How to find data from different matrix accordance to a treaty

Hi all! Please help!

I have two matrix with different dimensions and I want to plot some data from first and some data from the second accordance to a treaty. First matrix is:

 8  10,0605560000000  2,19400000000000  318,300000000000  8,41918983333333
8  10,5166670000000  2,16400000000000  317,800000000000  8,43819445833333
9  8,05666700000000  3,13100000000000  320,500000000000  9,33569445833333
9  9,05444400000000  2,44200000000000  321,700000000000  9,37726850000000
9  10,0169440000000  2,19000000000000  320,500000000000  9,41737266666667
9  10,4705560000000  2,15500000000000  320,700000000000  9,43627316666667
10  10,8983330000000  2,15300000000000  345,600000000000  10,4540972083333
10  12,6902780000000  2,73300000000000  334,600000000000  10,5287615833333
11  8,00638900000000  3,15900000000000  306,700000000000  11,3335995416667
11  8,71111100000000  2,59000000000000  306,800000000000  11,3629629583333
11  9,05722200000000  2,42000000000000  306,500000000000  11,3773842500000
11  9,19666700000000  2,36600000000000  306,800000000000  11,3831944583333
11  9,92138900000000  2,18400000000000  305,800000000000  11,4133912083333
11  10,2961110000000  2,14300000000000  307,900000000000  11,4290046250000
14  9,37944400000000  2,27200000000000  320,200000000000  14,3908101666667
14  9,55444400000000  2,22400000000000  318,300000000000  14,3981018333333
16  10,9255560000000  2,08300000000000  343,600000000000  16,4552315000000
16  12,8616670000000  2,71900000000000  334                  16,5359027916667
17  8,00500000000000  3,05900000000000  315,200000000000  17,3335416666667
17  8,53833300000000  2,61400000000000  313,300000000000  17,3557638750000
17  8,88444400000000  2,42200000000000  315,300000000000  17,3701851666667
17  9,02444400000000  2,35900000000000  312                  17,3760185000000

The second matrix is:

 7  13,2502780000000  3,32706700000000  216,616500000000  7,55209491666667
8  10,1752780000000  2,18026800000000  318,552446000000  8,42396991666667
8  10,3502780000000  2,16782900000000  311,812207000000  8,43126158333333
8  10,5597220000000  2,16194100000000  322,855557000000  8,43998841666667
8  10,7558330000000  2,16519900000000  326,371126000000  8,44815970833333
8  10,9433330000000  2,17629400000000  322,198083000000  8,45597220833333
8  11,1275000000000  2,19501000000000  326,766784000000  8,46364583333333
9  9,64222200000000  2,25401500000000  329,669721000000  9,40175925000000
9  9,83694400000000  2,21544900000000  331,429023000000  9,40987266666667
9  10,2577780000000  2,16408400000000  334,167393000000  9,42740741666667
9  12,6952780000000  2,75292100000000  319,587539000000  9,52896991666667
10  13,9086110000000  4,37976100000000  197,899461000000  10,5795254583333
11  7,75722200000000  3,46624100000000  197,799138000000  11,3232175833333
11  8,25666700000000  2,90756100000000  219,678581000000  11,3440277916667
11  9,05055600000000  2,42024800000000  250,809758000000  11,3771065000000
11  11,4597220000000  2,21250200000000  292,723255000000  11,4774884166667
12  8,76305600000000  2,54592200000000  230,458298000000  12,3651273333333
12  8,97388900000000  2,44217200000000  227,875052000000  12,3739120416667
12  9,20166700000000  2,35097600000000  270,648275000000  12,3834027916667
12  9,43805600000000  2,27545700000000  287,292242000000  12,3932523333333
12  9,66972200000000  2,21784400000000  263,244168000000  12,4029050833333
13  11,0405560000000  2,12788200000000  342,286940000000  13,4600231666667
13  12,0719440000000  2,35468200000000  333,077368000000  13,5029976666667
13  12,2405560000000  2,42261700000000  339,119709000000  13,5100231666667
14  11,3652780000000  2,15610300000000  247,436415000000  14,4735532500000
14  11,5663890000000  2,19384600000000  279,951366000000  14,4819328750000
14  11,7661110000000  2,24181400000000  270,288234000000  14,4902546250000
14  11,9855560000000  2,30795500000000  241,350318000000  14,4993981666667
16  12,4169440000000  2,44870200000000  232,896976000000  16,5173726666667
16  13,1205560000000  2,92910800000000  238,656026000000  16,5466898333333
16  13,3555560000000  3,17478800000000  214,067701000000  16,5564815000000
16  13,8230560000000  3,88352000000000  218,751504000000  16,5759606666667
17  7,64722200000000  3,51006600000000  213,658530000000  17,3186342500000
17  7,87444400000000  3,20061400000000  194,116288000000  17,3281018333333

First column is the day. I want to plot for the same day from two matrix the columns 4&5.

Thank you.

[Geoff Hayes]

Thodoris - rather than pasting your two matrices into your question body (instead attach as text files) why not just describe them. What are the dimensions of each matrix? What do the columns mean? How do you expect to plot all of the data from columns four and five for the same day? For example, if the day is 8, what do you want to do?

[Thar]

For example, if the day is 8, I'd like to take the data from columns 4&5 from two matrices and plot. However, the data from two matrices may not have the same dimensions. The first matrix may have 7 lines and the second matrix 16 lines. Also, the one matrix may not have some days.

Answer 1

[wil]

You can use find() on the first column to get the row indexes of the rows you want to plot.

Say your matrices are A and B, then you can do

idx_a = find(A(:,1) == day);
idx_b = find(B(:,1) == day);

toplot_a = A(idx_a,4:5);
toplot_b = B(idx_b,4:5);

The toplot variables will by n-by-2 matrices of your values for that day (from the 4th and 5th column), and empty if there are no values for that day.

Wil

[Thar]

my matrices have days 1:365.Some days are missing. If i write

 for i=1:365
     day=i;
     idx_a = find(A(:,1) == day);
     idx_b = find(B(:,1) == day);
 end

i take the message:

Index exceeds matrix dimensions.

[wil]

The only indexing is in A(:,1) and B(:,1), but there shouldn't be a problem with that if both A and B are non-empty (since they will at least be 1-by-1).

I did notice a typo in my original code:

toplot_b = A(idx_b,4:5);

should actually be

toplot_b = B(idx_b,4:5);

so if you copied that, this could be the course of the indexing error. I have corrected the original code sample now as well.