How to plot the surface of multiple data sets ?

I have three different data sets each being constant in the z/l axis and want to plot the surface of them. I got the 3d plot working using plot3() :

All three lines have the same amount of data points so it should not be that hard to connect each point of each line with a straight line.

Here's the code for the figure:

figure(35);
set(gcf,'position',[x0,y0,width,height])

plot3(porous_upper(pathnumber_10,1).values(:,xc_x)*scale_x,porous_upper(pathnumber_10,1).values(:,xc_x+2)*scale_z,porous_upper(pathnumber_10,1).values(:,yc_x),"DisplayName","Porous Upper 1 p -10");
hold on;
plot3(porous_upper(pathnumber_10,2).values(:,xc_x)*scale_x,porous_upper(pathnumber_10,2).values(:,xc_x+2)*scale_z,porous_upper(pathnumber_10,2).values(:,yc_x),"DisplayName","Porous Upper 2 p -10");
hold on;
plot3(porous_upper(pathnumber_10,3).values(:,xc_x)*scale_x,porous_upper(pathnumber_10,3).values(:,xc_x+2)*scale_z,porous_upper(pathnumber_10,3).values(:,yc_x),"DisplayName","Porous Upper 3 p -10");

title(["Pressure p above porous layer";"Sidecoefficent Test -10"],'interpreter','latex',"FontSize",20)

set(gca, 'YDir','reverse')
xlabel('X/L', 'Interpreter','latex',"FontSize",16);
ylabel('Z/L', 'Interpreter','latex',"FontSize",20);
zlabel('$p$', 'Interpreter','latex',"FontSize",20);
legend("show","Location","Best","AutoUpdate", "off");

Answer 1

[Star Strider]

It would help to have the actual data.

N = 20;
X = (0:N-1);
Y = [1:3].'+zeros(size(X));
porous_upper = rand(20,3)+[0:2];

figure
plot3(X, Y(1,:), porous_upper(:,1))
hold on
plot3(X, Y(2,:), porous_upper(:,2))
plot3(X, Y(3,:), porous_upper(:,3))
hold off
grid on

figure
surf(porous_upper.')

Make appropriate changes to work with your data.

.

[Jean Volkmar]

Thank you for the answer, i attached the data. Coloumn 4 represents the z axis while column 7 the x axis and column 9 the y axis when using plot3(x,y,z).

porous_upper is a n x 3 struct where porous_upper(n,1) reffers to the data file if Porous_Upper_1 and so on. With only 3 data files n will be 1.

Edit:

As i understood your example uses the row and colomun numbers from porous_upper as x and y coordinate and the z coordinate is saves into the corresponding cell. However this wont work for me since my data points are not integers with a spacing of exactly 1 to each other.

[Star Strider]

My pleasure!

I am not certain what result you want.

One option (essentially my previous code with your data) —

T1 = readtable('https://www.mathworks.com/matlabcentral/answers/uploaded_files/717019/Porous_Upper_1.csv', 'VariableNamingRule','preserve');
T2 = readtable('https://www.mathworks.com/matlabcentral/answers/uploaded_files/717009/Porous_Upper_2.csv', 'VariableNamingRule','preserve');
T3 = readtable('https://www.mathworks.com/matlabcentral/answers/uploaded_files/717014/Porous_Upper_3.csv', 'VariableNamingRule','preserve');

% Q1 = [size(T1); size(T2); size(T3)]

Q1 = 3×2

1001 9 1001 9 1001 9

X = [T1{:,7}  T2{:,7}  T3{:,7}];
Y = [T1{:,9}  T2{:,9}  T3{:,9}];
Z = [T1{:,4}  T2{:,4}  T3{:,4}];

figure
hold on
for k = 1:size(Z,2)
    plot3(X(:,k), Y(:,k), Z(:,k))
end
hold off
grid on
view(150,30)
xlabel('X')
ylabel('Y')
zlabel('Z')
legend(compose('Upper Porous %d', 1:3), 'Location','bestoutside')

figure
meshc(X, Y, Z)
% surfc(X, Y, Z, 'EdgeColor','none')
grid on
view(150,30)
xlabel('X')
ylabel('Y')
zlabel('Z')

Make appropriate changes to get the result you want.

.

[Jean Volkmar]

Many thanks ! That:

X = [T1{:,7}  T2{:,7}  T3{:,7}];
Y = [T1{:,9}  T2{:,9}  T3{:,9}];
Z = [T1{:,4}  T2{:,4}  T3{:,4}

was the information i was missing. Is there also a way to control the mesh density, like here ?

[Star Strider]

My pleasure!

Reducing the mesh density requires reducing the plotted data, since the data define the surface. I am not certain what result you want. One option is to use surf (or surfc instead, my initial choice), and ‘turn off’ the edge lines:

T1 = readtable('https://www.mathworks.com/matlabcentral/answers/uploaded_files/717019/Porous_Upper_1.csv', 'VariableNamingRule','preserve');
T2 = readtable('https://www.mathworks.com/matlabcentral/answers/uploaded_files/717009/Porous_Upper_2.csv', 'VariableNamingRule','preserve');
T3 = readtable('https://www.mathworks.com/matlabcentral/answers/uploaded_files/717014/Porous_Upper_3.csv', 'VariableNamingRule','preserve');

% Q1 = [size(T1); size(T2); size(T3)]

X = [T1{:,7}  T2{:,7}  T3{:,7}];
Y = [T1{:,9}  T2{:,9}  T3{:,9}];
Z = [T1{:,4}  T2{:,4}  T3{:,4}];

figure
surfc(X, Y, Z, 'EdgeColor','none')
grid on
view(150,30)
xlabel('X')
ylabel('Y')
zlabel('Z')

or alternatively using the shading function:

figure
surfc(X, Y, Z)
grid on
view(150,30)
xlabel('X')
ylabel('Y')
zlabel('Z')
shading('interp')                                   % Added

Rotate it using the view function to the orientation you want.

.

[Jean Volkmar]

Alright thanks alot ! :)

[Star Strider]

As always, my pleasure!

.