how to delete particular row in given matrix ?

2014 11 4
2 个回答
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更新时间：2014 11 4
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0 个投票

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

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 采纳的回答

Azzi Abdelmalek
Azzi Abdelmalek 2014-11-4
编辑：Azzi Abdelmalek 2014-11-4

0 个投票

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

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Matlab111
Matlab111 2014-11-4
编辑：Matlab111 2014-11-4
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
Adam 2014-11-4
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
Matlab111 2014-11-4
编辑：Matlab111 2014-11-4
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
Adam 2014-11-4
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
Matlab111 2014-11-4
it's showing Error like "a and b must have the same number of columns."
Adam
Adam 2014-11-4
That is odd because they do have the same number of columns and it works fine for me.
Matt Tearle
Matt Tearle 2014-11-4
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
Matlab111 2014-11-4
编辑：Matlab111 2014-11-4
sorry, guys now i'm getting thanks for u r support.
Image Analyst
Image Analyst 2014-11-4
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
Matt Tearle 2014-11-4
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?

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更多回答（1 个）

the cyclist
the cyclist 2014-11-4

0 个投票

Here's one way:
tf = ismember(b,a,'rows')
c = b(not(tf),:)

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Matlab111
Matlab111 2014-11-4
编辑：Matlab111 2014-11-4
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.

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