format the y tick labels

hello,

How can I format the y tick labels in e-notation? (note: I entered those exact labels as numbers in the form I want them to appear) but I still want them to appear in e-notation. Is there a way to do this when I edit the figure properties?

Thanks

Answer 1

[Sara]

If you want to change the format of the y-axis:

y = get(gca,'ytick');
yy = cell(numel(y),1);
for i = 1:numel(y)
  yy{i}=sprintf('%10.3e',y(i));  %%CHOOSE PRECISION
end
set(gca,'yticklabel',yy)

[Seldeeno]

Thanks...but how can I use the "10^x" notation instead?

[Sara]

You can't automatically. You'll have to replace the ticks with the text command. This may do it for you:

http://www.mathworks.com/matlabcentral/fileexchange/16003-tick2text--create-easy-to-customize-tick-labels

[Seldeeno]

This is very complicated for non-programmers. All I need is just how to print on the y-scale, values like 10^-20, 10^10 and so on

Thanks

[Sara]

Are you using plot or semilogy or loglog to plot your data?

[Seldeeno]

I am using plot

[Sara]

can you attach a sample of data or a plot of your data?

[Seldeeno]

This is the snippet I have. In this part, the data might take values that go from 10^-10 to 10^4 and I want the ytick to show such scale (although the code below is been uniformed).

    clc
clear
axis([0 6 0 9])
grid on
hold on
% Initially, the list of points is empty.
xy = [];
n = 0;
% Loop, picking up the points.
disp('Left mouse button picks points.')
disp('Right mouse button picks last point.')
but = 1;
while but == 1
    [xi,yi,but] = ginput(1);
    plot(xi,yi,'ro');xx(n+1)=xi;yy(n+1)=yi;
    n = n+1;
    xy(:,n) = [xi;yi];
end
% Interpolate with a spline curve and finer spacing.
t = 1:n;
ts = 1: 0.1: n;
xys = spline(t,xy,ts);
% Plot the interpolated curve.
plot(xys(1,:),xys(2,:),'b-');
hold off

[Sara]

The issue is that if you use "plot" and the data range is that large, you won't see anything 1 or 2 order of magnitude lower that the maximum value. Try adding at the end and see if it solves your problem:

y = get(gca,'ytick');
tick2text(gca,'axis','y','convert',1,'yformat',@(y)sprintf('%.0f%s10^%.0f',y ./ 10.^floor(log10(y)),char(215),floor(log10(y))))

you need to download tick2text

[Seldeeno]

I thank you for your continuous help. My last question is that, for one of the figures, I want to show how data is behaving even on a small scale. Now I can normalize data but I want to enforce placing just two values on the y-axis: Just 10^-5 and 10^-1. How can I do this using your last hint?

[Sara]

It needs to be modified for negative numbers so that you have something like 10^-^number. otherwise the number won't be at the exponent. Is that clear enough?

[Seldeeno]

forgive me for asking more, but as a non-programmer, I thought it would be easy (although tricky) to have such thing possible. What thing do I need to modify?

Thanks

[Sara]

This will work only if your y axis is always < 1:

tick2text(gca,'axis','y','convert',1,'yformat',@(y)sprintf('%.0f%s10^-^%.0f',y ./ 10.^floor(log10(y)),char(215),-floor(log10(y))))

[Seldeeno]

Probably you didnt get my point, as all I wanted was to force that I print on the y-axis just two values like: 10^0 and 10^5 (just as ytick). Can I just do this?

[Seldeeno]

I made a progress with this code, but why are the yticks it overlapping the y-axis?

ax = subplot(1,1,1);
   plot(x,y);
   title('Modified tick marks');

     set(ax, 'ylim', [0 9]);
tick2text(gca,'axis','y','convert',1,'yformat',@(y)sprintf('10^%.0f',y))
hx = getappdata(ax, 'YTickText');
set(hx, 'Rotation', 0, 'fontsize', 8, 'horiz', 'left');

[Sara]

It's the:

'horiz', 'left'

command, try taking it away. Note, you may want to do:

set(gca,'fontsize',8)

so that all the ticks are of the same size.

[Seldeeno]

Sara, you are great. Thank you for your help :)