I have 3-hours data interval for 1 day data. How do i plot a bar graph in matlab?

Question

MUHAMMAD 2022-12-16

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1879477-i-have-3-hours-data-interval-for-1-day-data-how-do-i-plot-a-bar-graph-in-matlab

评论： Walter Roberson 2023-1-2

Kp20150516.txt

Help, I need to plot a bar/histogram graph exactly like this website https://www.spaceweatherlive.com/en/archive/2012/05/12/kp.html using Matlab coding.

For briefing, we assume the file name is Kp Value. The Kp Value file will consist of 30 days of 3-hours interval data. For example, 0-3 UT, 3-6 UT, 6-9 UT, ..., 21-24 UT. Therefore, one (1) day data should have 8 bar in one graph. You get what i mean? (You can refer at the link as well).

So now, i want to add 10 days data in one graph where in my task, my date is from 2015-05-12 until 2015-05-22 (exactly ten (10) days). Below i attached the Kp Value file (Kp20150516.txt) for one month of 05-2015 to ploting the bar/histogram bar which I just want to grab the 10 days data (which consists of 3-hours interval data) from 2015-05-12 until 2015-05-22 as i mentioned before from the file name Kp20150516.txt.

This is my idea but it shows the whole 30 days data. It get messy.

Kp = load('Kp20150516.txt');
date_h=find(and(UT1h>=datenum(2015,05,12,0,0,0),UT1h<datenum(2015,05,21,24,0,0)));
bar(UT1h(date_h),Kp(:,8),0.8,'stacked'); %Kp(:,8) column 8 is the exactly value of Kp.
datetick('x','dd','keeplimits')
ylabel('Kp Index');
xlabel('Days');

This is the graph that i get messy.

Since i want to combine 2 plot in one graph, the value should be 240x1 double and each days must have only 8 bars. Otherwise, it shows error like this

Error using plot
Vectors must be the same length.
Error in Lemah (line 57)
plot(UT1h(date_h),Kp(:,8),'LineWidth',1.2)

Thank you!

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Adam Danz 2022-12-20

编辑：Adam Danz 2022-12-20

The mat file download is not a mat file and it is nearly 1gig.

I tried treating it as a zip file but that also did not work.

Walter Roberson 2023-1-2

The attached file is about 15 kilobytes.

The sharepoint file (not attached) is large, but when I click through the download procedure on the linked page, and save to a local drive, then MATLAB is able to open the file as a .mat file.

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Answer 1

Suvansh Arora 2022-12-20

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1879477-i-have-3-hours-data-interval-for-1-day-data-how-do-i-plot-a-bar-graph-in-matlab#answer_1132032

To resolve the issue mentioned, follow the procedure mentioned below:

In order to plot different bar graphs for different days of month, you may choose to save bar graphs using ‘savefig’. Legend and figure name will be helpful in identifying the day for which the bar graph is plotted.

for i = 1:8:size(date_h(:))

bar(Kp(i:i+7,8),0.8,'stacked'); %Kp(:,8) column 8 is the exactly value of Kp.

%datetick('x','dd','keeplimits')

ylabel('Kp Index');

xlabel('Hours');