Graphing a variable function with boundaries problem

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i am trying to plot the function that is shown in the picture. Matlab keep giving me the error "Error: File: Q4.m Line: 11 Column: 64
Invalid expression. When calling a function or indexing a variable, use parentheses. Otherwise, check for
mismatched delimiters."
Refers to P_0_1 in the loop Screen Shot 2019-09-24 at 12.52.30 PM.png
%Part a)
R=287; % Specific gas constant in J/kg.k
M=[2:0.1:6];
gamma=1.4;
P_0_1=101325; % Pressure at sea level in Pa unit
for n=1:length(M);
P_0(n,1)=((1+((gamma-1))/2).*M(n).^2).^(gamma/(gamma-1)).*P_0_1);
end
P_0_ratio=P_0./P_0_1;
figure (1)
plot (M, P_0_ratio)
xlabel('Moch Number')
ylabel('Total stagnation pressure ratio P_0/P_0_1')
title('Total stagnation pressure ratio P_0/P_0_1 vs. Moch Number')
%Part b)
for n=1:length(M);
delta_s_r(n,1)=-log(P_0_ratio(n));
end
figure(2)
plot (M,delta_s_r)
xlabel('Moch Number')
ylabel('Dimensionless entropy change \delta s')
title('Dimensionless entropy change \delta s vs. Moch Number')

Accepted Answer

Ruger28
Ruger28 on 24 Sep 2019
Edited: Ruger28 on 24 Sep 2019
Removing the extra " ) " at the end of that line, yields plots and no errors.
%Part a)
R=287; % Specific gas constant in J/kg.k
M=[2:0.1:6];
gamma=1.4;
P_0_1=101325; % Pressure at sea level in Pa unit
for n=1:length(M);
P_0(n,1)=((1+((gamma-1))/2).*M(n).^2).^(gamma/(gamma-1)).*P_0_1;
end
P_0_ratio=P_0./P_0_1;
figure (1)
plot (M, P_0_ratio)
xlabel('Moch Number')
ylabel('Total stagnation pressure ratio P_0/P_0_1')
title('Total stagnation pressure ratio P_0/P_0_1 vs. Moch Number')
%Part b)
for n=1:length(M);
delta_s_r(n,1)=-log(P_0_ratio(n));
end
figure(2)
plot (M,delta_s_r)
xlabel('Moch Number')
ylabel('Dimensionless entropy change \delta s')
title('Dimensionless entropy change \delta s vs. Moch Number')
  1 Comment
Mohsen Nashel
Mohsen Nashel on 24 Sep 2019
Thank you! Rushing to finish homework can't figure out anything! You are a scholar!!

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