how to choose right index

Dear All,

 I have this matrix X and this is the index for it. I want to take the row with 1 1 index to empty and plot the remind points, but I got wrong

Y =[1.7797    1.3341
    1.5067    0.5390
    1.0709    1.0732
    1.2872    1.0745
    0.3687    1.4166
    0.4112    0.2333
    1.4512    0.8961
    1.9749    1.6645];

idx =[0     1
     0     1
     1     1
     1     1
     0     1
     0     0
     1     1
     0     0];
m=8;
for i=1:1:m
        if idx(i,1:1:end)==1
             Y(i,:)=[]
             end
       m=size(Y,1)
     end
          plot(Y(:,1),Y(:,2),'.r');

I know my problem with the if condition, I don't know who to write it correct. Can anyone help me please.

Regards, imola

regards

[Geoff Hayes]

Imola - please provide some context surrounding your code. What is the relationship between the first block and the second block? Add some comments so that we can get an idea of what it is you are trying to accomplish.

[imola]

sorry Geoff,

 I change the question hopefully make it simple, I'm stuck here  

if idx(i,1:1:end)==1

I think it is wrong, I want to generalize this formula to dim>2 if it succeed here.

Thanks for replying.

Regards

[Image Analyst]

You say "I have this matrix X" - what matrix X???? And if idx(i,1:1:end)==1 gives a vector. I think you want to use all().

Answer 1

[Image Analyst]

Perhaps you want this:

clc;
Y =[1.7797    1.3341
  1.5067    0.5390
  1.0709    1.0732
  1.2872    1.0745
  0.3687    1.4166
  0.4112    0.2333
  1.4512    0.8961
  1.9749    1.6645];

idx =[0     1
  0     1
  1     1
  1     1
  0     1
  0     0
  1     1
  0     0];
[rows, columns] = size(idx)
rowsToKeep = false(rows, 1);
for row=1:1:m
  allOnes = all(idx(row, :));
  if ~allOnes
    rowsToKeep(row) = true;
  end
end
rowsToKeep
extractedY = Y(rowsToKeep, :);
plot(extractedY(:,1), extractedY(:,2), 'r.-', 'MarkerSize', 20);
grid on;

[imola]

Dear,

thank you very much for your answer. you really saved me. I understood what you did but I want to be sure so I can use the commends in future, so could you please explain it to me.

Many thanks,

Imola.

Answer 2

[Thorsten]

 Y = Y(sum(idx, 2) ~= 2, :);
 plot(Y(:,1), Y(:,2), '.r')