dot Indexing is not supported for variables of this type error on a scatterplot

Im new to Matlab and cnat figure out what is wrong with this code, I literally copied someones code down word for word, I keep getting the arror but they dont. if I comment out the scatter_2 and everything below it the code works but once I add it back in the error shows up. I dont get why I can use dot indexind on the first section but not on the second.

% Step 8: Scatter plot for the correlation between Beam Length and Yield Strength
scatter(beam_data.Length, beam_data.YieldStrength, 100, "b.")
 xlabel('Beam Length (Meters)')
 ylabel('Yield Strength (Newtons')
 title('Beam Length and Strength Correlation')
hold on
 scatter_2 = scatter(total_over_stressed_beam.Length, total_over_stressed_beam.YieldStrength, 10, "red", 'filled')
 legend(scatter_2, 'Overstressed')
 hold off
 

[Steven Lord]

Immediately before running these lines of code, run this command and show us the output:

whos

More likely than not, whoever wrote the code that you copied defined their variables differently from how you've defined yours. For example, if beam_data was a struct array asking for its Length field may work (if it has such a field):

beam_data = struct('Length', 42, 'Width', 99);
beam_data.Length

ans = 42

but if it was a plain numeric array it wouldn't.

beam_data = 1:10;
beam_data.Length

Dot indexing is not supported for variables of this type.

[Henry]

whos

Name Size Bytes Class Attributes

Saftey_factor 100x1 800 double

beam_data 100x7 8137 table

over_stressed 100x1 100 logical

over_stressed_beam_total 1x1 8 double

over_stressed_beams 11x4 2133 table

percentage_over_stressed 1x1 8 double

total_over_stressed_beam 1x1 8 double

we worked together on the project so everythin else should be the same.

[Stephen23]

Please show us the complete error message. This means all of the red text.

[Henry]

Step 8: Scatter plot for the correlation between Beam Length and Yield Strength
scatter(beam_data.Length, beam_data.YieldStrength, 100, "b.")
 xlabel('Beam Length (Meters)')
 ylabel('Yield Strength (Newtons')
 title('Beam Length and Strength Correlation')
hold on
 scatter_2 =scatter(over_stressed_beam_total.Length, over_stressed_beam_total.YieldStrength, 10, "red", 'filled')
 legend(scatter_2, 'Overstressed')
hold off


Dot indexing is not supported for variables of this type.

[Walter Roberson]

over_stressed_beam_total is a double, not a struct or table. You cannot use dot indexing on a double. You need to figure out how it got to be a double instead of a struct or table

Answer 1

[BhaTTa]

Hey @Henry, I understand that you are facing error in scatter_2 plot, specifically with using dot indexing on total_over_stressed_beam, follow the below steps to troubleshoot the issue:

1. Ensure that total_over_stressed_beam is defined before you attempt to use it. It should be a structure or table with fields Length and YieldStrength.
2. Double-check the spelling of total_over_stressed_beam and its fields. MATLAB is case-sensitive, so any mismatch will lead to errors.
3. You can verify that total_over_stressed_beam is indeed a structure or table by using the whos command or class function.

[Henry]

I gave all those a try and the error still appears, could there be any other fixes?