Asked by Sarah
on 18 Apr 2012

Hey guys,

I am trying to plot a vertical line in matlab. i need to be able to change its thickness and its color. I will be plotting several vertical lines. I need to plot it at a specific point on the x-axis, and it needs to extend vertically in both directions.

Here is what I have so far:

figure; clf; plot(TimeNum,AirTemp1,'k.','LineWidth',1.2); datetick('x','HH:MM:SS'); xlabel('Time'); ylabel('Temp. (deg-C)'); grid on; line([x(668) x(668)],[-3.2 -2.8]); set(gca,'YLim',[-3.2 -2.8])

I dont know why, but my line doesn't show up. Any help would be much appreciated!

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Answer by Geoff
on 18 Apr 2012

As the error says, you don't have a variable called `x` and so you can't ask for the 668th element.

You might mean this:

line([668 668],[-3.2 -2.8]);

Answer by Walter Roberson
on 18 Apr 2012

Your code

line([x(668) x(668)],[-3.2 -2.8]);

is fine. Just add appropriate options like 'LineWidth' and 'Color'.

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## 1 Comment

## Sarah (view profile)

Direct link to this comment:http://www.mathworks.com/matlabcentral/answers/35824#comment_74307

oh sorry, i almost forgot, here is the error notice:

??? Undefined function or method 'x' for input arguments of type

'double'.