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Reading/Finding data withing column
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I have loaded my data into matlab using the uiiport(mydata.txt). It consists of 4 columns, like so:
(0 0 0 0)
(1 0 0 25)
(1 1 0 74)
(1 1 1 122)
(2 0 0 200)
....
I would like to program a way that I can ask for a number as mydata(column1,column2,column3), and have it give me the corresponding number in column 4. For example:
constants = uiimport(mydata.txt)
SomeCommand(1,1,0);
=
74
Is there a simple way to do this? It would also be nice to be able to label the columns with their meaning in the variable editor, but it's not really necessary.
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Respuestas (3)
Jonathan Sullivan
el 22 de Mayo de 2013
[~,ind] = ismember([1 1 0],constants(1:3,:),'rows');
constants(ind,4)
3 comentarios
Azzi Abdelmalek
el 23 de Mayo de 2013
constants=[0 0 0 0
1 0 0 25
1 1 0 74
1 1 1 122
0 0 0 200]
a=constants(:,1:3)
[idx,idx]=ismember(a,[1 1 0],'rows')
out=constants(logical(idx),4)
0 comentarios
Iain
el 23 de Mayo de 2013
constants(find( (constants(:,1) == 1st) & (constants(:,2) == 2nd) & (constants(:,3) == 3rd)),4)
This:
1. Compares each of the first 3 columns against what you supply as 1st, 2nd and 3rd (constants(:,1) == x), takes the "and" of those logical results "&", and returns a single column containing true where all three match, and false elsewhere.
2. find, then gets the row number of EACH true.
3. It then retuns the correct elements of column #4. - If there are none, it returns an empty.
5 comentarios
Iain
el 24 de Mayo de 2013
It might make a difference, but its probably not worth worrying about unless you have to read in the file(s) lots.
constants has come out as a structure, with a single field with the name "Constant0x2810x29".
Where I have put constants, you should put constants.Constant0x2810x29.
Constant0x2810x29 will probably change from file to file, so you may need something like this:
fn = fieldnames(constant); % Gets a list of the fields (in code)
mydata = getfield(constant,fn{1}); % Gets the 1st field from constant and puts it in mydata.
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