Changing the colour of data points on a graph that satisfy a certain criteria

So i basically calculate a probability and for data points that have a probability of say 0.8 i want to change the colour on the graph, what function do i use to do this? i have tried using the set function but dont seem to be able to get it to work

Answer 1

[bym]

There are many ways of doing this. Here is one

clear;clc

x = rand(2000,1);
y = rand(2000,1);
c = hypot(x -.5,sqrt(y)-1.25*y) > .2;
plot(x(c),y(c),'b.',x(~c),y(~c),'r*')
axis square

[Matt]

%=========================================================================% % Searching for Clusters % %=========================================================================% % % % Import Data manually % By Matthew Crouch 26.09.2012 % Import Data Manually

%% Determination of Data

n =300 ; %Number of Stars in the Cluster Field m = 2905; %Number of Stars in the Control Field

D = data; %Reads 2MASS data jmag = D(:,1); %(:,n) reads the nth colomn hmag = D(:,2); k1mag = D(:,3); diffmag = (jmag-k1mag); diffmag2= (jmag-hmag); diffmag3= (hmag-k1mag);

kmag = find(k1mag < 10); % Eliminates any stars with mag greater than 10 mag

Ra5= Arc5(:,9); Dec5=Arc5(:,10); Ra9=Arc9(:,9); Dec9=Arc9(:,10);

Cfjmag = CF(:,1); %2MASS control Field Cfhmag = CF(:,2); Cfkmag = CF(:,3); Cfdiffmag = (Cfjmag - Cfkmag); Cfdiffmag2 = (Cfjmag - Cfhmag); Cfdiffmag3 = (Cfhmag - Cfkmag);

%% Calculating Cluster Probability %%3D Elipsoid

rccm = zeros(n,n); Crccm = zeros(n,m); CNccm = zeros(n,m); Nccm = zeros(m,1); Prob = zeros(n,1);

for i=1:1:n for j=1:1:n; rccm(i,j) = sqrt((0.5*(jmag(i,1)-jmag(j,1)).^2)+((diffmag(i,1)-diffmag(j,1)).^2)+((diffmag2(i,1)-diffmag2(j,1)).^2)); hold on end end

srt = sort(rccm); %Put in value of the 15th star r = transpose(srt(11,1:n)); %Radius of the 11 star

for i=1:1:n; for k=1:1:m; Crccm(i,k) = sqrt((0.5*(jmag(i,1)-Cfjmag(k,1)).^2)+((diffmag(i,1)-Cfdiffmag(k,1)).^2)+((diffmag2(i,1)-Cfdiffmag2(k,1)).^2)); end rcontr = transpose(Crccm); CNccm = (rcontr(:,i)) <= r(i,1); Nccm(i) = sum(CNccm); Prob(i)= 1-((Nccm(i)/10)*(9/81));

    hold on
end

%% Plotting Of Graphs

figure(1) scatter(diffmag,k1mag, 'xk'); set(gca,'YDir','Reverse'); xlabel '(J-K) Magnitude', ylabel 'K Magnitude', title ' Colour Magnitude Diagram around .....'; %Change Cluster Name Where appropriate

figure(2) scatter(diffmag3,diffmag2,'xr');

xlabel '(H-K) Magnitude', ylabel '(J-H) Magnitude', title 'Colour Colour Diagram around .....'

figure(3) scatter(Cfdiffmag,Cfkmag, 'xb'); set(gca,'YDir','Reverse'); xlabel '(J-K) Magnitude', ylabel 'K Magnitude', title ' Colour Magnitude Diagram around .....(Control Field)';

figure(4) scatter(Cfdiffmag3,Cfdiffmag2,'xm');

xlabel '(H-K) Magnitude', ylabel '(J-H) Magnitude', title 'Colour Colour Diagram around ..... (Control Field)'

figure(5) scatter(Ra5,Dec5,'xk'); hold on xlabel 'RAJ200', ylabel 'DECJ2000',

figure(6) scatter(Ra9,Dec9,'xb'); hold on xlabel 'RAJ200', ylabel 'DECJ2000',

Above is a copy of my code. I am trying to identify members that have a probability over 0.8 then colour them red, then values with a prob between 0.6-0.8 another colour etc etc...how do i do this?