Hi,
for your matrix A:
>> A = [ 1 23 240;2 22 100;2 44 900;1 33 800]
A =
1 23 240
2 22 100
2 44 900
1 33 800
to get the data splitted without for loop use:
>> A1 = [A(A(:,1)==1,2),A(A(:,1)==1,3)]
A1 =
23 240
33 800
>> A2 = [A(A(:,1)==2,2),A(A(:,1)==2,3)]
A2 =
22 100
44 900
Now you have splitted data which you can plot however you want:
>> plot(A1(:,1),A1(:,2),'r')
>> hold on
>> plot(A2(:,1),A2(:,2),'b')
which gives:

Best regards
Stephan