How to create a 3D plot and split the values inside?

Let´s say I have 3 coordinates, x,y and z

x goes from 0 to 120 with a step of one

y goes from 0 to 200 with a step of one

z goes from -25 to 25

The values inside vary, for example:

vector = ( x, y , z)

2.5 = ( 10, 22, -5 )

How can I later make divisions on this data based on the value of the vector or values inside the entire matrix.

Something like the image above.

Answer 1

[darova]

Use logical operations

id = vector > 2.5;
plot3(x(ix),y(ix),z(ix),'.r')           % plot only points where vector > 2.5

[Mariana]

The problem is that the coordinate is not the one that defines te division of colors. The stored value inside the coordinate is the one that defines it.

[darova]

Can you show your data? Formulas?

[Mariana]

Sure.

data/data1/data2/data3/data4/data5 are my 2D tables

x goes from 0 to 120 with a step of one

y goes from 0 to 200 with a step of one

z is the third coordinate.

I will first read the value of z if it is between 0 and -5. Then I will use data1 instead of data.

%Input
y= 100;
x= 80;
z= -4;

%Conditions
if z >= 0
    val = timegap(y,x,1);
    disp(val);
    if val > 2
       disp('Save zone') 
    else
       disp('Danger zone')
     end
elseif (0>z) && (z>-5) 
    val = timegap(y,x,2);
    disp(val);
     if val > 2
       disp('Save zone') 
     else
       disp('Danger zone')
     end
    end

The value of z defines which 2d table I will use. I want to make a 3d plot so that I can show to people that the more negative my z value the values inside my 2D decrease.

Please let me know if I had explained myself

[darova]

What about slice?

opengl software

load data_val.mat
[m,n,k] = size(timegap);
ii = 1:10:m;
jj = 1:10:n;
z = -4:1:10;
kk = (z>=0) + 2*((-5<z)&(z<0));     % 1 if z>=0, 2 if -5<z<0
val = timegap(ii,jj,kk);            % choose values
% zone = val > 2;
[Y,X,Z] = ndgrid(ii,jj,z);

cla
xslice = [25 80];
yslice = [20 180];
zslice = [-2 8];
h = slice(X,Y,Z,val,xslice,yslice,zslice);  % create volume slices
set(h,'edgecolor','none')
alpha(0.3)                                  % make slice transparent
for zone = [0.1 2 15]
    isosurface(X,Y,Z,val,zone);             % create zones
end

colorbar
axis vis3d
xlabel('X')
ylabel('Z')
zlabel('Z')

Result

[Mariana]

I need to plot all the values inside the 6 2D tables and then split into two sections. When the value inside that coordinate is higher than 2 is green if it is less than 2 then it should be red.

[darova]

Change these lines

kk = 1:6;
val = timegap(ii,jj,kk);            % choose values
[Y,X,Z] = ndgrid(ii,jj,kk);

And add these

ival = val > 2;
hold on
plot3(X(ival),Y(ival),Z(ival),'.g','markersize',15)
plot3(X(~ival),Y(~ival),Z(~ival),'.r','markersize',15)
hold off

result

[Mariana]

opengl software

load data_val.mat
[m,n,k] = size(timegap);
ii = 1:10:m;
jj = 1:10:n;
z = -4:1:10;
kk = 1:6;
val = timegap(ii,jj,kk);            % choose values
[Y,X,Z] = ndgrid(ii,jj,kk);
cla
xslice = [25 80];
yslice = [20 180];
zslice = [-2 8];
h = slice(X,Y,Z,val,xslice,yslice,zslice);  % create volume slices
set(h,'edgecolor','none')
alpha(0.3)                                  % make slice transparent
for zone = [0.1 2 15]
    isosurface(X,Y,Z,val,zone);             % create zones
end

colorbar
axis vis3d
xlabel('X')
ylabel('Y')
zlabel('Z')

ival = val > 2;
hold on
plot3(X(ival),Y(ival),Z(ival),'.g','markersize',15)
plot3(X(~ival),Y(~ival),Z(~ival),'.r','markersize',15)
hold off

I am not getting the same result as you did. Where is my mistake?

[darova]

[Mariana]

Is it possible to get rid of the slides?

[darova]

Of course. Get rid of them

[Mariana]

How can I create a function based on the created plane?

[darova]

Can you be more specific? What plane? Show it on the picture

Answer 2

[Mariana]

[darova]

Sure. Use scatteredInterpolant

p = isosurface(X,Y,Z,val,2);
xx = p.vertices(:,1);
yy = p.vertices(:,2);
zz = p.vertices(:,3);
patch(p,'facecolor','b','edgecolor','none')
F = scatteredInterpolant(yy,zz,xx);             % Function of a plane (Y,Z)

Example of using

x1 = F(90,4)
plot3(x1,90,4,'oy')

Result