Line thickness 'invalid data argument' error

Can anyone tell me why im getting an "invalid data argument" error when trying to change the line thickness. The commented out line works fine.

%plot(x,f,'r',x,fh,'b')

plot(x,f,'r','LineWidth',3,x,fh,'b','LineWidth',1)

legend('f','fh','Location','best')

Answer 1

[madhan ravi]

plot(x,f,'r','LineWidth',3)
hold on
plot(x,fh,'b','LineWidth',1)

[Calvin Williams]

Thank you!

[madhan ravi]

That's why reading documentation is encouraged therefore no guessing is needed

https://www.mathworks.com/help/matlab/ref/plot.html#btzpnds-1