Plotting 3D points from numerous arrays

Hello all,

I have 210 arrays each one representing the x,y,z coordinates of a point (70 points). My arrays are named Point_1_x, Point_1_y, Point_1_z, etc.

I want to plot a 3D plot of the 70 points at a specific time (assume 20,1 cell in all arrays.

Is there a way to write a loop for the whole procedure with i ranging from 1 to 70 to create this plot as automatically as possible?

Thank you in advance.

[Dimitrios]

Make it more clear Kwstas! :D

Answer 1

[Konstantinos Belivanis]

Well actually, you appented all the points. What I would like is to show all the points (70 points in one plot) at the same time (t=20) in one plot.

[Orion]

In the first part, I concatenate all the points to have just 3 arrays to manipulate.

and at the end,

plot3(XatTime,YatTime,ZatTime);

should just be replace by :

plot3(XatTime,YatTime,ZatTime,'+'); % to show the 70 points instead of drawing a line.

And then again, I don't know your data. you said at the same time (t=20). where is your time vector ? what index corresponds in the array Point_1_x/y/z ?

[Konstantinos Belivanis]

So imagine 210 column arrays with titles Point_1x, etc... and each row represent the specific coordinate at a specific time step. So I would like a loop like this one to create a set of X Y Z coords like that

t=20;

for i=1:70

X_Coords=Point_i_x(t,1);

Y_Coords=Point_i_y(t,1);

Z_Coords=Point_i_z(t,1);

end

and then plot each vector of components?

the problem is that the i in the title of the array should not be written like this.

Any idea?

[Orion]

this should work

t=20;
% init
X_Coords = zeros(70,1);
Y_Coords = zeros(70,1);
Z_Coords = zeros(70,1);
% loop on 70 files for the time t
for i=1:70    
    X_Coords(i) = eval(sprintf('Point_%d_x(t,1)',i));    
    Y_Coords(i) = eval(sprintf('Point_%d_y(t,1)',i));    
    Z_Coords(i) = eval(sprintf('Point_%d_z(t,1)',i));    
end

% draw
plot3(X_Coords,Y_Coords,Z_Coords,'+');

[Konstantinos Belivanis]

Thanks a lot!!! The eval(sprintf('Point_%d_x(t,1)',i)) was what I was looking for :)

Solved!

Answer 2

[Orion]

I don't have data to work with and see the validity of the result, but I guess you need something like

% create array by concatenating the vectors for each directions.
% assuming all Point_1_x, Point_1_y, Point_1_z, etc. are columns vectors.
AllXdat = [];
AllYdat = [];
AllZdat = [];
for i = 1:70
    AllXdat = [AllXdat eval(sprintf('Point_%d_x',i))];
    AllYdat = [AllYdat eval(sprintf('Point_%d_y',i))];
    AllZdat = [AllZdat eval(sprintf('Point_%d_z',i))]; 
end

% define the time you want to plot, and get the corresponding spatial values, 
% assuming the value fot t = 20 is at the 20th position in the vectors : Point_1_x(20),...
mytime  = 20;
XatTime = AllXdat(mytime,:);
YatTime = AllYdat(mytime,:);
ZatTime = AllZdat(mytime,:);

% plot at the desired time
plot3(XatTime,YatTime,ZatTime);

[Konstantinos Belivanis]

Could I add the name of each point next to each point? (to be able to identify them on the graph)?

Answer 3

[Daniel Iyinomen]

How can I use Surf to plot 3D graph from a text file. The text is attached and the auto-generated surface is also attached. My problem is drawing the attached auto-generated plot in MATLAB using the attached text file. Please, any help?