How to smooth contour lines for the given set of data

HI

I am trying to smooth the curve lines

for the given set of data

a=[0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4];

b=[0 0 0 0 0 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 4 4 4 4 4];

c=[0 0 0 0 0 0 0.689376362 1.378752724 2.068129087 2.757505449 0 1.02920355 2.0584071 3.087610649 4.116814199 0 1.216469264 2.432938529 3.649407793 4.865877057 0 1.325720912 2.651441823 3.977162735 5.302883646];

Anyone can help me to smooth the lines.

Answer 1

[Star Strider]

Increase the resolution of the vectors (and resulting matrices), and optionally define the 'method' as something other than 'linear'.

Example —

a=[0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4];
b=[0 0 0 0 0 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 4 4 4 4 4];
c=[0 0 0 0 0 0 0.689376362 1.378752724 2.068129087 2.757505449 0 1.02920355 2.0584071 3.087610649 4.116814199 0 1.216469264 2.432938529 3.649407793 4.865877057 0 1.325720912 2.651441823 3.977162735 5.302883646];

av = linspace(min(a), max(a), 150);
bv = linspace(min(b), max(b), 150);
[A,B] = ndgrid(av,bv);

C = griddata(a(:), b(:), c(:), A, B, 'natural');

figure
contourf(A,B,C)

Experiment to get the desired result.

.