Re: Compiling

[Daniel J S. <dan...@ie...>]

Alexandre Felipe wrote:
> Yes, I know that increase the number of samples and plot with dots may 
> work. this could resolve the problem until the user zoom the chart.
> Whatever is the GNU tarball it appeared with the source code.
> 
> /Finding discontinuities (or determining whether a function
> is continuous in a given interval) is quite hard for an arbitrary
> function./
> /How exactly do you intend to do this?/
> 
> The user defined functions is not so arbitrary. and my analisis is for 
> simple functions
> supose that i know f(x) and g(x)
> 
> if(c = discontinuity of f){
>   if((g(x1) < c) != (g(x2) < c)) {
>     an treat it or only break the line betwen x1 and x2
>     or find the closer x3 of the discontinuity and plot two points there
>     one with the limit(f(x), x -> x3+) and other with limit(f(x), x -> x3-)
>     i don't know how the gnuplot handles it internaly but it handles
>          
>           plot '-' with lines
>                 1 2
>                 2 2
> 
>                 2 1
>                 2 1
>          e
>   }
> }else if(c = discontinuity of g betwen x1 and x2){
>    plot the function in c with the two lateral limits
> }
> 
> 
> it's easy to implement it recursively less than 1000 lines i think :D
> 
> discontinuities that i know
> 1/x - x = 0
> x < 0, x = 0
> gamma(x), x integer < 0
> floor(x), x integer
> it there are others is only specify
> so the returning value in each evaluation should carry information about 
> the discontinuity only for the
> working interval, 

If you know the limit points of your functions then there are ways to construct plots of multiple segments and achieve what you are looking for.  Take a look at some of the examples in the demos:

http://gnuplot.sourceforge.net/demo_4.4

In particular, the statistical distributions have some good examples:

http://gnuplot.sourceforge.net/demo_4.4/prob.html

Check out the gamma function plot.

Dan