how can i draw a circle?

this is my serial data code

clear all; delete(instrfind); s = serial('COM6'); instrfind set(s, 'InputBufferSize', 256); set(s, 'FlowControl', 'none'); set(s, 'BaudRate', 9600); set(s, 'Parity', 'none'); set(s, 'Timeout',1);

disp(get(s,'Name')); prop(1)=(get(s,'BaudRate')); prop(2)=(get(s,'DataBits')); prop(3)=(get(s, 'StopBit')); prop(4)=(get(s, 'InputBufferSize'));

disp(['Port Setup Done!!',num2str(prop)]); fopen(s); instrfind

stopTime = '9/24 21:53'; time = now;

i=1; j=1;

while ~isequal(datestr(now,'mm/DD HH:MM'),stopTime)

 d(i,j)=fscanf(s,'%f')   %reading serial data and putting them in a matrix
 e=d(:,1)'               %values of the first sensor
 f=d(:,end)'             %values of the second sensor 
 subplot(1,2,1);
 plot(e)                 %plotting the values of the first sensor
 grid
 subplot(1,2,2);
 plot(f)                 %plotting the values of the second sensor
 grid

j=j+1; if j==3 % if the index of columns of the matrix is 3

     i=i+1;             %we go to a new line of the matrix we increment the index of lines
     j=1;               %and we put the index of columns to 1
end ;

drawnow end; fclose(s); delete(s);

clear all;

i have serial data coming from two sensors.I'm putting them in a matrix then splitting them in two matrix: e and f. e contains the values of the first sensor and f contains the values of the second sensor. i need to draw two circles, one for each sensor, and i need to color them according to the values in matrix e and f. how can i do it?

[Geoff Hayes]

elie - are you drawing the two circles on the same plot, or on individual subplots? What is the centre for either circle, and the radius for each? Do both e and f represent colour information? (Given that both is just a 1-D vector, how do you expect to use either for colour?)

[marc kahwaji]

on the same plot

[marc kahwaji]

the centers and the radius i don't care about the radius and i don't care about the position i'm receiving data between 0 and 255 when i receive 0 the two circles must be colored as blue when the value changes to 100 (for example ) the color converge towords orange ect

Answer 1

[Geoff Hayes]

elie - since you do not care about the centres of the circles or the radius for each (but you will when you want to draw them within your figure), you can check out the draw filled circle question which contains a couple of examples.

One uses the rectangle function which can be used to draw two circles, one within the other, as follows

 figure;
 hold on;

 % draw a red circle with centre at (2.5,2.5) with a radius of 2.5
 redColour = [1 0 0];
 rectangle('Position',[0 0 5 5],'Curvature',[1 1],'EdgeColor', ...
     redColour,'FaceColor', redColour)

 % draw a blue circle with centre at (2.5,2.5) with a radius of 1.5
 blueColour = [0 0 1];
 rectangle('Position',[1 1 3 3],'Curvature',[1 1],'EdgeColor',  ...
     blueColour,'FaceColor', blueColour)

 axis equal

Note that you will have to define your mapping from a number to a colour i.e. if received data is 0, then the colour is blue, the three element vector [0 0 1]. If the received data is 100, then the colour is orange [255 165 0]./255. (Note that this final example shows that your colour vectors must have all three values in the range of [0,1].

Try the above and see what happens!

[marc kahwaji]

thanks

Answer 2

[Chad Greene]

Here's a simple solution: http://www.mathworks.com/matlabcentral/fileexchange/45952-circle-plotter