Correct use of Semilogx

I have the following script:

clear all;close all; clc
x = 0:.01:50;
r=[.01, .05, 1];
for ri = 1:3
  [y] = HW1_4_func(x,r(ri));
  xd = y(1:50);
  deltax = .01;
  dy = diff(y)/deltax;
  subplot (3,1,ri)
  hold on
  semilogx (y,  'b');
  semilogx (dy, 'r');
  legend ('y', 'dy');
  xlabel('Time')
  ylabel('Height')
  caption = sprintf('R= .01 (plot 1), .5 (plot 2), and 1 (plot 3)');
  title(caption, 'FontSize', 10);
end
and the following function:
function [y, dy] = HW1_4_func(x,r)
y = (1+r).*exp(x) ./ (1+r.*exp((1+r)*x));

How do I change it so that when it plots, the X-axis changes to a log scale. I tried the semilogx (y, 'b') and semilogx (dy, 'r') and nothing happens. What am I doing wrong when plotting?

Answer 1

[Azzi Abdelmalek]

set(gca,'xscale','log')

[Akash Agarwal]

By doing this, will this alter the graph?

When i entered in the function, it altered the graph quite a bit.

[Azzi Abdelmalek]

This is normal, because you have changed the x scale.