Re: grid outside border

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

I looked into this issue of the grid line and tics to the right of the 
right border.  There is a lot of code for the tics, and I notice a 
comment in the code:

    /* FIXME HBB 20010121: keeping adding 'step' to 'tic' is
     * begging for rounding errors to strike us. */
    /* HBB 20010410: ... and strike they did :-( */

So there is probably an issue having to do with that.  Of course, one 
thing that could be done is a sanity check to make sure no tics are 
drawn if outside xleft, xright, xbot, xtop.  But those variables are not 
in the same C file....  Also, there should be a bit of code that would 
round the border up to 2.0 if [0:1.99805].  What I mean, is that the 
range should probably be rounded to the nearest, oh, 1/2% of the length. 
 That is, when it comes to the final computation of the range, treat 
1.99805 as follows

xmax - xmin = 1.99805

(xmax - xmin)*0.005 = 0.0099903

which means we should round to the nearest 0.01, i.e. 1.99805 rounds to 
2.0.  It is a little bit difficult to imagine an elegant algorithm to do 
this, but it may involve working with the exponents of floats in 
exponential notation.  (Can't think of any C constructs to do that.)  Or 
perhaps working with logarithms.

Not proposing this be done, but I hope you catch my drift.

Dan