I am developing a GUI in Matlab and I added a uiimage to receive info, so that.

Davide Coluzzi (17 days 23 hours ago): Hello, I have just found out this website and the book, they are great! Many thanks for this.

Next week, I will explain how looking under hgsave‘s hood leads to useful functions and to an interesting insight about Matlab’s future. Have you used the FIG/MAT feature for any useful functionality? If so, please do share your experience in a comment. ApplicationData is such a hidden handle, which is widely used as a substitute for any handle’s UserData property (the built-in setappdata and getappdata functions are simply wrappers for accessing this property using standard set and get functions). Secondly, we see hidden/undocumented properties of the stored objects (for example, the lineseries’ XDataJitter and ObeyXDataMode properties). Basically, it indicates that the structure holds a Matlab 7 figure.

We see a couple of interesting things in this simple example:įirst, note that the top-level structure node is called “hgS_070000” – we’ll dig into this next week. HgS_070000: % a Matlab 7 figure % Investigate the figure data This is hinted in several places, for example in hgsave‘s doc page, and in the MAT-file preferences panel: It seems that a FIG file is simply a hierarchical structure of all the non-default properties of the stored figure and its descendant handles, all this stored within a simple MAT file. Here’s where the undocumented stuff enters:

The answer: FIGs are simply MATs in disguise We often just need to extract a sub-set of the stored information (for example, the plot values), without having to display the figure. This is bad in terms of performance and memory, especially for heavily-laden GUI figures, not to mention the fact that sometimes we do not want to display the GUI at all.

The point is that in order to re-load the stored data, we need to use hgload, which has a nasty side-effect of actually displaying the stored figure. In all cases, the data is stored in a *.FIG file (the FIG extension can actually be changed, but I really don’t see why). In Matlab, saving is done interactively (via the figure’s File/Save menu option or via the figure’s Save toolbar button), or programmatically (via the hgsave function). In data-processing applications, we often present data in graphs that can then be manipulated and saved for later use. The need: load a FIG without displaying it The answer to this question is easy, but I wish to use the opportunity to show how this can be useful in Matlab applications. A short while ago, a StackOverflow user asked how to extract data from FIG files in Matlab.

Open fig file without matlab functions