How can fix index exceeds matrix error

mn=input('Modül Giriniz:');
T=input('Teeth Numbers :');
at=input('Transverse pressure angle: ');
ad=input('Addendum Coef: ');
de=input('Deddendum Coef :');
Hobtip=input('Hob Tip Radius coef: ');

rg=mn*T/2;
rr=rg-(de*mn);
br=rg*cosd(at);
tr=rg+(ad*mn);
b=(tr-br)/180;
r=br;
a=1;
r2=num2cell(br:b:tr);

inva=tand(at)-(at*pi/180);
ctt1=pi*mn/2;

%                                     Involute Curves
while r<=tr
    r=r+b;
    a=a+1;
end

for i=1:1:a
    
    teta{i}=acosd(br/r2{i});
    invteta{i}=tand(teta{i})-(teta{i}*pi/180);
    ctt2{i}=2*r2{i}*((0.5*ctt1/rg)+inva-invteta{i});
    B{i}=0.5*ctt2{i}/r2{i};
    x{i}=r2{i}*sin( B{i});
    y{i}=r2{i}*cos(B{i});
    leftx{i}=-1*r2{i}*sin(B{i});
end



%                         Trochoid Curves


B_tr=(de*mn)-(Hobtip*mn);
L=(pi*mn/4.0)-(B_tr*tand(at))-(Hobtip*mn/(cosd(at)));
W=((((pi*mn)/2.0)-L)/rg);
E=0;
e=E;
Emax=50*pi/180;
tro=Emax/179;
o=1;
E2=num2cell(0:tro:Emax);
while (e<=Emax)
    e=e+tro;
    o=o+1;
end
for q=1:o
    Yz{q}=((rg-B_tr)*cos(E2{q}))+((rg*E2{q}*sin(E2{q})));
    
    Xz{q}=(rg*E2{q}*cos(E2{q}))-((rg-B_tr)*sin(E2{q}));
    
    DXZ{q}=(-(rg*E2{q}).*sin(E2{q}))+((B_tr*cos(E2{q})));
    
    DYZ{q}=(B_tr*sin(E2{q}))+((rg*E2{q})*cos(E2{q}));
    
    if(E==0)
        A{q}=90*pi/180.;
    end
    A{q}=atan(DXZ{q}./DYZ{q});
    
    Xt{q}=Xz{q}+((Hobtip*mn).*cos(A{q}));
    
    Yt{q}=Yz{q}-(Hobtip*mn.*sin(A{q}));
    
    Xtr{q}=Yt{q}.*sin(W)-Xt{q}.*cos(W);
    
    Ytr{q}=Yt{q}.*cos(W)+Xt{q}.*sin(W);
    leftXtr{q}=-1.*(Yt{q}.*sin(W)-Xt{q}.*cos(W));
end
%      Tooth Curves
% Involute ones
plot(cell2mat(x),cell2mat(y));
hold on
plot(cell2mat(leftx),cell2mat(y));
hold on
% Trochoid Ones
plot(cell2mat(Xtr),cell2mat(Ytr));
hold on
plot(cell2mat(leftXtr),cell2mat(Ytr));

[BAHADIR Karba]

index exceeds matrix dimensions "teta{i}=acosd(br/r2{i}) 
"yz{q}=((rg-b_tr)*cos(e2{q}))+((rg*e2{q}*sin(e2{q})))" 
"xz{q}=(rg*e2{q}*cos(e2{q}))-((rg-b_tr)*sin(e2{q})) "

[Rik]

Have a read here (or here for more general advice). It will greatly improve your chances of getting an answer.

What have you tried to solve this problem yourself? Have you checked the dimensions of the arrays you're indexing when the error occurs?

[Luna]

Could you please define your inputs? So we can run your code?

mn=input('Modül Giriniz:');
T=input('Teeth Numbers :');
at=input('Transverse pressure angle: ');
ad=input('Addendum Coef: ');
de=input('Deddendum Coef :');
Hobtip=input('Hob Tip Radius coef: ');

[BAHADIR Karba]

case 1 :

mn=3

T=20

at=20

ad=1.0

de=1.25

Hobtip=0.38

whenever i used any pertinent inputs programs give errors especially like that

indexing exceed,actually main problem due to double / cells

"teta{i}=acosd(br/r2{i})

"yz{q}=((rg-b_tr)*cos(e2{q}))+((rg*e2{q}*sin(e2{q})))"

"xz{q}=(rg*e2{q}*cos(e2{q}))-((rg-b_tr)*sin(e2{q})) "

Even i take an error like that sometimes,if ı rewrite plots on the command section can show plots correctly,But most of trying give errors and program stopped due to errors

Answer 1

[Bob Thompson]

Your first error occurs with teta{i} = acosd(br/r2{i}); because r2 has one less element than the max values of i. I would suggest initializing a as 0 instead of 1.

I did not encounter the other errors.

[BAHADIR Karba]

Yes,I forgot this a and o values must be started from 0;and also solved.

Many thanks ,

Best regards