Finding array elements that include a specified combination of values?

2011 4 23
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I have the following problem. I need to match two sets of dates in two separate arrays, but the formats are different (YYYYMM & YYYYMMDD), and in one of the arrays the dates are randomly mixed.
So I'd need a way to refer to specific parts of an element. As I have the correct timeline with YYYYMM dates, the easieast thing would be to somehow require the beginning of the YYYYMMDD element to match YYYYMM?
Thank you so much in advance!

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Andrew Newell
Andrew Newell 2011-4-23

0 个投票

You can extract the parts of the date using
yourDate = '201105';
switch length(yourDate)
case 6
[Y,M] = datevec(yourDate,'yyyymm')
case 8
[Y,M,D] = datevec(yourDate,'yyyymmdd')
otherwise
error('Invalid date string length.')
end
Y =
2011
M =
5
The same sequence with yourDate = '20110514' gives
Y =
2011
M =
5
D =
14

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Anna
Anna 2011-4-24
Thank you for your help, but I'm afraid I don't actually understand your code (and can't make it work). Could you please explain it?
Andrew Newell
Andrew Newell 2011-4-24
Sorry - I was a bit careless transposing my work. I have edited the above answer.
Anna
Anna 2011-4-24
Thank you! I actually managed to find an alternative way to get the job done (a bit more manual work), but I believe I'll need this later.
Andrew Newell
Andrew Newell 2011-4-24
I like helping people who help themselves!
Anna
Anna 2011-5-1
I'm sorry, but I can't get it to work by reading in dateinformation from an array. I believe the trouble is that the dateinformation when it was imported was as an integer or double, so now matlab can't understand it...
I need the original dates in my study, but I just can't get it to work. With Import Wizard I don't get to set the dates, and for some reason I can't get fopen and textscan to work.
Is there a way to read the values as a string, so that i could thereafter convert them to datevectors.
Thank you a million if you have the patience to answer. I'm getting mildly annoyed with myself as it is.
Anna
Anna 2011-5-1
Sorry for having bothered you, I managed to get around the problem by using the following code:
datum1=zeros(601,1);
datum2=zeros(601,1);
datum3=zeros(601,1);
for k=2:601
str= num2str(winners_aboveRF(k,1));
[Y,M,D] = datevec(str,'yyyymmdd');
datum1(k)=Y;
datum2(k)=M;
datum3(k)=D;
end
I know it's not classy, but it works, so I'm happy. If you however would happen to know a more elegant solution I'd be happy to hear it.
Thank you again for all your help!
Andrew Newell
Andrew Newell 2011-5-1
Are you sure that your code works? What do you get for Y and M if you type [Y,M,D] = datevec('201112','yyyymmdd')?

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