How do I control the xticks if x is a long imported excel column (Time Format: HH:MM:SS)?

How can I show out of the 1700 values of a time column (in HH:MM:SS format), only a couple of them in the x axis? Do I have to change the time format into a double value to define how it should be in the x axis?

[Shae Morgan]

Try this out: Since I didn't have your variable class, I had to assume you're dealing with time-stamps here. This works for those:

t1 = datetime(2020,8,12,13,11,24); %start time
t2 = datetime(2020,8,12,13,18,36); %end time
time5 = t1:seconds:t2; %create a vector of time points from the start time to the end time
v5 = randn(size(time5)); %create random y-axis data
plot(time5,v5) %plot data
hold on; %hold the current figure so the first plot doesn't erase when you do the 2nd plot
avg5 = mean(v5); %the average value of v5
x2= [time5(1) time5(end)]; %x-values for the average line
plot(x2,[avg5 avg5], 'y-', 'LineWidth',2); %plot the avg line
title('value 5 by time plot') %title the plot
legend('Raw data','Average line') %add a legend to differentiate the two data sources
ax = gca; %get current axis
x_step_size=100; %step size between labels in seconds
ax.XAxis.TickValues = t1:seconds(x_step_size):t2; %adjust the tick values to the correct spacing

[Shae Morgan]

[Shae Morgan]

if this answers your question, please accept

Answer 1

[Shae Morgan]

Try this out: Since I didn't have your variable class, I had to assume you're dealing with time-stamps here. This works for those:

    t1 = datetime(2020,8,12,13,11,24); %start time
    t2 = datetime(2020,8,12,13,18,36); %end time
    time5 = t1:seconds:t2; %create a vector of time points from the start time to the end time
    v5 = randn(size(time5)); %create random y-axis data
    plot(time5,v5) %plot data
    hold on; %hold the current figure so the first plot doesn't erase when you do the 2nd plot
    avg5 = mean(v5); %the average value of v5
    x2= [time5(1) time5(end)]; %x-values for the average line
    plot(x2,[avg5 avg5], 'y-', 'LineWidth',2); %plot the avg line
    title('value 5 by time plot') %title the plot
    legend('Raw data','Average line') %add a legend to differentiate the two data sources
    ax = gca; %get current axis
    x_step_size=100; %step size between labels in seconds
    ax.XAxis.TickValues = t1:seconds(x_step_size):t2; %adjust the tick values to the correct spacing

Answer 2

[Madhav Thakker]

Hi

You can use xtickformat which can match the excel sheet format. You can use xticksto specify different values on the x-axis. I am attaching a MATLAB code snippet that does the same.

t = 0:seconds(30):minutes(3);

y = rand(1,7);

plot(t,y)

xticks([t(1) t(4) t(6)])

xtickformat('hh:mm:ss')

Refer https://in.mathworks.com/help/matlab/ref/xtickformat.html for more information.

Hope this helps.