Start plot errorbar() at 0 ?

Hello,

In my matlab script, i use errorbar() to plot my data, but i wish it could start from 0 (for the y-axis).

Do you have an idea ?

Thanks !

Here is my sample :

>> x

moyenne(2:2,1:end)

ste(1:1,1:end)

x =

     1     2

ans =

   64.7573   36.0701

ans =

    4.0268    4.6105

>> errorbar(x,moyenne(2:2,1:end),ste(1:1,1:end));

Answer 1

[Jos (10584)]

You can change limits of the axis using the commands YLIM

CurYLim = ylim % get the current Y limits
ylim([0 CurYlim(2)]) % change the lower limit

Answer 2

[Remi Chaussenot]

Thanks for your quick answer.

In the mean time, i ended with :

oldy = get(gca, 'ylim')

if oldy(1) > '0'
    oldy = [0 oldy(2)]
end

set(gca,'YLim',[0 oldy(2)])

Which one is better ?

Thanks :)

[Michael Haderlein]

First, please note that the '' in your if statement are making things wrong. You actually compare the lower limit with the string '0'. This means, the value of the ascii sign '0' will be used which is 48. So you set oldy(1) to zero only if it was at least 49 before. That's not what you wanted, I guess.

However, your code works because the if structure makes nothing at all. The reason is that you don't even use the value of oldy(1) in your set statement. So you can simply delete the entire if statement. What you then end up with is basically the same as Jos' answer. If you use ylim() or set(handle,'ylim',..) is up to you.

[Remi Chaussenot]

Hello,

I had some difficulties to understand your message yesterday, so i reply just today.

"You actually compare the lower limit with the string '0'. This means, the value of the ascii sign '0' will be used which is 48. So you set oldy(1) to zero only if it was at least 49 before. That's not what you wanted, I guess."

No, you guess well. I do not know that it use the ascii value with ' ' (well, started with MATLAB a few weeks ago, more used at PHP/JS...).

"The reason is that you don't even use the value of oldy(1) in your set statement. So you can simply delete the entire if statement."

Damned, i just read my code today. Yeah, the if statement is truly useless, because the set is outside ! Was very tired yesterday..

Thanks for opening my eyes Michael :)

Edited like that :

          CurYLim = ylim 
          if CurYLim(1) > 0
              ylim([0 CurYLim(2)])
          end

Seems okay ? Thanks Michael and Jos :-)