Thread Subject: semilogy loop problem

Hi all,
having trouble gettin a 'semilogy' plot. I have the command in a
'for' loop to plot about 20 lines using 'hold on' also. But when the
plot comes out its on a linear linear scale.
Ill appreciate any suggestions
thanks

Terence Mc Cartan wrote:
>
> Hi all,
> having trouble gettin a 'semilogy' plot. I have the command in a
> 'for' loop to plot about 20 lines using 'hold on' also. But when the
> plot comes out its on a linear linear scale.
> Ill appreciate any suggestions
> thanks

Have any zero or negative values in the data--that's the only case I can
recall where the axes were reset to linear.

That not being the problem, if you save the handle of the axes object
you can reset the scale property back to 'log'.

I had the same problem, I haven't figured out any solution yet.....Hoping some super guy can fix it....
It sounds like a bug definitely..



"Terence Mc Cartan" <mrterencemccartan@gmail.com> wrote in message <ef1ba8d.-1@webx.raydaftYaTP>...
> Hi all,
> having trouble gettin a 'semilogy' plot. I have the command in a
> 'for' loop to plot about 20 lines using 'hold on' also. But when the
> plot comes out its on a linear linear scale.
> Ill appreciate any suggestions
> thanks

"Hao Yuan" <toxiccool@hotmail.com> wrote in message
news:hkrf5o$4q2$1@fred.mathworks.com...
>I had the same problem, I haven't figured out any solution yet.....Hoping
>some super guy can fix it....
> It sounds like a bug definitely..
>
>
>
> "Terence Mc Cartan" <mrterencemccartan@gmail.com> wrote in message
> <ef1ba8d.-1@webx.raydaftYaTP>...
>> Hi all,
>> having trouble gettin a 'semilogy' plot. I have the command in a
>> 'for' loop to plot about 20 lines using 'hold on' also. But when the
>> plot comes out its on a linear linear scale.
>> Ill appreciate any suggestions

Post your code. Depending on which command you call first, before the HOLD,
you could get either both plots on a linear y scale or both on a log y
scale.

% both plots on a linear y scale due to HOLD ON holding the "linearness" of
the Y axis
plot(1:10, 1:10);
hold on;
% SEMILOGY can't change the held YScale property of the axes
semilogy(1:10, 100:100:1000)

% Similarly, both plots will be on a log y scale due to HOLD ON
semilogy(1:10, 100:100:1000);
hold on;
% Normally PLOT resets many axes properties, including YScale, to their
defaults
% but due to HOLD ON, it cannot
plot(1:10, 1:10)

If you want to _force_ the first example to give you a log y scale,
explicitly set the YScale property after executing that code (or even just
after executing the PLOT call.)

plot(1:10, 1:10);
set(gca, 'YScale', 'log');
hold on;
% SEMILOGY can't change the held YScale property of the axes
semilogy(1:10, 100:100:1000)

--
Steve Lord
slord@mathworks.com
comp.soft-sys.matlab (CSSM) FAQ: http://matlabwiki.mathworks.com/MATLAB_FAQ