Interpolate data to present with limited size of data

Suppose I only have 35 data points, it is very expensive to run.

x=rand(5,7)
figure
imagesc(x)

axisx=[11 12 13 14 15 16 17]
axisy=[10 20 30 40 50]

Is there any way to present them smoother, using imagesc gives too pixel. Is there any interpolation?

and display the axis with my axisx and axisy

[William Rose]

@Davide Masiello, nice!

Answer 1

[Davide Masiello]

x=rand(5,7)

x = 5×7

0.2207 0.4751 0.9818 0.6898 0.8489 0.7640 0.3894 0.1370 0.3264 0.7110 0.4195 0.6313 0.4999 0.0168 0.9267 0.9988 0.6922 0.3023 0.1398 0.5576 0.8856 0.2924 0.5511 0.0081 0.9578 0.6766 0.4339 0.1714 0.5717 0.5432 0.3209 0.2490 0.3414 0.1640 0.6649

figure
contourf(x,'LineColor','none')
shading interp
axis equal off

[Miraboreasu]

Is there a way to eliminate the lines? and sorry I add about the axis displacement

[William Rose]

@Miraboreasu,

Z=2*rand(5,7);
[X,Y]=meshgrid(0:6,0:4);            %locations of the known values
surf(X,Y,Z,'EdgeColor','None');
axis equal

Now compute interpolated values and plot the interpolated values:

[Xi,Yi]=meshgrid(0:.2:6,0:.2:4);  %locations for interpolation
Zi=interp2(X,Y,Z,Xi,Yi);
surf(Xi,Yi,Zi,'EdgeColor','None');
axis equal

This surface is more filled in and as a result the coloring looks better. In the example above, the inteprolaiton was linear, by default. You can use smoother interpolaiton to get an even smoother plot. See below:

Zi2=interp2(X,Y,Z,Xi,Yi,'makima');
surf(Xi,Yi,Zi2,'EdgeColor','None');
axis equal

Looks smooth. YOu can also plot this as floows:

figure
contourf(Zi2,'LineColor','none')
shading interp
axis equal off

Not bad.

[Miraboreasu]

@William Rose

Thank you, I think I need to rephase my quesiton, but I don't if I need to post a new thread, I will ask here first.

So for this matrix,

x=rand(5,7)

each row is one variable changing

axisx=[11 12 13 14 15 16 17]

each column is another variable changing

axisy=[10 20 30 40 50]

the value of the matrix like x(1,2) is what I want to show in colorbar

What is the best way to present them? with axis

[Davide Masiello]

axisx = [11 12 13 14 15 16 17];
axisy = [10 20 30 40 50];
[x,y] = meshgrid(axisx,axisy);
z     = rand(5,7);

[x_new,y_new] = meshgrid(linspace(axisx(1),axisx(end),100),linspace(axisy(1),axisy(end),100));
z_new         = interp2(x,y,z,x_new,y_new);

contourf(x_new,y_new,z_new,linspace(min(z(:)),max(z(:)),100),'LineColor','none')
shading interp
colorbar
xlabel('x axis')
ylabel('y axis')