Extracting data from .mat file

Hi,

I need to extract illumination and time data from a .mat file and calculate corresponding power output for a particular solar panel. Can anyone help me regarding this ?

Thanks in advance.

[Rik]

If you have trouble with Matlab basics you may consider doing the Onramp tutorial (which is provided for free by Mathworks).

doc load

Answer 1

[Star Strider]

Use the load function, and specifically, Load List of Variables into Structure Array. The structure array then allows selection of specific variables within the file to import into the workspace.

[Raisa Sharmin]

I have 27232842x1 double data in one column of the file, having problem with the sorting and doing the calculations

[Star Strider]

I am not certain what the problem is, what the data are, or what you want to do with the data in the file.

I can provide more help with a few more details.

[Raisa Sharmin]

It is like, I got 3years of solar illumination data of a particular solar panel, now I need to calculate the output power. I need to seperate the data monthwise, and calculate the output power for a single day.

[Star Strider]

It would appear that you have a datetime variable with the data as a dependent variable.

There are several ways to deal with it, including converting it to a timetable and using the retime function, using the groupsummary function, and other approaches. Read the documentation for those and related functions (linked to in the documentation pages for those and other related functions). Start with the Timetables documentation and go from there.

[Raisa Sharmin]

thanks for the suggestion, I am going through it.. would comment again if I need more help.

[Star Strider]

As always, my pleasure!

You should be able to do it without much effort, if you already have a reasonably robust knowledge of MATLAB.

I will help as I can.

[Raisa Sharmin]

I do not have that much knowledge actually, I am just a new learner.. Thank you :)

[Raisa Sharmin]

Hi, im using the table2timetable function, my matlab version is R2020_b, and was following this video, but I cannot name the loaded file like this.

https://se.mathworks.com/videos/managing-time-stamped-tabular-data-with-timetable-120888.html

[Star Strider]

I do not understand thke problem you are having.

[Raisa Sharmin]

Hi, I am sharing the screenshot

[Star Strider]

As I mentioned earlier, load ‘Alison_intensity_data.mat’ in to a structure. You can then determine what is has in it, and extract it.

D = load('Alison_intensity_data.mat');
time = D.time;                                                      % Try Something Like This To Extract It

Apparently, ‘time’ is not already a table, so perhaps using the timetable function instead will be appropriate.

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