4d smooth plot with slices

Hello I have a txt file (I have attached it as "Data.txt") with 4 columns, each representing a variable x,y,z,v. I plot this in the following manner:

load("Data.txt")
x = Data(:,1);
y = Data(:,2);
z = Data(:,3);
v = Data(:,4);

scatter3(x,y,z,40,v,'filled')
colorbar

However I would like it to be a smooth object on which I can also take vertical, horizontal or whatever slices.

[Adam Danz]

surf(__) ?

[tandemuse]

surf doesn't accept 4 variables

[Adam Danz]

surf(X,Y,Z,C)

[tandemuse]

load ("Data.txt")
x = Data(:,1);
y = Data(:,2);
z = Data(:,3);
v = Data(:,4);

surf(x,y,z,v)

Error using surf (line 71)
Z must be a matrix, not a scalar or vector.

Or:

load ("Data.txt")
x = Data(1:10:end,1);
y = Data(1:10:end,2);
z = Data(1:10:end,3);
v = Data(:,4);

[x,y,z] = meshgrid(x,y,z);

surf(x,y,z,v)

Error using matlab.graphics.chart.primitive.Surface

Value must be a vector or 2D array of numeric type.

Error in surf (line 145)

hh = matlab.graphics.chart.primitive.Surface(allargs{:});

[Adam Danz]

Z must be a matrix. X and Y can be matricies the same size as Z or vectors that define the rows and columns of Z. V has several options but the easiest is probably a matrix the same size as Z.

Anyway, the slice function Bjorn mentioned may be better to accomplish you goal of taking slices of the object.

Answer 1

[tandemuse]

Solved it using the answer from:

https://www.mathworks.com/matlabcentral/answers/500825-how-to-obtain-volume-data-from-x-y-z-c-data-to-use-slice-function?s_tid=answers_rc1-1_p1_MLT

Answer 2

[Bjorn Gustavsson]

I suggest you use the slice function for that, this type of plots is what that function was designed for.

If your Data are not on a regular grid you will have to re-interpolate it to a regular x-y-z grid. You can do that using scatteredInterpolant, see the help and documentation for how to use that.

If your data is on a regular plaid grid you simply have to reshape the data into 3-D arrays. After that is done you can slice to your hearts desires:

slice(x3d,y3d,z3d,V,[1,2,exp(1),3,pi],[0,log(2),2^.5],1+sqrt(5)/2),shading flat

HTH

[tandemuse]

I take every 10th sample because otherwise meshgrid doesn't work:

load ("Data.txt")
x = Data(1:10:end,1);
y = Data(1:10:end,2);
z = Data(1:10:end,3);
v = Data(1:10:end,4);

The following produces an error:

F = scatteredInterpolant(x,y,z,v);
[xq,yq,zq] = meshgrid(x,y,z);
vq = F(xq,yq,zq);

slice(xq,yq,zq,vq,[],[],0)

Error using griddedInterpolant

Sample points must be unique and sorted in ascending order.

Error in interp3 (line 144)

F = griddedInterpolant(X, Y, Z, V, method,extrap);

Error in slice (line 103)

vi = interp3(x,y,z,v,xi,yi,zi,method);