Index exceeds the number of array elements (1) error on line 10

input('What parameter file do you want to use?'); % type parameters
P3(1:300) = P3d;
P3(301:500) = P3s;
for i = 1:N;
    P2(i) = (V2(i)-Vr)/C2;
    if P3(i)>P2(i); Q3(i) = (P3(i)-P2(i))/R2;
        else Q3 = 0;
    end
    Q1(i) = (P2(i)-P1)/R1;
    Q2(i) = Q1(i)-Q3(i);
    V2(i+1) = V2(i)+Q2(i)*dt;
end

[James Tursa]

Rachael, it is considered rude to delete your question once you have answers.

[Stephen23]

Original Question (in case it gets deleted again):

Index exceeds the number of array elements (1) error on line 10

input('What parameter file do you want to use?'); % type parameters
P3(1:300) = P3d;
P3(301:500) = P3s;
for i = 1:N;
    P2(i) = (V2(i)-Vr)/C2;
    if P3(i)>P2(i); Q3(i) = (P3(i)-P2(i))/R2;
        else Q3 = 0;
    end
    Q1(i) = (P2(i)-P1)/R1;
    Q2(i) = Q1(i)-Q3(i);
    V2(i+1) = V2(i)+Q2(i)*dt;
end

Answer 1

[Walter Roberson]

    if P3(i)>P2(i); Q3(i) = (P3(i)-P2(i))/R2;
        else Q3 = 0;
    end

The else of that overwrites all of Q3 with a scalar value. It would no longer have length greater than 1 for the Q3(i) reference further down.

[Rachael]

THANK YOU!