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Dynamical System Viewer

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Dynamical System Viewer

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15 Mar 2013 (Updated )

GUI that plots dynamical system flow fields (and more) with sliders for adjusting parameters.

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Description

sysViewer Dynamical system graphical interface.
    h = sysViewer(oPar, cPar, fcn, typ) builds a GUI for viewing the
    effects of parameter changes on a one- or two-dimensional dynamical
    system.
 
    oPar and cPar are two-column cell arrays that define the order
    parameter and control parameter(s), respectively. The first column
    contains parameter names (strings to be typeset in latex). The second
    column contains 1x2 vectors of parameter's range. This vector defines
    plot axes limits for the order parameter and slider limits for the
    control parameters.
 
    The system is defined by the function handle fcn. For one-dimensional
    systems, this should be a function with two inputs and one output. The
    first input is system state, which will be a scalar in a one-
    dimensional system. The second input is a vector of control parameter
    values. The output of fcn can be either the rate of change of the order
    parameter (in which case fcn is the flow equation), or the system
    potential (in which case fcn is the potential function). Which function
    is supplied can be indicated by the last input typ, one of the strings
    'flow' or 'potential'. If typ is empty or omitted, 'flow' is the
    default.
 
    For two-dimensional systems defined with a flow, fcn should be a cell
    array containing two function handles, each outputting the rate of
    change along one dimension. Each function should take three inputs; the
    first two are scalar values of the order parameters, the third is a
    vector of control parameters. For two-dimensional systems defined with
    a potential, fcn should take inputs as above and output a scalar.
 
    The output h is a struct containing handles to the graphics objects in
    the GUI. Intended only for advanced tweaking or troubleshooting.
 
    sysViewer(..., defs) initializes the parameter sliders with the default
    values in vector defs.
 
    sysViewer(..., 'vectorize') speeds up computation for functions that
    cannot be evaluated with a vector. In fact, any number of trailing
    arguments will be passed to chebfun. See CHEBFUN for more options
    (CHEBFUN2 and CHEBFUN2V for two-dimensional options).
 
  --------
  Examples:
    ------
    One-dimensional
    ---
    sysViewer({'\phi' [-pi pi]}, ...
              {'b/a' [0 1]; '\Delta\omega' [-2 2]}, ...
              @(x,c) c(2)*x-cos(x)-c(1)*cos(2*x), ...
              'potential');
 
    sysViewer({'\phi' [-pi pi]}, ...
              {'b/a' [0 1]; '\Delta\omega' [-2 2]}, ...
              @(x,c) c(2)-sin(x)-2*c(1)*sin(2*x), ...
              'flow');
 
    sysViewer({'\phi' [-pi pi]}, ...
              {'b/a' [0 1]; '\Delta\omega' [-2 2]; 'c' [0 .5]; 'd' [0 .5]}, ...
              @(x,c) c(2)*x-cos(x)-c(1)*cos(2*x)+c(3)*sin(x)+c(4)*sin(2*x), ...
              'potential');
 
    sysViewer({'\phi' [-pi pi]}, ...
              {'b/a' [0 1]; '\Delta\omega' [-2 2]; 'c' [0 .5]; 'd' [0 .5]}, ...
              @(x,c) c(2)-sin(x)-2*c(1)*sin(2*x)+c(3)*cos(x)+2*c(4)*cos(2*x), ...
              'flow');
    ------
    Two-dimensional
    ---
    sysViewer('x' [-5 5]; '\dot{x}' [-5 5]}, ...
              [{'\alpha'; '\beta'; '\delta'} repmat({[-5 5]}, 3, 1)], ...
              {@(x,dx,r) dx, @(x,dx,r) -r(1).*x.^3 - r(2).*x - r(3).*dx}, ...
              'flow')
 
 --------
  Dependencies (if missing, user will be prompted to download and install):
    GUI Layout Toolbox
    sliderPanel
    uibutton
    Chebfun:
    - Stable version (one-dimensional systems only)
    - Alpha release (required for viewing two-dimensional systems)
    (as of March 14 2013)

Acknowledgements

Uibutton: Gui Pushbuttons With Better Labels, Slider Panel, Chebfun V4, Gui Layout Toolbox, and Require Fex Package inspired this file.

Required Products MATLAB
MATLAB release MATLAB 8.0 (R2012b)
Other requirements chebfun2 (http://www2.maths.ox.ac.uk/chebfun/chebfun2/)
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Comments and Ratings (3)
17 Jan 2014 Henry Harrison

Adam, thanks for the feedback.

Yep, it was working through Strogatz (and my professor's terrible Matlab visualizations) that inspired me to write this.

I had removed the toolbars at one point but I added them back in for some reason. Don't remember what my reason was, if I can remember which tool I needed maybe I'll delete the rest but leave that.

I'll definitely go with OOP next time, especially after learning OOP design principles for Python. It definitely looks easier for Matlab GUIs.

Thanks for the addlistener tip! That always bugged me.

17 Jan 2014 Adam Filion

Cool tool, wish I had this back in grad school when I was working through Nonlinear Dynamics and Chaos by Strogatz. I have a few suggestions.

- Personally, I find it much easier to build and maintain apps in MATLAB as handle classes rather than through purely functional programming. You can find an article introducing the idea and why it should be used here:
http://www.mathworks.com/company/newsletters/articles/writing-apps-in-matlab.html

- Remove any menus or toolbar buttons you don’t want users playing with. There’s no reason to use things like the 3D rotate tool with this app. For example, you can remove all of them with:
menus = findall(gcf,'Type','uimenu');
delete(menus)
toolbar = findall(gcf,'Type','uitoolbar');
delete(toolbar)

- Try using addlistener to create continuous feedback when dragging sliders, something like the following has worked well for me.
myslider = uicontrol('Style', 'slider', 'Callback', @sliderCB);
addlistener(myslider,'ContinuousValueChange',@sliderCB);

- There's a small typo in two dimension example, missing a {

15 Mar 2013 Henry Harrison

I'm open for suggestions for useful features.

Updates
15 Mar 2013

Minor change in a user message.

15 Mar 2013

Added an acknowledgement I had left out.

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