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

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.

Maybe you want

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