Index in position 1 is invalid. Array indices must be positive integers or logical values.

I am getting the following error: Index in position 1 is invalid. Array indices must be positive integers or logical values.

Can anybody tell me how can I fix it?

The error in this line:

while m(xm,ym)==0

And my code is:

close all

clear all

clc

xm=-13; ym=-13; th=pi/2;

rr=1; %Robot radius

r=rr; %vector

u=Control();

n=4; %Number of sensors

dT=0.4;

x=-13; y=-13;

for t=1:size(u,1)

v=u(1,t);

if u(2,t)~=0

w=u(2,t);

else

w=100*eps; % 100*eps because eps alone is too small, so causes division by zero problem

end

subplot(1,2,1);

m=Map();

x=x-v/w*sin(th)+v/w*sin(th+w*dT);%state update

y=y+v/w*cos(th)-v/w*cos(th+w*dT);%state update

th=th+w*dT;%state update

for k=0:n-1

th=th+2*pi*k/n;

while m(xm,ym)==0 %if the location not occupied

xm=xm+r*cos(th); %corridnates(x,y) for the robot location

ym=ym+r*sin(th); %r is length(r)

r=rr+0.05;

if m(xm,ym)~=0 %if the location occupied

subplot(1,2,2);

mesh(xm,ym,m); view(0, 90); axis image; hold on;

plot(xm,ym,'b.');

end

end

end

end

[Sargondjani]

it would help a lot if you tell us in which line the error occurs. And just post the relevant part of your code. You can also add a "dbstop if error' so you can access all variables in memeory at the time the error occurs

[GHADAH AL-OBAIDI]

The error in this line:

while m(xm,ym)==0

[Paul Hoffrichter]

Duplicate questions (as of 2021-04-27):

https://www.mathworks.com/matlabcentral/answers/806792-index-in-position-1-is-invalid-array-indices-must-be-positive-integers-or-logical-values?s_tid=prof_contriblnk

https://www.mathworks.com/matlabcentral/answers/805766-index-in-position-1-is-invalid-array-indices-must-be-positive-integers-or-logical-values?s_tid=prof_contriblnk

https://www.mathworks.com/matlabcentral/answers/813670-create-100-random-particles-all-the-same-size-in-an-empty-plot-with-dimensions-x-axis-from-16-to?s_tid=srchtitle

https://www.mathworks.com/matlabcentral/answers/809330-index-in-position-1-exceeds-array-bounds-must-not-exceed-641-error-in-measurements-line-117?s_tid=prof_contriblnk

Answer 1

[Paul Hoffrichter]

Would be very useful if you are able to post a minimal program exhibiting the error that we could run. In the debugger, set the Run button to "Pause on Error". When the program breaks at the error, check that xm and ym are scalars, and check that they are both greater than 0.