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John
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How do I plot lines with different line widths?

Asked by John
on 22 Sep 2011
Latest activity Answered by MASTER WHOS on 14 Feb 2019
Hi,
I want to do:
plot(x1,y1,x2,y2,'LineWidth',8)
but the linewidth propery ends up applying to both lines. Do I have to use two plot functions with a hold on command to have line1 a different width than line2? Thanks.

  2 Comments

Try writing like this plot(x1,y1,'Linewidth',6,x2,y2,'Linewidth',8)

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4 Answers

Answer by Fangjun Jiang on 22 Sep 2011
Edited by MathWorks Support Team on 8 Nov 2018
 Accepted Answer

To plot two lines with different line widths, you can use either of these approaches.
1. Return the two “Line” objects as an output argument from the “plot” function and then set the “LineWidth” property for each.
p = plot(x1,y1,x2,y2)
p(1).LineWidth = 5;
p(2).LineWidth = 10;
2. Use the “hold on” command to plot the two lines separately. Specify the line width by setting the “LineWidth” property a name-value pair.
plot(x1,y1,'LineWidth',5)
hold on
plot(x2,y2,'LineWidth',10)
hold off

  2 Comments

Just FYI, there is an "official" syntax for setting a property to different values on different objects. However, it's really ugly, and doesn't work everywhere. For example, I don't think that the plot function accepts this form.
It looks like this:
h = plot(x1,y1,x2,y2);
set(h,{'LineWidth'},{5;10})
The property name and property value need to each be a cell array, and the shape of the value cell array has to match the shape of the handle cell array.
That said, you're really better off with 2 calls to set in this case.

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Answer by Wayne King
on 22 Sep 2011

Hi: You can use handles.
h = plot(x1,y1,x2,y2);
set(h(1),'linewidth',1);
set(h(2),'linewidth',2);

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Answer by Hari Desanur on 15 Nov 2016
Edited by Hari Desanur on 15 Nov 2016

The line width for a particular line can be set using line object handles. For example -
l = plot(x1,y1,x2,y2);
l(1).LineWidth = 3; % set line width of 3 for the first line (x1,y1)
l(2).LineWidth = 6;

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Answer by MASTER WHOS on 14 Feb 2019

1-What might be the problem? 2-What does linewidth property mean? 3-What to do?
[I am using matlab R2016b]
When I want to plot line with color and certain width, I recceive an error:
THE COMMAND
plot(SNR_db,Pd_NSP_cat_mean(:,2),'b','LineWidth',2.5)
THE ERROR:
Error using plot
There is no LineWidth property on the Line class.
Error in PROJECTION_BASED_SHARING (line 76)
plot(SNR_db ,Pd_NSP_cat_mean(:,1),'g','LineWidth ',2.5)

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