Plotting a graph through the points

Hello everyone,

I have collected this experimental data from the lab where x is time with 1 being 1 second 70 being 70 seconds and so on. I want the reading in y as points in which a curve can go through. Furthermore, I would like to insert this line into the same graph as my model. How do I do this? I have attached my code below for the plotting from the model.

x = [1 70 140 210 280 350 420 490 560 630 696]
y = [65.08  60.7 55.83 50.43 44.56 38.55  31.98 25.43 18.68 11.11 0]

figure (2)
plot(t(a),CAD(a),'Linewidth',2)
grid on
xlabel ('Time (s)')
ylabel ('\theta (\circ)')
title ('Contact Angle vs Evaporation Time')
legend('Theoretical','Experimental')

Thanks in advance for the help.

Answer 1

[dpb]

plot(x,y,'*-','LineWidth',2);
b1=polyfit(x,y,1);
y1=polyval(b1,[x(1),x(end)]);
hold on
plot([x(1),x(end)],y1,'r:');
b2=polyfit(x,y,2);
y2=polyval(b2,[x(1):x(end)]);
plot([x(1):x(end)],y2,'r-');

yields

The quadratic seems to do a very nice job -- of course, don't even try to use it to extrapolate more than a very, tiny, tiny, amount.

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Thank you. It worked

Answer 2

[Sudheer Bhimireddy]

You mean fitting a curve or polynomial function through the points?

Read: polyfit and you can modify the examples given there to your case.