# MATLAB assistance

#### THE_EGG

Hi all,

I'm having a problem with my MATLAB code I AM A NOOB TO PLEASE BE KIND D: (see below, I've pasted it). Now in the top code, this is my original one except I get no values for TTC (doesn't even appear in the workspace). So I did a bit of experimenting as I find trial and error usually sorts me out but I don't think it did this time. The bottom code is my experimental code, and I get the right number of values for TTC (1464x1) which is good as my excel file has 1464 values. Everything is fine but the TTC values I just can't get :/ If I could get some assistance that would be very much appreciated.

%assignment Problem 2

clc;
clear;
close;

%TTC means Time-To-Collision (s)
%Vf is the speed of the following vehicle (m/s)
%Vl is the speed of the leading vehicle (m/s)
%Ll is the length of the leading vehicle (m)

%b=a,1); %car
Vf=a,2); %Vf
Vl=a,3); %Vl
Ll=a,4); %Ll
t=a,5); %t
i=0;

d=(t.*Vf)-Ll; % see method for algebraic conversion from t=(d+Ll)/Vf

for i=1:length(d)
if (Vf-Vl)>0
TTC(i)=(d(i)./(Vf-Vl))
fprintf('TTC is equal to %f\n', TTC)
if TTC(i)<1
disp('The safety level is very dangerous')
elseif TTC(i)>1 && TTC(i)<4
disp('The safety level is dangerous')
elseif TTC(i)>4
disp('The safety level is safe')
end
if (TTC(i)<1)<0.03 && (TTC(i)>4)>0.8
else
disp('The road section is not safe')
end
elseif (Vf-Vl)<=0
%break
TTC(i)=inf;

end

end
fprintf('displaying TTC equals %f\n', TTC)

-------------------------------------

%assignment Problem 2

clc;
clear;
close;

%TTC means Time-To-Collision (s)
%Vf is the speed of the following vehicle (m/s)
%Vl is the speed of the leading vehicle (m/s)
%Ll is the length of the leading vehicle (m)

%b=a,1); %car
Vf=a,2); %Vf
Vl=a,3); %Vl
Ll=a,4); %Ll
t=a,5); %t
i=0;
TTC=0;

d=(t.*Vf)-Ll; % see method for algebraic conversion from t=(d+Ll)/Vf
TTC=(d./(Vf-Vl))

for i=1:length(d)
if (Vf-Vl)>0
TTC(i)=(d(i)./(Vf-Vl))
fprintf('TTC is equal to %f\n', TTC)
if TTC(i)<1
disp('The safety level is very dangerous')
elseif TTC(i)>1 && TTC(i)<4
disp('The safety level is dangerous')
elseif TTC(i)>4
disp('The safety level is safe')
end
if (TTC(i)<1)<0.03 && (TTC(i)>4)>0.8
else
disp('The road section is not safe')
end
elseif (Vf-Vl)<=0
%break
TTC(i)=inf;

end

end
fprintf('displaying TTC equals %f\n', TTC)

-----------------------------------------

Use code tags.

#### THE_EGG

Thanks hellrazor, it's ok though because I found my problem. I needed another if/else statement for the d value I obviously wasn't functioning too well at 11pm. :/