[scilab-Users] How to define set of numbers without some special numbers?

[Samuel GOUGEON]

If you want to avoid evaluating the function at special points and to 
connect
first neighbours accross special points, one has previously to remove these
ones from the list :
x=-100:100;
x2=setdiff(x,[0 -3 2]);
clf
plot2d(x2,1. ./x2 + 1. ./(x2 + 3) + 1. ./(x2 - 2));

If you want to manage divergent calculations (e.g. at some poles), try :
x=-100:100;
ieee(2);
y=1. ./x + 1. ./(x + 3) + 1. ./(x - 2); // example
clf
plot2d(x,y)  // no segment connected to |%inf| values are plotted

After this remark, you may set y value of  special x locations to %inf or
-%inf to use the same plotting feature (but buggy):
x=-100:100;
[v,kx]=intersect(x,[0 -2 3]);
y=sin(x/10);
y(kx)=%inf;
plot2d(x,y);   // see buggy segment (i am reporting it through bugzilla)

Regards
Samuel


----- Message d'origine -----
De : Christian Hoehle
Date : 21/05/2009 10:44:
> Hi all,
>
> i recently tried to do a plot of a function with a value range of (x |
> (-100 <= x <= 100) \ {0; -3; 2}).
> Any idea how to realize that?
> Most probably i just didn't find the manual's page describing definition
> of sets omitting special numbers... or yust didn't get the right keyword
> to search for ;-)
>
> Thanks for all hints.
>
> Cheers,
> Chris