datefind

Indices of dates in matrix

Syntax

Indices = datefind(Subset,Superset)

Indices = datefind(___,Tolerance)

Description

Indices = datefind(Subset,Superset) returns a vector of indices to the date numbers in Superset that are present in Subset. If no date numbers match, Indices = [].

Indices = datefind(___,Tolerance) returns a vector of indices to the date numbers in Superset that are present in Subset, plus the optional argument for Tolerance. If no date numbers match, Indices = [].

Examples

Return a Vector of Indices to Date Numbers

This example shows how to return a vector of indices to date numbers.

Superset = datetime(1999,7,1:31); 
Subset = [datetime(1999,7,10) ; datetime(1999,7,20)]; 
Indices = datefind(Subset, Superset, 1)

Indices = 6×1

     9
    10
    11
    19
    20
    21

Input Arguments

Subset — Subset of dates to find matching dates

datetime array | string array | date character vector

Subset of dates to find matching dates in Superset, specified as a matrix using a datetime array, string array, or date character vectors.

Subset and Superset can be either be a datetime array, string array, or date character vectors. These types do not have to match. datefind determines the underlying date to match dates of different data types.

Note

The elements of Subset must be contained in Superset, without repetition. datefind works with non-repeating sequences of dates.

Example: Subset = [datetime(1997,7,10); datetime(1997,7,20)];

To support existing code, datefind also accepts serial date numbers as inputs, but they are not recommended.

Data Types: char | string | datetime

Superset — Superset of dates

datetime array | string array | date character vector

Superset of dates, specified as a matrix of using a datetime array, string array, or date character vectors, whose elements are sought.

Subset and Superset can be either a datetime array, string array, or date character vectors. These types do not have to match. datefind determines the underlying date to match dates of different data types.

Note

The elements of Subset must be contained in Superset, without repetition. datefind works with non-repeating sequences of dates.

Example: Superset = datetime(1997,7,1:31);

To support existing code, datefind also accepts serial date numbers as inputs, but they are not recommended.

Data Types: char | string | datetime

Tolerance — Tolerance for matching dates in Superset

0 (default) | positive integer or duration object

Tolerance for matching dates (+/-) in Superset, specified as a positive integer or duration object.

Data Types: single | double

Output Arguments

Indices — Indices of dates in Superset that are present in Subset

vector

Indices of dates in Superset that are present in Subset (plus or minus the tolerance if defined using the optional argument Tolerance), returned as a vector of indices.

Version History

Introduced before R2006a

R2022b: Serial date numbers not recommended

Although datefind supports serial date numbers, datetime values are recommended instead. The datetime data type provides flexible date and time formats, storage out to nanosecond precision, and properties to account for time zones and daylight saving time.

To convert serial date numbers or text to datetime values, use the datetime function. For example:

t = datetime(738427.656845093,"ConvertFrom","datenum");
y = year(t)

y =

        2021

There are no plans to remove support for serial date number inputs.