Re: extra tick marks at top x-axis: strategy?

[indium]

On Thu, Sep 08, 2011 at 10:24:18AM -0400, Ben Abbott wrote:
> 
> On Sep 8, 2011, at 10:17 AM, indium wrote:
> 
> > Hi all,
> > 
> > I have attempted to add extra tick marks to a plot by adding another
> > x-axis that is positioned on 'top'. But then the original plot is
> > 'blanked' by the following plot command. I saw this because the second
> > set of axes is not 'perfectly' overlapping with the first set (it quite
> > far off, actually).
> > 
> > Is this the way to make these second sets of tick mark labels? I'd
> > like to have for instance temperature on the x-axis on the bottom and
> > inverse temperature tick marks on the top axis.
> > 
> > If so, how do I realign those two axes? I have set the 'position' of the
> > two the same, but I think that due to margins needed for the labels,
> > title, etc, the axes do not overlap.
> > 
> > many thanks for any suggestions!
> 
> To make the axis on top transparent set its color to "none", and its position 
> to that of the bottom axis. The code below is untested, and ax_top and ax_bot 
> refer to the handles for the top and bottom axes.
> 
>       set (ax_bot, "activepositionproperty", "position")
>       set (ax_top, "position", get (ax_bot, "position"))
>       set (ax_top, "color", "none")
> 
> Ben
> 
> 

okay, thanks! 
for 'the record' I have put some commands together that work for me:

ax_bot=axes();                                                                
ax_top=axes();
set(ax_bot,'activepositionproperty','position')
set(ax_top,'position',get(ax_bot,'position'))
set(ax_top,'color','none')

x=1:10; y=sin(x) ; 
plot(ax_bot,x,y)      % this will be in the standard color (blue)
plot(ax_top,x,y,'or') % this will be red dots, associated with top axis

set(ax_top,'activepositionproperty','position')
set(ax_top,'xaxislocation','top')

xtt=(0:3)*pi;
xttl={'0','\pi','2\pi','3\pi'} % is \pi converted to the symbol?
set(ax_top,'xtick',xtt)
set(ax_top,'xticklabel',xttl)
grid


remarks:
1. In my case, \pi does not convert to the greek symbol.
2. Both 'activepositionproperty' settings are needed for aligment