MATLAB: 4th degree question ploting

4th degreeMATLAB

Ctg =[0.322;0.122;0.084;0.053;0.031;0.01];

t =[0 20 40 60 80 100];

% 4th degree Equation

R = 1.914e-08*t4 -4.753e-06*t3 + 0.0004167*t2 – 0.01639*t+ 0.3213

How can I plot it to be like the attached image? please anyony

Best Answer

Try this:

Ctg =[0.322; 0.122; 0.084; 0.053; 0.031; 0.01];
t =[0; 20; 40; 60; 80; 100];
plot(t, Ctg, 'ko', 'LineWidth', 2, 'MarkerSize', 15);
hold on;
% Estimate the coefficients for a 4th order polynomial.
coefficients = polyfit(t, Ctg, 4)
% Make a new x
t = linspace(min(t), max(t), 1000);
% 4th degree Equation
R = coefficients(1)*t.^4 + coefficients(2)*t.^3 + coefficients(3)*t.^2 + coefficients(4)*t+ coefficients(5);
plot(t, R, 'b-', 'LineWidth', 2);
grid on;