function which operates via tabulated values?
Thanks
Aaron Fude

Many complex functions are implemented as table lookups.
Some use interpolation others are direct lookups. Often
times, this is a trade of speed for memory / code space.

--
Thomas Matthews

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Other sites:
http://www.josuttis.com -- C++ STL Library book
http://www.sgi.com/tech/stl -- Standard Template Library

[aaronfude]

Thomas Matthews wrote:

aa*******@gmail.com wrote:

Hi,

This is not really a C/C++ question. Suppose I have a function double f(double x) that takes a long time to compute. Is there a tool
available that would take this function and would generate C/C++ code for this function which operates via tabulated values?
Thanks
Aaron Fude

Many complex functions are implemented as table lookups.
Some use interpolation others are direct lookups. Often
times, this is a trade of speed for memory / code space.

Hi Thomas,

Thank you for such a useful response. Do you know if "sin" is
implemented as a lookup in libm? In either case, can you point me to a
C/C++ example of a funciton implemented as a lookup with interpolation?
Uh, sorry, C or C++ example. :)

Thank you!