Can anyone please help me in plot of detaec' and taln. In this Iam getting error Error: Invalid expression. When calling a function or indexing a variable, use parentheses. Ot

clear all;

q=1.6e-19;

E0=8.85e-12;

Ealgan=10.31;

Ealn=10.78;

fib=(5.1*1.6e-19);

sigmaaln=3.38e17;

detaec=0.862;

talgan=23e-9;

p=(q^2/Ealgan*E0);

taln=0:0.1:2.5;

m=length(taln);

for i=1:m

detaec'(i)=[detaec+(p*sigmaaln*taln(i))];

end

plot(taln,detaec'(1,:),'b')

Answer 1

[Sam Chak]

Hi @Nudrat Sufiyan

From your parameters, ThisTerm returns a vector of very small values, because of your chosen value in p.

If the initial value is detaec(1) = 0.862, then the final value is also detaec(26) = 0.862.

q        = 1.6e-19;
E0       = 8.85e-12;
Ealgan   = 10.31;
sigmaaln = 3.38e17;
detaec   = 0.862;
p        = ((q^2)/Ealgan)*E0  % the same as q^2 / Ealgan * E0

p = 2.1975e-50

taln     = 0:0.1:2.5;
m        = length(taln)

m = 26

ThisTerm = p*sigmaaln*taln;
plot(taln, ThisTerm)

[Nudrat Sufiyan]

Thankyou very much sir, but this graph is not correct

[Sam Chak]

Hi @Nudrat Sufiyan

The graph was to show only this term: p*sigmaaln*taln, that the product values are too small () in this range 0 ≤ taln ≤ 2.5. If you can show the mathematical formula for detaec, perhaps we can work this out. Don't give up.

Answer 2

[Raghav]

Error: Invalid expression. When calling a function or indexing a variable, use parentheses.

You are using detaec' as a variable name, Special symbols anywhere in a variable name are syntactically invalid in Matlab. So the name detaec2 can be used.

After correctly renaming the variable you will be recieving a straight line in plot, because of value of detaec2 being equal to detaec(i.e. 0.862) as in the expression:

detaec2(i)=[detaec+(p*sigmaaln*taln(i))];

The value of p*sigmaaln*taln(i) will be almost equal to zero as p=2.1975e-50. So for all i, detaec2(i) will be 0.862.