Is it better to generate a plot from a spreadsheet or enter it directly into MatLab?

I have finished all of the Getting started with MatLab introductory lessons. but am otherwise new to MatLab. My immediate purpose in getting MatLab is to generate plots of blood glucose readings for some diabetic friends. They currently have the data in spreadsheets. They want a graph showing how changes in treatments affect their readings. Initially, each plot will be for a period of 2-4 weeks during which the medications will be static. The plot will show one line for AM readings and one for PM readings and then a trendline for each. Here's a plot from an old shareware program one of them is using. I want to do something much better than this.

I have a couple of questions:

1. Is it better to have MatLab extract the data from their spreadsheets or should we re-enter it directly into MatLab?
2. Later, I will want to make a "summary" plot showing the averages of each period and possibly a trendline.
3. Where is the best place for me to go to get started on this? Is there a tutorial that is focused more or less on this?
4. I'd appreciate any other or suggestions.

Thanks

PS: How to I shrink the plot above so it doesn't dominate the post?

[Walter Roberson]

If the data is in regular format, then it is usually better to read from the spreadsheets.

If the data is not in regular format, then sometimes it can be worth making it regular

Reading from spreadsheets is slower than built-in data, but the extra time for well-formatted spreadsheets is small compared to the amount of time it would take to re-enter the data.

[Cynthia Moore]

I'm not sure what you mean by "regular". The data is in a spreadsheet, so it's rows and columns. There's a Date column, an AM Reading column, and a PM Reading column.

[per isakson]

In the menu you use to add the image there is a drop-down-menu Display Settings.

I changed size of your image to 50%

[Walter Roberson]

Humans are often bad about not putting data into consistent columns or putting in extra rows or putting in text explanations in fields that should be just numbers, or not using consistent date formats.

[Cynthia Moore]

OK, thanks.

That adjustment can only be made when I add the image? Once it's added, is there a way to change it?

It looks like you did change it, right? Thanks

[Walter Roberson]

If you go into the editor and click on the already-added image, and then click on the picture-frame tool in the toolbar, then you can edit the percentage.

Answer 1

[Steven Lord]

There's no tutorial that covers creating a plot specifically like that, but there are tutorials for some of the pieces that you'll probably need to combine to create such a plot. The "Data Import and Analysis" section of the Examples list should contain some examples that will help you import your data into MATLAB. The "Graphics" section should contain some examples (Combine Multiple Plots, perhaps) and the "Mathematics" section has a few related to curve fitting (to fit your trend lines.)

In addition, if you search the Support website for phrases that describe each step ("import data from spreadsheet" for example) you may find additional examples and videos that will be helpful.

[Cynthia Moore]

OK, thanks