How can I insert time from an xlsx file into Matlab and make a plot?

I am trying to read an excel file and plot the data with time on the x-axis and energy on the y-axis. The y-axis works fine but the the time is given in this format: 0.569039351851852, instead of 10:26:39. Also, I am inserting data from several xlsx files and trying to plot the information in seperate graphs, instead, figure 1 works fine but 2 and 3 are placed on top of the information from figure 1. Does anyone have a solution two my two problems?

Best.

%-----------------------------------EV_F00084--------------------------------------------------

datasetF00084 = xlsread('EV_F00084.xlsx','Sheet2','B1:C120000');

xF00084 = datasetF00084(:,1);

yF00084 = datasetF00084(:,2);

figure(1)

plot(xF00084,yF00084,'*')

%-----------------------------------EV_F00085--------------------------------------------------

datasetF00085 = xlsread('EV_F00085.xlsx','Sheet2','B1:C120000');

xF00085 = datasetF00085(:,1);

yF00085 = datasetF00085(:,2);

figure(2)

plot(xF00085,yF00085,'*')

%-----------------------------------EV_F00093--------------------------------------------------

datasetF00093 = xlsread('EV_F00093.xlsx','Sheet2','B1:C120000');

xF00093 = datasetF00093(:,1);

yF00093 = datasetF00093(:,2);

figure(3)

plot(xF00093,yF00093,'*')

[YT]

I'm not sure why the plots not working correctly. Have you tried to use hold on / hold off to see if that helps? And did try to use close all at the beginning of your script to close previous figures?

close all; %closes previous figures

%... other code

figure;
hold on;
plot(xF00085,yF00085,'*')
hold off;

figure;
hold on;
plot(xF00093,yF00093,'*')
hold off;

Maybe it's also useful if you provide one of the .xlsx files as an attachment to your question (to help you with importing the time correctly).

[Sandra Holthe]

Thanks for the tips. Unfortunately it did not work when closing and using the hold on/off commands. I attached an example of one of the excel files for the time problem.

Answer 1

[YT]

Even though I still haven't figured out your plotting issue, the importing can be solved like so

% first time;
opts = detectImportOptions('EVdata_test.xlsx');
opts.VariableNames = {'Time','EnergyStored'};
opts = setvartype(opts,'Time','duration'); %read in as duration type
opts = setvartype(opts,'EnergyStored','double');
opts.Sheet = 'Sheet1';
opts.DataRange = 'B2:C69';
T = readtable('EVdata_test.xlsx',opts);
T = [table(datestr(T{:,1},'hh:MM:SS'),'VariableNames',{'Time'}) T(:,2)];

% second time; options only need to be set once if sheet and range stays the same
T = readtable('EVdata_test2.xlsx',opts);
T = [table(datestr(T{:,1},'hh:MM:SS'),'VariableNames',{'Time'}) T(:,2)];