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How to set YTickLabel in double y-axis plot?

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Albert Bing
Albert Bing on 22 Mar 2016
Edited: dpb on 23 Mar 2016
The simplified code is as following:
x=[2,3,4,5,6,7];
y1=[ 1, 1, 1.2, 1.2, 1, 1];
y2=[ 0, 0.01, 0.02, 0.02, 0, 0.01];
fig1 = figure;
[ax,h1,h2] = plotyy(x,y1, x,y2, 'plot');
set(get(ax(1),'YLabel'),'String','y1','fontsize',14)
set(get(ax(2),'YLabel'),'String','y2','fontsize',14)
legend('y1','y2');
xlabel('x')
ylim(ax(1), [0.7, 1.3])
ylim(ax(2), [0, 0.03])
print(fig1, '-dpng', 'test1')
The figure plot is like
I wanted to set the digits of YTick, so I tried something like
set(get(ax(1),'YTick'), [1.00, 1.05, 1.10, 1.15, 1.20]);
set(get(ax(1),'YTickLabel'), [1.00, 1.05, 1.10, 1.15, 1.20]);
or
set(get(ax(1),'YTick'), {'1.00', '1.05', '1.10', '1.15', '1.20']);
set(get(ax(1),'YTickLabel'), {'1.00', '1.05', '1.10', '1.15', '1.20']);
or
set(get(ax(1),'YTick'), str2mat('1.00', '1.05', '1.10', '1.15', '1.20']);
set(get(ax(1),'YTickLabel'), str2mat('1.00', '1.05', '1.10', '1.15', '1.20']);
All went wrong.
So my question is, how to set the digits of y axis label?
And why the left YTick is from 1.0 to 1.2 but leaves all other ticks?
And more generally, how to handle this `gca` properties?

Accepted Answer

dpb
dpb on 22 Mar 2016
Edited: dpb on 23 Mar 2016
Isn't it annoying that plot isn't intelligent-enough to use a consistent numeric format for tick labels??? I've complained about this for almost 30 years now... :(
Anyway, it's relatively easy to fix...
Long-winded way; easier to see what did...
yt=get(hAx(1),'ytick'); % retrieve the tick marks from desired axes
set(hAx(1),'yticklabel',num2str(yt.','%.2f')) % set with a desired format same values
You can, of course, dispense with the temporary -- easiest to write w/o getting fouled up with parentheses nesting if start from inside out...
set(hAx(1),'yticklabel',num2str(get(hAx(1),'ytick').','%.2f'))
NB: the transpose; it's important as the tick values are returned as a row vector and num2str needs a column vector or the values will all be returned as a single long string, not an array of strings.
  3 Comments
Albert Bing
Albert Bing on 22 Mar 2016
Ah, transpose, thank you!
So that better be
num2str(yt.', '%.2f')

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More Answers (1)

Mike Garrity
Mike Garrity on 22 Mar 2016
Or in R2016a:
ax(1).YAxis.TickLabelFormat = '%.2f';

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