Change x-axis grid lines

Hello,

In my MWE below, I wanted to know how to add minor grid lines of 0.001 to the x-axis?

Here is my code:

% Select file
clear;
clc;
[FileName,PathName] = uigetfile('*.txt','Select data file');
fid = fopen( strcat(PathName,FileName) ,'rt' );

% Read the file and store into matrix v
i = 0;
v = [0 0];
while feof(fid) == 0
    buffer = fscanf(fid, '%f', 2);
    buffer = buffer';
    if i == 0;
        v = buffer;
    else
        v = vertcat(v,buffer);
    end
    i = i + 1;
end

% Frequency vector
x = v(:,1);
y = v(:,2);

plot(x,y); 
grid on;
title('Spectrum @ 380.025MHz');
xlabel('Frequency (MHz)'); ylabel('Amplitude');
return

[Chad Greene]

A note: Get into the habit of using k as a counter because in some cases Matlab will think you mean the sqrt(-1) when you use i or j. You can usually overwrite i and j safely, but when it causes problems it can be tough to debug.

Answer 1

[Chad Greene]

You can turn on minor ticks by

set(gca,'XMinorTick','on')

and/or

set(gca,'XMinorGrid','on')

but exact values of the minor grid are hard to control. You may simply plot thin vertical lines at the values you desire by

plot(repmat(380.01:0.001:380.035,2,1),repmat([-140 0]',1,26),':','linewidth',0.5,'color',[.5 .5 .5])
hold on
plot(x,y,'b','linewidth',2)

I made the grid lines above quite thin and subtle because grids are only useful to viewers who are inspecting a plot with a straight edge. The muted grid is good enough for the detail-oriented viewer to see. For anyone who is glancing at the plot to get the big picture, grids are nothing but clutter, IMO.