Please I have a code but it keep saying Invalid expression. When calling a function or indexing a variable, use parentheses. Otherwise, check for mismatched delimiters.

DETEnergyDetector(:,11) = DETEnergyDetector(:,11)/max(DETEnergyDetector(:,11));
figure('visible','off');
errorbar(DETEnergyDetectorE(:,3), DETEnergyDetector(:,11), ...
2*DETEnergyDetector(:,11).*DETEnergyDetector(:,12);'k.');

Answer 1

[Geoff Hayes]

@Sedulous12 - there is a semi-colon instead of (perphaps) a comma:

2*DETEnergyDetector(:,11).*DETEnergyDetector(:,12);'k.');  % <--- semi-colon before 'k.'

Try changing this line to

errorbar(DETEnergyDetectorE(:,3), DETEnergyDetector(:,11), ...
         2*DETEnergyDetector(:,11).*DETEnergyDetector(:,12), 'k.');

as that might remove the error.

[Sedulous12]

Thanks Geoff Hayes, it did remove the error.