Plot only for positive y

I have

      plot(x,y)
      hold on
      plot(x,z)
      hold on
      plot(x,w)

I need to have a plot for only positive y and z. I try to write

ylim([0,yMax])

But I do not know how to set for yMax. Please advise.

[OCDER]

 ylim([0,max(y)])

?

Curious, why do you have to plot(x, z) twice? Also, do you want to plot the maximum of y or z?

 ylim([0, max([y(:); z(:)]))

[alpedhuez]

I have sought a simpler way to specify Y axis so that the figure only shows positive part of the Y-axis.

Answer 1

[OCDER]

 NEW ANSWER

 ylim([0 inf])  %Will automatically compute the limit where "inf" is used

 OLD ANSWER

 ylim([0, max([y(:); z(:); w(:)]))
 %will plot positive values of y axis from 0 to the maximum of either your y or z or w values.

[alpedhuez]

would be efficient that a future version has an option for ylim that automatically calculates maxes of all the y-axis variables.

[OCDER]

Actually, there was an easier solution. I'll update the answer:

ylim([0 inf]) %will automatically compute the limit where "inf" is used

https://www.mathworks.com/help/matlab/ref/ylim.html#buob47u-limits

[Jack]

this doesnt seem to work on my graph bit confused any ideas how I could be messing it up? im putting it after the plot(x,y) and have tried after title labels and after hold on so bit confused.