Re: Possible more TODO features

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

Ethan Merritt wrote:
> On Wednesday 14 March 2007 16:05, Daniel J Sebald wrote:
> 
>>set arrow 1 from -2,0 to -10,0 nohead lc rgb "black"
>>set arrow 2 from -2,0 to -2+10*cos(pi/3),0+10*sin(pi/3) nohead lc rgb "black"
>>set arrow 3 from -2,0 to -2+10*cos(-pi/3),0+10*sin(-pi/3) nohead lc rgb "black"
>>
>>1) I'd like the asymptotes to be dashed lines.  Is it possible to do so, 
>>I mean generally speaking for all terminals? 
> 
> 
> No. Not all terminals can draw dotted lines.  Them's the breaks.
>  
> 
>>2) Note how the lines are not clipped at the boundaries.  
> 
> 
> Correct. Only the plots themselves are clipped to the plot boundaries.
> That is a feature.
> Otherwise you obviously couldn't place arrows and labels in the borders.

Yes, I thought of that after I sent the original message.  But still, if one of the end points of the arrow is "plotboundary" or something then the arrow should no to clip there.


>>4) As Ethan mentioned, do this with lines so that clipping behaves as desired.  
>>But I then have to set up the sampling so that a sample point lands on (-2,0), 
>>and do this as parametric so that I can get portions of lines.  
> 
> 
> ???
> No idea what you are talking about with points, sampling, parametric.
> All garbage. If you want a line through (-2,0) with a defined slope S
> 
>   line1(x) = S*(x+2)
>   plot line1(x)
> 
> If you want only a portion of that line, you set bounds:
>   line1(x) = x < lower ? NaN : x > upper ? NaN : S*(x+2)

Right, that is what I meant.  But recall that gnuplot does an internal sampling when plotting so that you aren't sure that the point will start at (-2,0).  There could be a little bit of discrepancy that makes the lines not exactly right.

Dan