1D Spline from 2D Skalar Field

Hello community,

I have a problem.

I have a 2D skalar-field and need support points to describe the red curve.

The red curve is any curve that projects a straight line onto the z=0 plane.

Below you can see a Plot of the 2D skalar-Flied, which I have as a matrix.

In addition, I have the mathematical description of the dark red line.

What are the z values of the light red line? (which I have inserted with Paint)

Thankyou for your Help.

Greetings, Florian

Answer 1

[Florian Flaig]

copy of marc li:

OK, if your surface data are X, Y and Z and your dark red line data are x and y, you can get data of the red line about z axis:

z = interp2(X,Y,Z,x,y);

and plot the red line:

hold on;
plot3(x,y,z)

Answer 2

[mark li]

You may get information of the curve by handles.

Firstly, you get the handle of the figure by gcf, the figure have three children which are a surface and two lines. The code is shown as

Child = get(gcf, 'Children');

The Child may be 3x1 handles, and you can :

get(child(1)), get(child(2)), get(child(3))

According to result, you select proper index.

[Florian Flaig]

Ah ok, thank you very much.

If I understand correctly, this is how I get information about the plot.

I have the matrix for the plot. And the description of the dark red line too. I now need the grid points (z coordinates) to plot the light red line.

[mark li]

OK, if your surface data are X, Y and Z and your dark red line data are x and y, you can get data of the red line about z axis:

z = interp2(X,Y,Z,x,y);

and plot the red line:

hold on;
plot3(x,y,z)

[Florian Flaig]

Thank you very mouch marc. Now it works. :-)