Logarithmic scale with a different base

Hi,

I am trying to plot a function using logaritmic scale on the x axis, with base 2.

my code is:

N = 1:10000;
M = 61;
L = N-M+1; 
ova_complex = ((N.*(log2(N)+1))./(N-M+1));
figure
stem(log2(N),ova_complex)
xlim([6 14])

the graph im getting is good, but i want to show only the integer values on the x axis(i.e. 6,7,8,9)

is there a way to do that?

thanks

Answer 1

[Star Strider]

Try this:

N = 1:10000;
M = 61;
L = N-M+1; 
ova_complex = ((N.*(log2(N)+1))./(N-M+1));
figure
stem(log2(N),ova_complex)
xlim([6 14])
xt = get(gca, 'XTick');                                 % ADD THIS LINE
xtl = fix(min(xt)):fix(max(xt));                        % ADD THIS LINE
set(gca, 'XTick',xtl)                                   % ADD THIS LINE

That should produce integer ticks and integer tick labels.

.

Answer 2

[hosein Javan]

add the following after plot

ax = gca; % current axe
ax.XTick = 6:14;

Answer 3

[Walter Roberson]

log2(x) = log(x) *log(2)

log(2) is a uniform scaling and since plots are scaled to fit available space, becomes irrelevant.

So you get the same shape if you use semilogx. And you can lie with the labels if you want. However if you are using datatips you need your approach (unless you program them to lie)

You can use xticks() to choose integer tick locations.

Answer 4

[Joshua Carmichael]

For a natural log base, try:

logspace(0, log10(exp(1)),100)

To generate a spaced set of 100 samples that start at one and terminate at e^(1).