intercept of secondary axis

Hi,

Im plotting two lines using two axis. They are velocity and acceleration. My question is how can I make the 0 point on the two axis be at the same level? At the moment, the 0 on the secondary axis is inline with 50 on the primary axis.

plotyy(x,y1,x,y2,'plot');

Thank you

Answer 1

[Azzi Abdelmalek]

After plotyy add this:

yt=get(gca, 'ytick');
yt(1)=[];
set(gca,'ytick',yt)

[John]

Hi,

It gives an error:

Index of element to remove exceeds matrix dimensions.

[Azzi Abdelmalek]

I've edited the code, try again, if it don't work, post your code. And don't accept the answer before checking it

[John]

Hi,

Noting happened, no error either.

My code is:

plotyy(x,y1,x,y2,'plot');

[Azzi Abdelmalek]

please, post the code (allows copy past).

Answer 2

[Azzi Abdelmalek]

Try this

close; 
x=0:250;
y1=100*abs(sin(0.01*x)),
y2=10*cos(.04*x);
[ax,h1,h2]=plotyy(x,y1,x,y2,'plot');
yt=get(ax(1), 'ytick');
yt(1)=[];
set(ax(1),'ytick',yt)

[John]

That didn't work either, one axis is 50 and same level of the other axis is 0.

Thanks

[Azzi Abdelmalek]

What is the problem? the first axis or the second? Explain again clearly what do you want to get

[Azzi Abdelmalek]

It will be helpful if you post your code

[John]

All I have is 3 variables x, y1 and y2.

My code is: plotyy(x,y1,x,y2,'plot');

I'm trying to plot them on a graph with a secondary axis. But I need the the '0' point on both axis to be at the same level.

In the picture above, one axis is 50 and same level of the other axis is 0. I need the 0s inline.

Can this be done?

Thanks

[Azzi Abdelmalek]

Ok, I get it now, use

ylim=get(ax(1), 'ylim');
ytick=get(ax(1), 'ytick');
set(ax(2),'ylim',ylim,'ytick',ytick)

but you will loose the negative part