How to plot 2 surfaces in a same chart?

I need to plot 2 surface in a same chart, but facing errors when plotting the first surface itself. So yet to try how to plot 2 surface in the same chart.

I am trying to plot a surface as below:

a=readtable(file.csv);

X=a(:,1);

Y=a(:,2);

Z=a(:,3);

surf(X,Y,Z)

I am facing the below errors:

Error using tabular/length (line 212)

Undefined function 'LENGTH' for input arguments of type 'table'. Use the HEIGHT,

WIDTH, or SIZE functions instead.

Error in surf (line 60)

hasParentArg = strncmpi(args{i}, 'parent', length(args{i}));

Error in Plot_forces (line 7)

surf(X,Y,Z)

Please guide me as I am new to matlab.

Answer 1

[Sulaymon Eshkabilov]

% To create a surface you need 2D data for Z
a=readtable(file.csv);
X=a(:,1); 
Y=a(:,2); 
[x, y] = meshgrid(X, Y);
Z = ....  % some f(x, y) math expression
% OR
z= meshgrid(Z);
surf(x,y,z)

[Manoj Krishnan Srinivasan]

Hello sir, I have a table of 1000 rows with X,Y,Z & X1,Y1,Z2 columns. Will I be able to create to create surface plot with the Z, Z1 data in my table?

[Sulaymon Eshkabilov]

Yes, you can by using meshgrid().

[Manoj Krishnan Srinivasan]

a = readtable('file.csv');

X = a(:,1);

Y = a(:,2);

Z = a(:,3);

[x,y] = meshgrid(X,Y);

Z = meshgrid(Z);

surf(x,y,z)

Still facing some error sir:

Error using meshgrid (line 59)

Subscripting into a table using one subscript (as in t(i)) or three or more

subscripts (as in t(i,j,k)) is not supported. Always specify a row subscript and a

variable subscript, as in t(rows,vars).

Error in Plot_forces (line 7)

[x,y] = meshgrid(X,Y);

[Sulaymon Eshkabilov]

Note that while importing your data from *.csv, your imported data will be in a table variable format and thus, you'd need to convert it into matrix format. Therefore, you should use the conversion first:

X =  table2array(a(:,1));
Y =  table2array(a(:,2));
Z =  table2array(a(:,3)); 
%%
[x,y] = meshgrid(X',Y');
z = meshgrid(Z');
surf(x,y,z)

One more thing,note that Z and z are not the same variable names.

In your case, it make more sense to plot your 3 data arrays using plot3(X, Y, Z)

Good luck.

[Manoj Krishnan Srinivasan]

It works now, thank you sir.