Problem with datenum usage

Hi

I am trying to use the datenum function of matlab to convert into dates I read through the manual in matlab andhave used

Time = datenum(num2str(time),'yyyymmdd');

which works but when i change it to also register the Hours and Minutes in failed

time = A(:,1);
Time = datenum(num2str(time),'yyyymmddHHMN');
S.Time=Time

DATENUM failed.

Error in SWAN2buoy (line 29)
Time = datenum(num2str(time),'yyyymmddHHMN');

Caused by:
    Error using cnv2icudf (line 131)
  Unrecognized minute format.  Format string: yyyymmddHHMN.`

have to say that I am using datenum to read timeseries from a file i have, and i would like to have it it a full timeseries form The original uploaded date format is

2.010010100300000e+07

thank you

[Andy L]

Minutes should be 'MM' not 'MN'

Answer 1

[Iain]

Its a typo:

'yyyymmddHHMN'

MN should be MM

[George]

Have tried that as well, and its the same fail

Time = datenum(num2str(time),'yyyymmddHHM');

Error using datenum (line 179)
DATENUM failed.

Error in SWAN2buoy (line 29)
Time = datenum(num2str(time),'yyyymmddHHM');

Caused by:
    Error using cnv2icudf (line 131)
    Unrecognized minute format.  Format string: yyyymmddHHM.

[Star Strider]

You deleted the ‘N’ but didn’t replace it with an ‘M’.

Try this:

Time = datenum(num2str(time),'yyyymmddHHMM');

[Michael Haderlein]

As Iain pointed out, there's a typo:

>> datenum('201408081539','yyyymmddHHMM')

ans =

7.3582e+005

You have only one M instead of two.

[George]

The initial format of the date is

x =20100101
   20100101.0030000
   20100101.0100000
   20100101.0130000
   20100101.0200000

I have tried the

   Time = datenum(num2str(x),'yyyymmddHHMM');

but i get the mentioned error

[Star Strider]

Well, the decimal is new.

The format line has to match the data. See if this works:

Time = datenum(num2str(x),'yyyymmdd.HHMM');

[George]

Hello

I tried with the decimal indicator but it does not work either

Time = datenum(num2str(x),'yyyymmdd.HHMM')
Error using datenum (line 179)
DATENUM failed.

Caused by:
    Error using dtstr2dtnummx
    Failed on converting date string to date number.

[Hikaru]

If x is

x =  [20100101;
      20100101.0030000;
      20100101.0100000;
      20100101.0130000;
      20100101.0200000]

Can you tell us what the numbers in the decimal places means? The following

Time = datenum(num2str(x(n)),'yyyymmdd.HHMM');

works for n = 1,3, and 5. But it fails for n = 2 and 4, so I guess it has something to do with the format.

[Iain]

What values do you have in A(:,1) - I want to see the min & max.

[George]

the values after the decimal represent the hours and minutes of the recording

the min is the starting time 20100101.000000 and the end (max) 20101231.180000

I did not upload the whole column so as to save space

[Iain]

Ok, I figured it out.

datenum only works on ONE number at a time. Loop through, one element at a time, and it should work.

[Michael Haderlein]

Time = arrayfun(@(d) datenum(sprintf('%1.6f\n',d),'yyyymmdd.HHMMSS'),x)

[George]

@Michael Haderlein, thank you very much this is working .

may i ask why does datenum fails when a large series of number is given to it?

[Iain]

It fails when two numbers are given to it. I don't know why.

[George]

thank you everybody for your help :) !