How can I matching data from different matrices

Hi!

I have 2 matrices [A], [B], with different dimensions ([A]=4450x10 & [B]=3656x5). The first column in both matrices is the day with numbers 1:365. But some days are missing, not the same days from the two matrices. Also,for each day I have different number of data. For example, in the day 15 in [A] I have 12 lines and in the [B] I have 4 lines. I found the common days:

 Common_days = intersect(A(:,1),B(:,1));

Then, I want to create two files (one for each matrix), which will include only the data with the common days.

Extra, I want to plot in the same graph, the data with the same day from [A] & [B]. The columns I want to plot are [A]=2 & 10, [B]=2&5

Answer 1

[Stephen23]

This is easy using ismember. For simplicity I only show the first column:

>> A = [7;1;7;7;4];
>> B = [7;0;4;4;0];
>> A2 = A(ismember(A,B),:)
A2 =
     7
     7
     7
     4
>> B2 = B(ismember(B,A),:)
B2 =
     7
     4
     4

You can then save A2 and B2 in the text files using dlmwrite.

Answer 2

[Image Analyst]

Use ismember() to find out what rows Common_days are in. Then just use indexing

[ia, ib] = ismember(.......
subsetA = A(rowsToExtract, :);

I can't remember if rowsToExtract is ia or ib but you'll know which it is after you run it.

[Thar]

For the day 8 i have one more lines with data like:

 8  8,98138900000000  2,48300000000000  316,500000000000  8,37422454166667
 8  9,12027800000000  2,42400000000000  319,100000000000  8,38001158333333
 8  9,57027800000000  2,28200000000000  317,500000000000  8,39876158333333
 8  9,74138900000000  2,24400000000000  317,400000000000  8,40589120833333
 8  10,0605560000000  2,19400000000000  318,300000000000  8,41918983333333
 8  10,5166670000000  2,16400000000000  317,800000000000  8,43819445833333

If i write [ia, ib] it keeps the first line of the day only. I want all lines. This happens in all days.

I wrote :

[Common_days,ia,ib] = intersect(A(:,1),B(:,1));

Then C=A(ia,1) D=B(ib,1) and also keep the first line from the data with the same day.

Can I do something else?

Any ideas?