![matlab plot legend matlab plot legend](https://i.stack.imgur.com/E2NgN.png)
But when performance is important, we can still display a legend without its usual performance cost.
#Matlab plot legend how to
Sometimes we actually wish for this dynamic effect (last year I explained how to use the legend’s undocumented -DynamicLegend feature for even greater dynamic control). Of course, it prevents the legend from being dynamically updated. Now this is much much better – a 76% performance boost compared to the original plot (i.e., 4 times faster!). > setappdata(gca,'LegendColorbarReclaimSpace',1) > setappdata(gca,'LegendColorbarManualSpace',1) > setappdata ( gca, 'LegendColorbarReclaimSpace', 1 ) > setappdata ( gca, 'LegendColorbarManualSpace', 1 ) > set ( gca, 'LegendColorbarListeners', )
#Matlab plot legend code
Looking inside the legend code (specifically, the legendcolorbarlayout function), we detect several short-circuits that we can use to make the legend static and prevent recomputation: Running the profiler on the code above we see that much of the time is spent recomputing the legend. Hack #1 gave us a 22% performance boost, but we can do much better. But if performance is important, we now know that we have this tool to improve it.
#Matlab plot legend manual
Of course, setting manual limits prevents the axes limits from growing and shrinking automatically with the data, which can actually be a very useful feature sometimes. Note that this trick is the basis for the performance improvement that occurs when using the plot’s undocumented set of LimInclude properties. > for idx = 1 : length(x) plot(x(idx),y(idx)) drawnow end > for idx = 1 : length (x ) plot (x (idx ),y (idx ) ) drawnow end > plot (x ( 1 ),y ( 1 ) ) hold on legend data Let us simulate the situation by adding 500 data points to a plot, one at a time: If instead we manually set the axes limits to the requested range, Matlab skips these checks, enabling much faster plotting performance. This computation-intensive task is done for any limit that is set to ‘Auto’ mode, which is the default axes limits mode. Whenever Matlab updates plot data, it checks whether any modification needs to be done to any of its limits. Even in such cases, we can still find important performance tricks, such as these: Performance hack #1: manual limits Unfortunately, sometimes (as in my specific case above) all these cannot help. I begin by stating the obvious: whenever possible, try to vectorize your code, preallocate the data and other performance-improving techniques suggested by Matlab. Today, I want to share a couple of very simple undocumented hacks that significantly improve plotting performance and fixed my problem. Matlab’s standard plotting functions simply could not keep up with the rate of data change. Check this link for more information about the text() function.I recently consulted to a client who wanted to display an interactive plot with numerous data points that kept updating in real-time. You can also put multiple strings in the same box by making a cell array of the strings. Now let’s add a blue line before the text and a black box around the text and the line. For example, let’s plot a cosine wave and put some text on it with font size 18 and red color. You can also change the properties of the text like the font size using the FontSize property and the color using the Color property etc.
![matlab plot legend matlab plot legend](https://in.mathworks.com/help/examples/stats/win64/ScatterPlotWithMultipleGroupingVariablesAndAllOptionsExample_01.png)
If you give the coordinates which don’t lie on the plot, you won’t be able to see the text. Simply plot the variable and then select the coordinates from the plot and then use the text() function to place the text on the selected coordinates. You need to pass the x and y coordinate on which you want to place the text. We can also use the text() function to add text to the plot. Add Custom Legends Using the text() Function in MATLAB Check this link for more information about the legend() function. You can add as many legends as you want on a figure you just have to add more plots with undefined values on the same figure. In the above code, we added three legends on a cosine wave plot, and you can see they are not related to the plot. For example, let’s add custom legends to a cosine wave plot. You will not see the plots because their values are undefined, but you will see the legends. So to add custom legends that do not have any relation with the graph, you have to add more plots on the figure with undefined values, and then you can add more legends. If you try to add more than one legend using this function, MATLAB will give an error. But the problem is it only adds one legend on one plot. The legend() function is used to add legends to a plot in MATLAB. Add Custom Legends Using the legend() Function in MATLAB In this tutorial, we will discuss how to add custom legends to the plot using the legend() and text() function in MATLAB. Add Custom Legends Using the text() Function in MATLAB.Add Custom Legends Using the legend() Function in MATLAB.