problem with scatter/bubble plot

4 次查看（过去 30 天）
germ
germ 2011-12-28
hi,
i have created a vector containing coordinates of a circle in a matrix.
i want to display these locations as dots in a plot.further i want to color these dots in a clockwise increasing color scheme. i have written a code but experienced a problem : the color vector which i created does not seem to be mapped linearly to my location points
code:
matrix = ones(512,512);
mittelpunkt_x = 256;
mittelpunkt_y = 256;
radius = 33;
for i=1:size(matrix,1)
for j = 1:size(matrix,2)
matrix(i,j) = norm([i j]-[mittelpunkt_x,mittelpunkt_y],2);
if matrix(i,j)<=radius
matrix(i,j)=0;%10;
elseif matrix(i,j)<radius+1 && matrix(i,j)>radius
matrix(i,j)=1;
else
matrix(i,j)=0;
end
end
end
b=0.00490196078
[r,c]=find(matrix==1);
color=[b:b:1];
y=[r c];
scatter(r,c,50,color,'filled')
i hope someone can help me with this
g3rm9

请先登录，再回答此问题。

采纳的回答

bym
bym 2011-12-28
something like this?
t = 0:pi/6:2*pi
t(13)=[];
x = cos(t);
y = sin(t);
c = spring(12);
scatter(x,y,[],c,'filled')
  4 个评论
显示 2更早的评论
germ
germ 2011-12-29
thank you alot !
my final code is :
t = 0:pi/30:2*pi
t(60)=[];
x = cos(t);
y = sin(t);
c = jet(60);
z = zeros(60,3);
z(1,:)=[1 0 0];
for j=1:60;
scatter(x,y,[],circshift(c, [-j,0]),'filled')
axis equal;
F(j) = getframe;
end
movie(F,2)
the only thing i wonder is why the 17th point seems to be missing
bym
bym 2011-12-29
second line should be:
t(61) = [ ];

请先登录，再进行评论。

更多回答（1 个）

the cyclist
the cyclist 2011-12-28
I'm not sure I understand what the problem is. When I run your code, I see a circle with varying color going around it, which I assume is what you want. It may not look like a circle, because the displayed axes do not have equal aspect ratio. You may want to put the following code after your scatter() command:
>> axis equal
>> axis square
If that is not what you mean, then you will need to be more explicit by what "mapped linearly to my location points" means.
  1 个评论
germ
germ 2011-12-28
thank you for the quick reply !
yes i may have not been very explicit with my question.
when i run the upper code i see the colored circle.what i want is a smooth flow from ie: yellow to red. through the whole circle. in the current plot the colorvariation from yellow to red only reaches from the 1 point to half of the circle then the color decreases in the second part ending with the 1 and last point being the same color.
at the current state i have modified my code to :
matrix = ones(50,50);
mittelpunkt_x = 25;
mittelpunkt_y = 25;
radius = 11;
for i=1:size(matrix,1)
for j = 1:size(matrix,2)
matrix(i,j) = norm([i j]-[mittelpunkt_x,mittelpunkt_y],2);
if matrix(i,j)<=radius
matrix(i,j)=0;%10;
elseif matrix(i,j)<radius+1 && matrix(i,j)>radius
matrix(i,j)=1;
else
matrix(i,j)=0;
end
end
end
%figure
%imshow(matrix,[0 10]);
[r,c]=find(matrix==1);
farbe=rand(1,60);
R = zeros(60,1);
G = zeros(60,1);
B = zeros(60,1);
R(:,1)=1;
G0=[1/60:1/60:1];
G=G0';
R(20,1)=0;
G(20,1)=0;
B(20,1)=0;
RGB = [R G B];
y=[r c]; %r=x-koordinate c=y-koordinate
z=matrix(:);
figure
scatter(r,c,50,RGB,'filled')
axis equal
axis square
R2 = R([60 1:59],1);
G2 = G([60 1:59],1);
B2 = B([60 1:59],1);
RGB2=[R2 G2 B2];
figure
scatter(r,c,50,RGB2,'filled')
axis equal
axis square
R3 = R2([60 1:59],1);
G3 = G2([60 1:59],1);
B3 = B2([60 1:59],1);
RGB3=[R3 G3 B3];
figure
scatter(r,c,50,RGB3,'filled')
R4 = R3([60 1:59],1);
G4 = G3([60 1:59],1);
B4 = B3([60 1:59],1);
RGB4=[R4 G4 B4];
figure
scatter(r,c,50,RGB4,'filled')
axis equal
axis square
for i want the circle to have 60 locations imitating a clock .
the second change i made is that i generated multiple plots cause i want to do a animation of the circle. means making it turn(i'm still not sure how to realize this but am working on it)
i hope you can imagine what i mean :)

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Annotations 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by