Extracting index of specified date from datetime array

Let us say that I have a datetime array which has dates that goes like these:

'2015-05-03 23:59:56'

'2015-05-03 23:59:56'

'2015-05-03 23:59:56'

'2015-05-03 23:59:56'

'2015-05-03 23:59:57'

'2015-05-03 23:59:57'

'2015-05-03 23:59:57'

'2015-05-03 23:59:57'

'2015-05-03 23:59:57'

'2015-05-03 23:59:57'

'2015-05-03 23:59:57'

'2015-05-03 23:59:57'

Now, I would like to know the indices of one certain element, say {'2015-05-03 23:59:57'}. How can I get that?

I tried with example given in https://in.mathworks.com/help/finance/datefind.html, but even for the example given there is not getting executed in my pc. It is giving an error ‘Undefined function 'datefind' for input arguments of type 'double'.’. I suspect that it may be due to not having the proper toolbox. The toolbox that I am having are:

Curve Fitting Toolbox, Parallel Computing Toolbox, Partial Differential Equation Toolbox, Signal Processing Toolbox and Symbolic Math Toolbox

Thanks in advance.

Answer 1

[Walter Roberson]

S = datetime({'2015-05-03 23:59:56'
'2015-05-03 23:59:56'
'2015-05-03 23:59:56'
'2015-05-03 23:59:56'
'2015-05-03 23:59:57'
'2015-05-03 23:59:57'
'2015-05-03 23:59:57'
'2015-05-03 23:59:57'
'2015-05-03 23:59:57'
'2015-05-03 23:59:57'
'2015-05-03 23:59:57'
'2015-05-03 23:59:57'})

S = 12×1 datetime array
   03-May-2015 23:59:56
   03-May-2015 23:59:56
   03-May-2015 23:59:56
   03-May-2015 23:59:56
   03-May-2015 23:59:57
   03-May-2015 23:59:57
   03-May-2015 23:59:57
   03-May-2015 23:59:57
   03-May-2015 23:59:57
   03-May-2015 23:59:57
   03-May-2015 23:59:57
   03-May-2015 23:59:57

probe = datetime('2015-05-03 23:59:57')

probe = datetime
   03-May-2015 23:59:57

find(S == probe)

ans = 8×1

5 6 7 8 9 10 11 12

[matteo franchi]

% I have this kind of result, can anyone help me?

[Stephen23]

@matteo franchi: it is clear that the date/time values do not exactly match each other. So you first need to decide if you want to find:

• the single pair of closest date/time values?
• all date/time values that are within a particular range/tolerance?
• some other criteria...

[Walter Roberson]

Remember that when you use == that everything down to nanoseconds (or further) must be identical.