plot in matlab with similar xlabels spaces-CodePudding

I have a figure in matlab, where xlabel is 2 power n values, where n is an integer and ylable includes any vector values, I need to plot those values and keep x vector to be equal spaced. What I do now is correct but small spaces in xlabel are shown when x values are small while that becomes larger with higher values of x values.

That is what I did:

M = [2, 4, 8, 16, 32, 64, 128, 256];
s1 = [104   136   168   200   232   264   296   328]; 

figure(1) 
semilogy(M, s1, 'ko-', 'LineWidth', 1); hold on;   %


grid; 
axis ([0 256 0 600])
xticks(M);

enter image description here

CodePudding user response：

One way to have evenly spaced xticks is to use a linear vector (0,1,2,3,etc...) the same length as your data. You plot your y data versus this xa (X Apparent) vector, then just modify the xticklabels to display the proper power of 2 corresponding to each point.

So for your code:

max_xa = numel(M)-1 ; % number of "x" points (-1 because we'll start at 0)
xa = 0:max_xa ;       % generate the x-apparent vector

figure
% Plot your "sl" values versus "xa"
semilogy(xa, s1, 'ko-', 'LineWidth', 1); grid on ; 
axis ([0 max_xa 0 600]) % adust limits
xticklabels(M);         % adjust X tick labels

will generate the following figure:

Note: We started the X apparent vector at 0 instead of 1 because otherwise Matlab would automatically insert a xtick at the value 0 and our xticklabels would all be offset by one position.

CodePudding user response：

Your issues will remain unless you drop some xticklabels or better use loglog to plot which retains the feature of parabolic data.

Use following lines in your code: loglog(M, s1, 'ko-', 'LineWidth', 1); hold on; %

You will get this result 1