ERROR: Array indices must be positive integers or logical values

An error occurred while running the simulation and the simulation was terminated

Caused by:

• Error due to multiple causes.
• Array indices must be positive integers or logical values.
• Error in airshipsystemsimulation/Interpreted MATLAB Function5 while evaluating expression

%MATLAB FUNCTION CODE (USED WITHIN INTERPRETED MATLAB FUNCTION BLOCK WITH 9 INPUTS):
function op=airshipsyspgmoutqdot(u)
%inputs
ue=u(1);ve=u(2);we=u(3);
pe=u(4);qe=u(5);re=u(6);
phie=u(7);thetae=u(8);psie=u(9);

%%
%parameters
m=9.07;
B=72.2;
W=89;V=7.6;L=6;D=1.4;
a_z=-0.041;
Xx=1.12; Yy=7.25; Zz=7.25;
Kpdot=0;Mqdot=8.87;Nrdot=8.87;
Ix=2.19;Iy=18.85;Iz=18.76;
Ixz=0;
Xu=-10;Yv=-10;Zw=-10;Lp=-10;Mq=-10;Nr=-10;
Jx=Ix-Kpdot;Jy=Iy-Mqdot;Jz=Iz-Nrdot;Jxz=0;
mx=m-Xx;my=m-Yy;mz=m-Zz;
Tr=0.1;Tl=0.1;
%%
c1=cos(phie);c2=cos(thetae);c3=cos(psie);
s1=sin(phie);s2=sin(thetae);s3=sin(psie);
t2=tan(thetae);
qdot=0.0047*(-mz*we*qe+my*we*ve-m*a_z*pe*re-(W-B)*s2)+...
    0.1004*((Jx-Jz)*pe*re+Jxz*((re).^2-(pe).^2)+m*a_z*(qe*we-re*ve)-W*a_z*s2-10+(Tr+Tl)*a_z);
op=qdot;
end

Answer 1

[Walter Roberson]

That code looks okay, other than not being documented.

However, it does not have 9 inputs, and this structure would normally be called a MATLAB Function Block but not an Interpreted MATLAB Function block: the Interpreted MATLAB Function blocks referred to a block that can only accept a single expression (that could call functions.)

So potentially the fault is not this routine, but another block calling this routine.

[Drishya Dinesh]

Thank-you sir, that worked.