I want to adjust the x-axis according to the histogram distribution.

A simple example is shown in the following image.

It does not mean histogram smoothing.

Answer 1

[Star Strider]

I am not certain what you want to do.

Try this:

x = 0:50;                               % Create Data
y = exp(-0.1*x);                        % Create Data

mask = y >= 0.1;                        % Select Data Greater Than A Threshold Value

figure
subplot(2,1,1)
bar(x, y)
subplot(2,1,2)
bar(x(mask), y(mask))

It selects values for ‘y’ greater than a threshold value, then plots only those values in the second subplot. Note that you must use the bar plot for this, so you will need to use histcounts or related functions first.

[Jae Min Lee]

Thanks. However i do not know why the threshold is 0.1.

[Star Strider]

You can set the threshold to be anything you want. The value of the threshold and how you calculate it depends on your data.

For example, using histcounts (link):

x = 0:50;                                   % Create Data
data = exp(-0.1*x);                         % Create Data

nbins = 30;
[N,edges] = histcounts(data,nbins);         % Histogram
mask = N >= 0.1*max(N);                     % Define Conditions Based On Histogram Frequencies

ctrs = edges(1:end-1) + mean(diff(edges));  % Calculate Centres

figure
subplot(2,1,1)
bar(ctrs, N)
subplot(2,1,2)
bar(ctrs(mask), N(mask))

Without your data, I cannot be more specific.

Answer 2

[Image Analyst]

Maybe you want

xlim([0, 0.02]); % Make the x axis go from 0 to 0.02.

[Image Analyst]

If xlim() didn't work, say why not, and attach your data.

http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer