the value i am calling for from a matrix isnt changing although index is changing

so i am trying to call different values of T and p everytime I get one value of c that satisfies my requirements. As you can see although i,j changes to 1,4 here ( i tried debugging step by step to identify exactly why my conc matrix returns all the same values) the values of q and r dont change. i used q and r just as a reference to check whether my values of T and p were actually changing. So, how is it j=4 but when i call r=p(j) r returns 10 and not 40. I did the same code using for loop and i got my answers exactly but dont understand this. A clarification would be extremely helpful to remove my confusions regarding while loops.

[the cyclist]

Please post the code rather than an image of the code, so that we would not need to type it all in ourselves for testing.

[Dyuman Joshi]

Either copy and paste your code or attach the file using the paperclip button. Posting a picture of (half) your code is not helpful.

[Tanveer Islam]

clc

close

clear

f=@(T,C,p) (T/273.15)*(3.805*(C^2)+42.527*C+0.434)-p

df=@(t,c) (t/273.15)*(3.805*2*c+42.527)

a=3;

e=1;

conc=zeros(5,5);

T=[30,40,50,60,70];

p=[10,20,30,40,50];

for i=1:5

for j=1:5

while e>0.001

q=T(i);

r=p(j);

x=a-(f(T(i),a,p(j))/df(T(i),a));

e=abs(a-x);

a=x;

end

conc(i,j)=x;

continue

end

continue

end

conc

[Tanveer Islam]

Sorry I thought showing the workspace would be useful to pinpoint the problem I was facing

Answer 1

[Torsten]

You forgot to reset e to 1 after the while-loop.

[Tanveer Islam]

ive never been more disappointed in myself