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From: bjornnak on 7 May 2010 10:16
Hi,

I'm a new user of Matlab, so I guess this one should be pretty easy.

I have a dated time-series (yyyy-mm-dd) and I want to convert the
dates to Matlab serial dates.

time = datenum(dates,'yyyy-mm-dd')

This doesn't seem to work, and I get different errors when I try to
tweak the command and inputs.

First, the dates are in a cell array (icon with { } brackets), and it
seems Matlab prefers it in string (char) format, but I'm not too sure
about this.

I have no problem getting a single date, using datenum(dates{1}) but
when I try to more than one date it tells me Index exceeds matrix
dimensions.

The array is 10183x1, so shouldn't the proper input be datenum(dates{:,
1}) [this means, get the entire column 1, right?)

I want the results to end up in the 'time' vector, and I've tried
different things to solve to matrix dimension issue: 1. creating an
empty 10183x1 vector, 2. creating a completely empty 'time' vector,
and 3. defining it when running the datenum command, as in row 3 of
this post. Nothing works.

If the issue lies in that my dates are in a cell array rather than in
a char, I'm having problems here to since I cannot find a way that
simply lets me convert the array to char.

Any help is very welcolme!

/ Björn
From: us on 7 May 2010 15:41
bjornnak <bjorn.r.jonsson(a)gmail.com> wrote in message <8134dbc3-b6b9-4e95-b327-3e02332ab7de(a)k29g2000yqh.googlegroups.com>...
> Hi,
>
> I'm a new user of Matlab, so I guess this one should be pretty easy.
>
> I have a dated time-series (yyyy-mm-dd) and I want to convert the
> dates to Matlab serial dates.
>
> time = datenum(dates,'yyyy-mm-dd')
>
> This doesn't seem to work, and I get different errors when I try to
> tweak the command and inputs.
>
> First, the dates are in a cell array (icon with { } brackets), and it
> seems Matlab prefers it in string (char) format, but I'm not too sure
> about this.
>
> I have no problem getting a single date, using datenum(dates{1}) but
> when I try to more than one date it tells me Index exceeds matrix
> dimensions.
>
> The array is 10183x1, so shouldn't the proper input be datenum(dates{:,
> 1}) [this means, get the entire column 1, right?)
>
> I want the results to end up in the 'time' vector, and I've tried
> different things to solve to matrix dimension issue: 1. creating an
> empty 10183x1 vector, 2. creating a completely empty 'time' vector,
> and 3. defining it when running the datenum command, as in row 3 of
> this post. Nothing works.
>
> If the issue lies in that my dates are in a cell array rather than in
> a char, I'm having problems here to since I cannot find a way that
> simply lets me convert the array to char.
>
> Any help is very welcolme!
>
> / Björn

one of the solutions

d={ % <- a CELL of CHAR strings...
'2000-01-01'
'2001-02-02'
'2010-12-31'
};
dt=datenum(d,'yyyy-mm-dd')
%{
% dt =
730486
730884
734503
%}
% check
datestr(dt)
%{
01-Jan-2000
02-Feb-2001
31-Dec-2010
%}

us
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