MATLAB: What is the difference between these commands

3d plotsplotting

can anyone tell me the difference between plot3 and meshgrid and surf ?

plot3() plots some markers at the specified points. It does not make a solid surface between the markers.

surf() will create a solid surface between the points.

meshgrid() gives every possible combination of every x and every y. It is not a plotting function.

If I remember correctly, diff works across the first non-singleton dimension. So diff(A) works across columns and diff(A(1, :)) works across rows.

x = [1,2,3; 4,5,6];
diff(x, [], 1)
ans =
   3     3     3
diff(x, [], 2)
ans =
   1     1
   1     1

This code might do what you are looking for

ix = sscanf( T(:,end), '%1d' );
Y  = cat( 1, Y, rand );     % add one element to get 10
R  = Y(ix+1);

inspect the result

>> R(1:6)'
ans =
   11.1665   11.1665   11.1665   11.5740   11.5740   11.5740

where

T=['cluster2'
'cluster2'
'cluster2'
'cluster7'
'cluster7'
'etc ....'];