How does a line plot handle data larger than the axes size?

If I plot a time series with 27,000 samples in an axes that is 900 pixels wide (i.e. the x-axis). how does the plot function fit the data in the plot? Because there are 30 samples per pixels, how does the plot function determine what to plot for each pixel? Does it do straight decimation? Does it peak pick? I tried a few examples, and it appears that the plot function peak picks. I want to verify this, and also ask if this is something that the user can select.

Thanks times a million,

Bill

Answer 1

[Jan]

This was answered some years ago: https://www.mathworks.com/matlabcentral/answers/252979-increase-the-plotting-performance-in-the-matlab-level-drawmode-optimizing-rendering-down-sampling#comment_321750

See also:

• https://blogs.mathworks.com/graphics/category/performance/
• https://blogs.mathworks.com/graphics/2015/06/09/object-creation-performance/

[Otis]

Wow ... A whole new (to me) area of science ... how to reduce a line of N points down to M points (N >> M) so a plot looks "correct", with minimal loss of information to the observer. Fascinating.

(Quick follow up question: Are there similar approaches for dealing with the same problem for 2D image plots where the data size MxN is larger than the axes size mxn?)

Thanks so much for your response,

Bill