{"id":3126,"date":"2019-02-22T11:12:57","date_gmt":"2019-02-22T16:12:57","guid":{"rendered":"https:\/\/blogs.mathworks.com\/steve\/?p=3126"},"modified":"2019-11-01T22:34:21","modified_gmt":"2019-11-02T02:34:21","slug":"making-your-plot-lines-thicker","status":"publish","type":"post","link":"https:\/\/blogs.mathworks.com\/steve\/2019\/02\/22\/making-your-plot-lines-thicker\/","title":{"rendered":"Making your plot lines thicker"},"content":{"rendered":"

Today's blog post is dedicated to everyone whose eyes aren't as young as they used to be.<\/p>

In last week's blog post on pursuit curves, I showed this figure:<\/p>

\"\" <\/p>

If you ran my code exactly as I posted it, though, you probably wouldn't see exactly the same thing. You would see something like this instead:<\/p>

\"\" <\/p>

Do you see the difference? Exactly what you see will vary depending on your computer and your display resolution, but the original image from my blog post has thicker colored lines.<\/p>

That's because I don't use the default line thickness for my plots.<\/p>

Let me show you what I mean. Here's a basic example of plot<\/tt> from the MATLAB documentation:<\/p>

x = linspace(-2*pi,2*pi);\r\ny1 = sin(x);\r\ny2 = cos(x);\r\n\r\nfigure\r\nplot(x,y1,x,y2)\r\n<\/pre>\"\" 
The plot above uses the default MATLAB line width of 0.5 points. Here's where I have to wave my hands a little. Because of the way the figure above was captured for display in your browser, the lines probably appear a little thicker than 0.5 points. On a high resolution display, however, the plotted lines are pretty close to 0.5 points thick.<\/p>
And, to my eyes, that's too thin to see the colors clearly.<\/p>
So, I like to plot thicker lines, roughly 1.5-2.0 points. You can do that in each call to plot<\/tt> by using the LineWidth<\/tt> parameter, like this:<\/p>
plot(x,y1,x,y2,'LineWidth'<\/span>,2.0)\r\n<\/pre>\"\" 
But then you have to remember to add the LineWidth<\/tt> parameter all the time. It turns out that there's a way to get MATLAB to draw all plotted lines thicker by default. Here it is:<\/p>
set(groot,'defaultLineLineWidth'<\/span>,2.0)\r\n<\/pre>
This odd-looking line of code sets the default LineWidth<\/tt> property for line<\/tt> objects to 2.0. For a full explanation of the MATLAB system for setting default graphics object properties, see Default Property Values<\/a> in the MATLAB documentation.<\/p>\r\n\r\n
\r\n\r\nUpdate: Using a thicker line width might only work well for high-DPI monitors. Blog reader Gang Yao pointed out that using 2-pt. lines can make markers indistinct, and I can confirm that observation when not using a high-DPI monitor. After some additional experimentation, I found that using 1.5-pt. lines on a high-DPI monitor works a little better.\r\n<\/em>\r\n<\/p>\r\n\r\n
This default setting does not persist between MATLAB sessions, though. If you want to do this for each MATLAB session, put the call to set<\/tt> into a file called startup.m<\/tt> that is located in your user path<\/i> folder. Run the userpath<\/tt> function to see where that is. Here's mine:<\/p>
userpath\r\n<\/pre>
\r\nans =\r\n\r\n    '\/Users\/steve\/OneDrive - MathWorks\/MATLAB'\r\n\r\n<\/pre>
You can also use the userpath<\/tt> function to change your user path location, if you don't like the default location chosen by MATLAB. (That's what I did.)<\/p>
For more information, see the function reference pages for startup<\/tt><\/a> and userpath<\/tt><\/a>.<\/p>
Do you like thicker plotted lines too? Or is it just me?<\/p>