MexJSBSim

A Matlab Mex-Function to use JSBSim from Matlab command line

The Matlab Mex-Function MexJSBSim is an attempt to establish a sort of standardized way of using a JSBSim::FGFDMExec object from Matlab command line.
Currently, this project is developed under the Windows platform (32 bits). Yet, the source code is platform-independent.
Every suggestion or criticism is welcomed.
Download the archive JSBSim_Matlab.zip

Compiling tips

On Windows platforms this Mex-Function can be compiled and debugged with Visual Studio 2008.
The file MexJSBSim.mexw32 is understood by the Matlab application as a command, just like an M-file.
To compile, just use the solution file MexJSBSim.sln, adjusting the include and lib directories as necessary.

For example:

if you use Matlab 2008b installed in C:\Program Files\MATLAB\R2008b, in the MexJSBSim project you need to set the dirs:
C:\Program Files\MATLAB\R2008b\extern\include and C:\Program Files\MATLAB\R2008b\extern\lib\win32\microsoft
to link the Matlab libs: libmx.lib libmex.lib libmat.lib.

The Mex-Function is also linked to the static library JSBSimLib.lib, which is made out of the latest JSBSim distribution (this project is also included in the solution).

Example of output of the command:

>>MexJSBSim('help')

function usage:
result = MexJSBSim( string_directive [, string, value] )

Examples:
    res = MexJSBSim('help');
       Prints this help text. returns 1 (always)

    res = MexJSBSim('open','c172r');
       returns 1 if success, 0 otherwise

    res = MexJSBSim('get','fcs/elevator-cmd-norm')
       returns the value of the property,
       or -9999 if property not found

    res = MexJSBSim('set','fcs/elevator-cmd-norm',-0.5)
       returns 1 if success, 0 otherwise

    res = MexJSBSim('set','elevator-cmd-norm',-0.5)
    res = MexJSBSim('set','u-fps',80.5)
       same as above, but it scans a set of predefined,
       and commonly used variable names:
            'u-fps', 'v-fps', 'w-fps'
            'p-rad_sec', 'q-rad_sec', 'r-rad_sec'
            'h-sl-ft'
            'long-gc-deg'
            'lat-gc-deg'
            'phi-rad', 'theta-rad', 'psi-rad'
            'elevator-cmd-norm'
            'aileron-cmd-norm'
            'rudder-cmd-norm'

    res = MexJSBSim('init',ic)
       initializes the JSBSim::FGFDMExec by means of the
       matlab structure ic.
       The structure ic must have the two fields: name and value.
       The Matlab user is forced to build such a structure first,
       then to pass it to the mex-file. Example:
       >> ic(1).name = 'u-fps'; ic(1).value = 80;
       >> ic(2).name = 'v-fps'; ic(2).value = 0;
       >> ic(3).name = 'w-fps'; ic(3).value = 0;
       >> ic(4).name = 'p-rad_sec'; ic(4).value = 0;
       >> MexJSBSim('init', ic);

    res = MexJSBSim('dot',ic)
       same as above.
       returns a res vector containing the following time rates.
       ___ body-axis velocity component rates
       res( 1) : u_dot (ft/s/s)
       res( 2) : v_dot (ft/s/s)
       res( 3) : w_dot (ft/s/s)
       ___ body-axis angular velocity component rates
       res( 4) : p_dot (rad/s/s)
       res( 5) : q_dot (rad/s/s)
       res( 6) : r_dot (rad/s/s)
       ___ orientation quaternion component rates
       res( 7) : q1_dot
       res( 8) : q2_dot
       res( 9) : q3_dot
       res(10) : q4_dot
       ___ ECEF position vector component rates
       res(11) : x_dot (ft/s)
       res(12) : y_dot (ft/s)
       res(13) : z_dot (ft/s)
       ___ Euler angle rates
       res(14) : phi_dot   (rad/s)
       res(15) : theta_dot (rad/s)
       res(16) : psi_dot   (rad/s)
       ___ Altitude rate
       res(17) : h_dot     (ft/s)
       ___ Aerodynamic angle rates
       res(18) : alpha_dot (rad/s)
       res(19) : beta_dot (rad/s)