how to delete particular row in given matrix ?

like this matrix

 a=[190.6412 159.7899 0.9991];

 b=[180.1084  166.6349    0.9992
  190.6412  159.7899    0.9991
  179.5966  155.4710    1.0000
  196.5314  166.2689    1.0000];

than the answer should be like this

 c= [180.1084  166.6349    0.9992
     179.5966  155.4710    1.0000
     196.5314  166.2689    1.0000];
i should delete only 'a' matrix from the 'b' matrix and display as 'c' matrix

Answer 1

[Azzi Abdelmalek]

c=setdiff(b,a,'rows')

[Matlab111]

it's showing Error "a and b must have the same number of columns." in my case 'a' matrix will be same but 'b' matrix will get varies.

[Adam]

You should give an example that matches your edge case scenarios then as what you say doesn't seem to make sense.

If a and b have different number of columns then clearly none of the rows of b will be equal to a as you cannot delete just part of a row from a numeric matrix

[Matlab111]

her example:

 a=[190.6412 159.7899 0.9991];
 b=[180.1084  166.6349    0.9992
  190.6412  159.7899    0.9991
  179.5966  155.4710    1.0000
  196.5314  166.2689    1.0000];

here 'a'matrix size will be constant (1x3), but 'b' matrix will get different,it depends on for loop, 'b' will be like 'nx3 matrix'.

[Adam]

Azzi's answer works fine in that case. If it is just number of rows that changes that is fine. Only if number of columns changes do you have a problem which is what your error message suggested is your case.

[Matlab111]

it's showing Error like "a and b must have the same number of columns."

[Adam]

That is odd because they do have the same number of columns and it works fine for me.

[Matt Tearle]

Can you please either show the a and b you have when that error occurs, or do

whos a b

and report the result. As Adam said, if a is 1-by-3 and b is n-by-3, then Azzi's solution should work. If b is n-by-[anything other than 3], then you'd see the error you're seeing.

If b should always have 3 columns, then you most likely have something else causing a problem. If b can have a different number of columns, then you need to explain what behavior you'd like to see.

[Matlab111]

sorry, guys now i'm getting thanks for u r support.

[Image Analyst]

And this works just fine :

a=[190.6412 159.7899 0.9991];
b=[180.1084  166.6349    0.9992
  190.6412  159.7899    0.9991
  150.6412  169.7899    0.9995
  179.5966  155.4710    1.0000
  196.5314  166.2689    1.0000];
c=setdiff(b,a,'rows')

No error whatsoever. Please post the ACTUAL REAL code you are using, not this code that you just did, which works perfectly fine.

[Matt Tearle]

You seem to be saying that the number of columns of b will vary, but above you also said that 'b' will be like 'nx3 matrix', which means that b will always have 3 columns. And the example you keep showing has 3 columns.

So, again, you need to tell us what behavior you expect for b: should b always have 3 columns, or can the number of columns of b change?

Answer 2

[the cyclist]

Here's one way:

tf = ismember(b,a,'rows')
c = b(not(tf),:)

[Matlab111]

it's showing Error "A and S must have the same number of columns." in my case 'a' matrix will be same but 'b'matrix will get varies.