How to plot a smooth curve with only a few points?

Hi,

I have 6 data points, it's very little, but it's all I have. How do I get a smooth plot from that? Like Excel has the option, by I want to use matlab.

time = PENO(:,1);

s24 = PENO(:,2);

sx24 = smooth(s24)

plot(time,sx24,'-o','Color',blue,'LineWidth',1.5,'MarkerSize',5,'MarkerFaceColor',blue);

This is what I get: The blue line is the original plot, without the smooth. And then I tried to smooth, which is the black line.

Answer 1

[Jan]

Either decide for a linear interpolation:

x = 1:6;
y = rand(1, 6);
plot(x, y, 'ko');
hold on

xx  = linspace(1, 6, 100);
yy1 = interp1(x, y, xx, 'cubic');
plot(xx, yy1, 'r-');

yy2 = interp1(x, y, xx, 'spline');
plot(xx, yy2, 'b-');

yy3 = interp1(x, y, xx, 'makima');
plot(xx, yy3, 'c-');

Or if you know the function of your data, fit a model to the measured values.

[Herline van der Spuy]

Brilliant! Thank Jan. I really appreciate this.