how to plot a matrix on a 3D graph

Hi,

I have a 6x6 matrix that I need to plot on an 3D graph. The elements 1-2-3-4-5 of the first column should be on the x axis, the elements 1-2-3-4-5 of the first row should be on the y axis, element 0,0 is NaN.

The remaining 5x5 array contains the values for the z axis.

Can somebody please help me how to plot it.

Thanks.

Answer 1

[Sean de Wolski]

[xx yy] = meshgrid(M(1,2:end),M(2:end,1));
plot3(xx(:),yy(:),reshape(M(2:end,2:end),[],1));

or surf or mesh whatever type of plot you want.

Addendum The best way to learn is to do it yourself and break down every line to see what's happening.

%Sample script to identify every op.
M = magic(6)
[xx yy] = meshgrid(M(1,2:end),M(2:end,1))
disp('M(2:end,2:end) = ');
M(2:end,2:end)
disp('M reshaped to column vector: ')
reshape(M(2:end,2:end),[],1)

M =

    35     1     6    26    19    24
     3    32     7    21    23    25
    31     9     2    22    27    20
     8    28    33    17    10    15
    30     5    34    12    14    16
     4    36    29    13    18    11

xx =

     1     6    26    19    24
     1     6    26    19    24
     1     6    26    19    24
     1     6    26    19    24
     1     6    26    19    24

yy =

     3     3     3     3     3
    31    31    31    31    31
     8     8     8     8     8
    30    30    30    30    30
     4     4     4     4     4

M(2:end,2:end) =

ans =

    32     7    21    23    25
     9     2    22    27    20
    28    33    17    10    15
     5    34    12    14    16
    36    29    13    18    11

M reshaped to column vector:

ans =

    32
     9
    28
     5
    36
     7
     2
    33
    34
    29
    21
    22
    17
    12
    13
    23
    27
    10
    14
    18
    25
    20
    15
    16
    11

The xx(:) operation does the same thing as reshape in this use of reshape.

[VELMURUGAN K]

Hi,

I have a 15x15 matrix that I need to plot on an 3D grid or surface graph. The elements 1-15 of the first column should be on the x axis, the elements 1-15 of the first row should be on the y axis, element 0,0 is NaN.

The remaining 14x14 array contains the values for the z axis.

Can somebody please help me how to plot it.

give the exmaple plot also

Thanks.

Answer 2

[krivan]

Can you please clarify which is doing what especially in the argument of the reshape and what exactly xx(:) does for example. I am just new to Matlab and couldn't find it in the manual.

Thanks.

Answer 3

[krivan]

Brilliant! Thanks for your help!