Array indices must be positive integers or logical values.

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I keep getting the error "Array indices must be positive integers or logical values" on every equation within the for loop and I'm not sure what I'm doing wrong. I've looked through other posts with this error and I can't seem to find my error
clear
clc
% Set known variables
rho = 800; % kg/m^3
mu = 0.00035; % N*s/m^2
Q = 2; % m^3/s
n = 25; % unitless
g = 9.81; % m/s^2
L = 160934; % m
m_dot = rho*Q;
H = L/(m_dot*g);
D = 1:0.1:10;
for n = 1:length(D)
P(D) = (128*mu*(Q^2)*L)./(pi*(D.^4));
CQ(D) = (P)./(rho*(n^3)*(D.^5));
CH(D) = (g*H)./((n^2)*(D.^2));
CQ(D) = Q./(n*(D.^3));
end

Answers (1)

madhan ravi
madhan ravi on 2 Jun 2020
Left hand side of the equation (n) and in right hand side D(n).
And Ofcourse you don’t need a loop here ;)
  2 Comments
madhan ravi
madhan ravi on 2 Jun 2020
% Set known variables
rho = 800; % kg/m^3
mu = 0.00035; % N*s/m^2
Q = 2; % m^3/s
n = 25; % unitless
g = 9.81; % m/s^2
L = 160934; % m
m_dot = rho*Q;
H = L/(m_dot*g);
D = 1:0.1:10;
n = 1:numel(D);
P = (128*mu*(Q^2)*L)./(pi*(D.^4));
CQ = P ./(rho*(n.^3).*(D.^5));
CH = (g*H)./((n.^2).*(D.^2));
CQ = Q./(n.*(D.^3));

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