Finding a matching pair of vectors between two matrix

I want to find a matching vector present in other matrix.

For example I want to find the index of XL ,XR,XT,XB in A1 matrix

XL=[0.300000000000000,0]
XR=[5.70000000000000,0]
XT=[3,2.70000000000000]
XB=[3,-2.70000000000000]
A1=[0	0
    3	0
    0.300000000000000	0
    0.600000000000000	0
    0.900000000000000	0
    1.20000000000000	0
    1.50000000000000	0
    1.80000000000000	0
    2.10000000000000	0
    2.40000000000000	0
    2.70000000000000	0
    3	3
    3	0.300000000000000
    3	0.600000000000000
    3	0.900000000000000
    3	1.20000000000000
    3	1.50000000000000
    3	1.80000000000000
    3	2.10000000000000
    3	2.40000000000000
    3	2.70000000000000
    6	0
    3.30000000000000	0
    3.60000000000000	0
    3.90000000000000	0
    4.20000000000000	0
    4.50000000000000	0
    4.80000000000000	0
    5.10000000000000	0
    5.40000000000000	0
    5.70000000000000	0
    3	-3
    3	-0.300000000000000
    3	-0.600000000000000
    3	-0.900000000000000
    3	-1.20000000000000
    3	-1.50000000000000
    3	-1.80000000000000
    3	-2.10000000000000
    3	-2.40000000000000
    3	-2.70000000000000
    0	0
    3	0
    0.300000000000000	0
    0.600000000000000	0
    0.900000000000000	0
    1.20000000000000	0
    1.50000000000000	0
    1.80000000000000	0
    2.10000000000000	0
    2.40000000000000	0
    2.70000000000000	0
    3	3
    3	0.300000000000000
    3	0.600000000000000
    3	0.900000000000000
    3	1.20000000000000
    3	1.50000000000000
    3	1.80000000000000
    3	2.10000000000000]

I am using [C,ia,ib] = intersect(XL,A1,'rows') to find the position of XL vector in A1 but its not working. Can anybody suggest how to do

Answer 1

[David Hill]

a=find(ismember(A1,XL,'rows'));
b=find(ismember(A1,XR,'rows'));
c=find(ismember(A1,XT,'rows'));
d=find(ismember(A1,XB,'rows'));

[RAJAN PRASAD]

Thank you very much

Answer 2

[Adam Danz]

Use [Lia,Locb] = ismember(A1,[XL;XR;XT;XB],'rows')

Lia shows which rows of A1 are matches. find(Lia) shows the row numbers of the matches.

Locb shows which variable (XL, XR, XT, XB) were the match.

find(Lia)
%     ans =
%          3
%         21
%         31
%         41
%         44

Locb(Lia)
%     ans =
%          1   % XL
%          3   % XT
%          2   % XR
%          4   % XB
%          1   % XL

From the results above, we see that rows 3,21,31, 41, and 44 are matches to [XL,XT,XR,XB,XL], respectively.

[RAJAN PRASAD]

Thank you

Answer 3

[Steven Lord]

Be careful about the floating point numbers in your arrays. Consider using ismembertol with the ByRows name-value pair.