Slice command for terrain

Hi,

After dowloading topo data (.tif) from opentopography.org. I use "Imread". For plotting the data

A=imread('appRasterNEDAPIService1708354512850-756880040.tif');

surf(A):

It plots the 3D terrain data.

The size of the A is 194x424. It contains elevation data. I want to use slice command but in slice command there are x,y,z, and v.

After meshgrid the dimesion of the x becomes 3D and the same for y and z for 'slice' command. v is the function.

But as I stated my terrain data can not be converted for slice command. Is there anything that helps me?

Thank you

Answer 1

[Walter Roberson]

No. Your data cannot be sliced.

Perhaps you might want to contour() the data, and get back the contour matrix, and use something like https://www.mathworks.com/matlabcentral/fileexchange/38863-extract-contour-data-from-contour-matrix-c to extract data from the contour matrix.

[burak ergocmen]

Thank you for the answer. I can use the contour.

A=imread('appRasterNEDAPIService1708354512850-756880040.tif'); % the size of the A matrix 194x324

X=1:324;

Y=1:194;

contour(X,Y,A);

However, I try to slice (not with slice command) the terrain from a point where the aircraft flies at time t to a runway. So the aircraft has a x,y and h (altitude) and there is a runway which also has a x,y and h (height of the runway). I want to slice a 2D plane from an aircraft to the runway. The 3D becomes 2D. Finally, 2D map has only 1 and 0 for a presence of a terrain. Is there a way to resolve this?

Thank you

[Walter Roberson]

I wonder whether you should be using geotiffread or readgeoraster instead of imread()

For what you are doing, that sounds like improfile

[burak ergocmen]

Thank you again

'improfile' can be good start for me but I need 2D plane. With 'improfile', only the line is taken into account. I want to give more information for my problem:

A=imread('appRasterNEDAPIService1708354512850-756880040.tif');

X=1:324;
Y=1:194;
[X,Y]=meshgrid(X,Y);
surf(X,Y,A)
hold on
contour3(X,Y,A,"k",'ShowText','on')

x2=[50 200 200 50 50]; %for the plane
y2=[50 50 170 170 50];
z2=[4200 3800 3800 4200 4200];
plot3(x2,y2,z2);
hold on
fill3(x2,y2,z2,'r')
textscatter3(50,50,4200,"aircraft",'ColorData',[0.5 0.6 0.7]);
textscatter3(200, 170, 3800,"runway", 'ColorData',[0.5 0.6 0.7]);

I draw a 2D plane (red). The aircraft and the runway positions are given. I it possible to create a new map from the intersection of the red plane and the terrain?? Finally I try to create a 2D map. The terrain data in this map is given as for terrain =1 and freeterrain=0. It becomes A= [0 0 0 0 0 0 0 0 ......; 0 0 0 0 0 1 1 1 0 0 0...]]. Maybe it is like that:

Thank you,

[burak ergocmen]

I use this code to plot the intersection.

https://www.mathworks.com/matlabcentral/fileexchange/48613-surface-intersection?s_tid=srchtitle

I appreciate your suggestion. Thank you