MATLAB: Plotting multilines with multi colours

3d plotscolorlineplot

I have a very big matrix called Vertices (100000 X 6 matrix) First 3 columns have x y z points. last 3 columns have the colour of that point. for eg first 2 rows are

7645   383   3    49  47  39
7649   382   4    38  37  31

I need to plot all the points with the defined colors.

for ii = 1:1000
      plot3(Vertices(ii,1), Vertices(ii,2), Vertices(ii,3), 'color',[Vertices(ii,4)/255, Vertices(ii,5)/255, Vertices(ii,6)/255], 'Marker', '.');
        hold on;
  end

This works. I have tried for first 1000 element. But since my matrix size is very large. It take a lot of time if i plot using loop. Is there any easy way to plot this?

Best Answer

scatter3(Vertices(:,1), Vertices(:,2), Vertices(:,3),1, Vertices(:, 4:6)/255, 'filled'); % 3D scatter plot

Related Solutions

MATLAB: Common color range for surface.m and surf.m for subplots

The first problem is quite simple. You just need to specify the limit of the color axis. If you set the same limits for all axes, then, value at the same level will have the same color. Try this code

[X,Y] = meshgrid(linspace(-1/2*pi,1/2*pi));
Z1 = cos(X).*cos(Y);
Z2 = 2*cos(X).*cos(Y);
% 2D figure

figure;
subplot(1,2,1);
surface(X,Y,Z1,'EdgeColor','flat','LineStyle','none','FaceColor','flat');
caxis([0 2]) % <---- this line



subplot(1,2,2);
surface(X,Y,Z2,'EdgeColor','flat','LineStyle','none','FaceColor','flat');
caxis([0 2]) % <---- this line
% 3D figure

figure;
subplot(1,2,1);
surf(X,Y,Z1,'EdgeColor','flat','LineStyle','none','FaceColor','flat');
caxis([0 2]) % <---- this line
subplot(1,2,2);
surf(X,Y,Z2,'EdgeColor','flat','LineStyle','none','FaceColor','flat');
caxis([0 2]) % <---- this line

The second problem is a bit complicated. You need to create your own colormap such that the color appears to be discrete. Try the following code. I divided the interval [0,2] into 5 portions. This code used random colors for each portion, you can define your own RGB colors equal to the number of portions.

[X,Y] = meshgrid(linspace(-1/2*pi,1/2*pi));
Z1 = cos(X).*cos(Y);
Z2 = 2*cos(X).*cos(Y);
% define the custom discrete colormap
color_edges = [0 0.4 0.8 1.2 1.6 2.0]; % 5 intervals
colors = rand(5,3); % define as many rgb colors as the number of intervals
resolution_colormap = 100;
t = linspace(min(color_edges), max(color_edges), resolution_colormap);
c_idx = discretize(t, color_edges);
c_map = colors(c_idx, :);
% 2D figure
figure;
subplot(1,2,1);
surface(X,Y,Z1,'EdgeColor','flat','LineStyle','none','FaceColor','flat');
colormap(c_map);
caxis([0 2])
subplot(1,2,2);
surface(X,Y,Z2,'EdgeColor','flat','LineStyle','none','FaceColor','flat');
colormap(c_map);
caxis([0 2])
% 3D figure
figure;
subplot(1,2,1);
surf(X,Y,Z1,'EdgeColor','flat','LineStyle','none','FaceColor','flat');
colormap(c_map);
caxis([0 2])
subplot(1,2,2);
surf(X,Y,Z2,'EdgeColor','flat','LineStyle','none','FaceColor','flat');
colormap(c_map);
caxis([0 2])

MATLAB: Verification of system characteristics

% FOR TIME VARITANT OR INVARIANT
clc
clear all
close all
t=-5:0.001:5
l=length(t)
for i=1:l
    if t(i)>=0
        x1(i)=1;
        
    else x1(i)=0;
    end
end
x2=cos(pi*t)
x3=cos(pi*(t-2))
y1=x1.*x2
y2=x1.*x3
subplot(4,1,1)
plot(t,x1)
xlabel('t')
ylabel('x1')
title('for x1')
grid on
gtext('1841014009')
subplot(4,1,2)
plot(t,y1)
xlabel('t')
ylabel('y1')
title('for y1')
grid on
gtext('1841014009')
subplot(4,1,3)
plot(t,x2)
xlabel('t')
ylabel('x2')
title('for x2')
grid on
gtext('1841014009')
subplot(4,1,4)
plot(t,y2)
xlabel('t')
ylabel('y2')
title('for y2')
grid on
gtext('1841014009')
if round(y1)==round(y2)
    disp('time invariant');text(-2,-0.5, ('System Is Time Invariant'));
    
else disp('time variant');text(-2,-0.5, ('System Is Time Variant'))
end
% FOR LINEARITY TEST
clc
clear all
close all
t=-4:0.001:5
l=length(t)
for i=1:l
    if t(i)>=0
        x1(i)=1;
        
    else x1(i)=0;
    end
end
 
for i=1:l
if t(i)>=1
    x2(i)=1;
    
else x2(i)=0;
end
end
 
a1=2
a2=3
 
y1=a1.*x1.*cos(pi*t)
y2=a2.*x2.*cos(pi*(t-1))
 
y=((a1.*x1)+(a2.*x2)).*cos(pi*t)
 
y3=y1+y2;
 
subplot(4,1,1)
plot(t,y)
title('for y')
xlabel('t')
ylabel('y')
grid on
gtext('1841014009')
subplot(4,1,2)
plot(t,y1)
title('for y1')
xlabel('t')
ylabel('y1')
grid on
gtext('1841014009')
 
subplot(4,1,3)
plot(t,y2)
title('for y2')
xlabel('t')
ylabel('y2')
grid on
gtext('1841014009')
  
subplot(4,1,4)
plot(t,y3)
title('for y3')
xlabel('t')
ylabel('y3')
grid on
gtext('1841014009')
 
if round(y)==round(y3)
    disp('system is linear');
    text(-2,-0.5, ('System Is Linear'));
    
else disp('system is non linear');
    text(-2,-0.5, ('System Is Non-Linear'));
end
% FOR STABILITY TEST
clc
clear all
close all
t=0:0.01:10
l=length(t)
for i=1:l
    if t(i)>=0
        x(i)=1;
        
    else x(i)=0;
    end
end
 
y=exp(-2*t).*x
c=0
for i=1:l-1
    if (y(i)>y(i+1))
        c=c+1;
    end
end
 
subplot(2,1,1)
plot(t,x)
title('for x')
xlabel('t')
ylabel('x')
grid on
gtext('1841014009')
subplot(2,1,2)
plot(t,y)
title('for y')
xlabel('t')
ylabel('y')
grid on
gtext('1841014009')
if(c~=0)
    disp('system is stable');
    text(2,0.5, ('System Is Stable'));
else 
    disp('system is unstable');
    text(2,0.5, ('System Is Untable'));
end

Best Answer

Related Solutions

MATLAB: Common color range for surface.m and surf.m for subplots

MATLAB: Verification of system characteristics

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