What is a cell array Edit.A cell is a flexible type of variable that can hold any type of variable.A cell array is simply an array of those cells.Search and download open source project source codes from CodeForge.Background. JAMA is a basic linear algebra package for Java.It provides userlevel classes for constructing and manipulating real, dense matrices.Solving a Matlab hang problem.Closing a modal dialog may hang Matlab Every now and then I stumble on a case where Matlab hangs, becomes totally unresponsive and requires me to kill the Matlab process externally via the task manager.The undocumented solution is frustratingly simple see below, and yet I keep forgetting it.The last time this happened was only two days ago, and by pure coincidence a readers comment yesterday happened on the same page where I explained the problem and solution. Best Western Rewards more. So I am taking this opportunity to explain the problem and the workaround, before my senility takes over and I forget again The symptom Matlab hangs.The symptom is easily detectable youre happily working on your favorite Matlab GUI application, when suddenly some modal dialog window appears perhaps a msgbox, a questdlg or an inputdlg.After clicking the lt OK button, Matlab seems to freeze, and any attempt to close the window or to stop the GUI fails.Matlab Joe' title='Matlab Joe' />Spiralling global temperatures.Click for full size animated version.The animated spiral presents global temperature change in a visually appealing and.Forget about Ctrl C it simply hangs.The only workaround is to open the operating systems task manager and kill the Matlab process.There are several odd things here Firstly, the task manager shows that the Matlab process is not consuming any CPU.Secondly, the hang does not appear consistently sometimes it does, other times not, making debugging extremely difficult.Moreover, when we debug the code, stepping through the source code lines one at a time, everything seems to behave perfectly normal it is only when running the program in continuous mode that the hang appears.The solution adding drawnow.The underlying reason for the hang appears to be that when we close the modal dialog window, it is sometimes not yet fully destroyed when we proceed with our program.It is my belief that this creates race conditions which in some cases cause a deadlock between Matlabs Main Thread and Javas Event Dispatch Thread EDT.Matlab EDT synchronization problems are often time dependent, which explains why the hang sometimes occurs and sometimes not.While debugging EDT synchronization problems is notoriously difficult, the solution is often extremely simple Just add a combination of drawnow and a short pause uiwaitmsgbox.Matlab hang. answer questdlg.Matlab hangswitch answer.Adding drawnow and pause forces Matlab to flush EDTs event queue, thereby ensuring synchronization before proceeding with the Matlab code.This is actually quite important when integrating Java GUI components in Matlab figures especially before R2.Object. EDT became available.In the particular case of the Matlab dialog hang, drawnow is probably sufficient and pause is unnecessary.As noted by Bill York Math.Works dev team leader who is responsible for such stuff here, drawnow is similar but not exactly the same as pause.I often use both of them, since I discovered via trial and error that in the general case of EDT related timing issues, different situations respond better to either of them, and I never remember which one to use to ensure proper rendering.So the drawnowpause line appears very often in my code, quite possibly even in places where they are not strictly needed.The actual needed value of the pause may vary, depending on GUI complexity and CPU powerload, but 0.In rare cases I needed to go as high as 0.How to Calculate Slope From Data Matlab.The MATLAB software program from Mathworks is an incredibly handy mathematics and engineering tool capable of performing advanced calculations and simulations.One of its most useful functions is carrying out many different types of data analysis.A common type of analysis is calculating the best fit slope from a group of data points.MATLABs polyfit functions performs this job nicely by fitting a polynomial line to the data points using least squares calculations.If the user chooses the degree of the polynomial line to be 1, the result is the linear best fit slope of the data.Step. Define a relationship between an independent and dependent variable.The data may come from experimental data or you may define the relationship directly.For example, experimental data may be a measure of magnitude versus time.In this case, list t may consist of the numbers 1 2 3 4 5 and list m may contain the values 2 4 6 8 1.Step. Decide whether the desired polynomial curve to fit the data should be of degree 1 linear, 2 quadratic or higher.Step. Use the polyfit function in the form polyfitindependent variable, dependent variable, polynomial degree.In our example, and desiring a linear slope, type polyfitt,m,1 and MATLAB will output the following 2.Step. Note that the 2 in the output of the previous step is the linear best fit slope of the data provided.
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