Files
file	datetime.hpp
	DateTime column APIs.

Enumerations
enum class	cudf::datetime::rounding_frequency : int32_t { DAY , HOUR , MINUTE , SECOND , MILLISECOND , MICROSECOND , NANOSECOND }
	Fixed frequencies supported by datetime rounding functions ceil, floor, round.

Functions
std::unique_ptr< cudf::column >	cudf::datetime::last_day_of_month (cudf::column_view const &column, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
	Computes the last day of the month in datetime type and returns a TIMESTAMP_DAYS cudf::column. More...

std::unique_ptr< cudf::column >	cudf::datetime::day_of_year (cudf::column_view const &column, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
	Computes the day number since the start of the year from the datetime and returns an int16_t cudf::column. The value is between [1, {365-366}]. More...

std::unique_ptr< cudf::column >	cudf::datetime::add_calendrical_months (cudf::column_view const &timestamps, cudf::column_view const &months, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
	Adds or subtracts a number of months from the datetime type and returns a timestamp column that is of the same type as the input `timestamps` column. More...

std::unique_ptr< cudf::column >	cudf::datetime::add_calendrical_months (cudf::column_view const &timestamps, cudf::scalar const &months, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
	Adds or subtracts a number of months from the datetime type and returns a timestamp column that is of the same type as the input `timestamps` column. More...

std::unique_ptr< cudf::column >	cudf::datetime::is_leap_year (cudf::column_view const &column, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
	Check if the year of the given date is a leap year. More...

std::unique_ptr< cudf::column >	cudf::datetime::days_in_month (cudf::column_view const &column, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
	Extract the number of days in the month. More...

std::unique_ptr< cudf::column >	cudf::datetime::extract_quarter (cudf::column_view const &column, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
	Returns the quarter of the date. More...

std::unique_ptr< cudf::column >	cudf::datetime::ceil_datetimes (cudf::column_view const &column, rounding_frequency freq, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
	Round datetimes up to the nearest multiple of the given frequency. More...

std::unique_ptr< cudf::column >	cudf::datetime::floor_datetimes (cudf::column_view const &column, rounding_frequency freq, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
	Round datetimes down to the nearest multiple of the given frequency. More...

std::unique_ptr< cudf::column >	cudf::datetime::round_datetimes (cudf::column_view const &column, rounding_frequency freq, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
	Round datetimes to the nearest multiple of the given frequency. More...

Detailed Description

Function Documentation

◆ add_calendrical_months() [1/2]

std::unique_ptr<cudf::column> cudf::datetime::add_calendrical_months	(	cudf::column_view const &	timestamps,
		cudf::column_view const &	months,
		rmm::mr::device_memory_resource *	mr = `rmm::mr::get_current_device_resource()`
	)

Adds or subtracts a number of months from the datetime type and returns a timestamp column that is of the same type as the input timestamps column.

For a given row, if the timestamps or the months column value is null, the output for that row is null. This method preserves the input time and the day where applicable. The date is rounded down to the last day of the month for that year, if the new day is invalid for that month.

Example:
timestamps = [5/31/20 08:00:00, 5/31/20 00:00:00, 5/31/20 13:00:00, 5/31/20 23:00:00,
              6/30/20 00:00:01, 6/30/20 14:12:13]
months     = [1               , -1              , -3              , -15             ,
              -1              , 1]
r = add_calendrical_months(timestamp_column, months_column)
r is [6/30/20 08:00:00, 4/30/20 00:00:00, 2/29/20 13:00:00, 2/28/19 23:00:00,
      5/30/20 00:00:01, 7/30/20 14:12:13]

Exceptions

cudf::logic_error	if `timestamps` datatype is not a TIMESTAMP or if `months` datatype is not INT16 or INT32.
cudf::logic_error	if `timestamps` column size is not equal to `months` column size.

Parameters

timestamps	cudf::column_view of timestamp type
months	cudf::column_view of integer type containing the number of months to add
mr	Device memory resource used to allocate device memory of the returned column

Returns: cudf::column of timestamp type containing the computed timestamps

◆ add_calendrical_months() [2/2]

std::unique_ptr<cudf::column> cudf::datetime::add_calendrical_months	(	cudf::column_view const &	timestamps,
		cudf::scalar const &	months,
		rmm::mr::device_memory_resource *	mr = `rmm::mr::get_current_device_resource()`
	)

Adds or subtracts a number of months from the datetime type and returns a timestamp column that is of the same type as the input timestamps column.

For a given row, if the timestamps value is null, the output for that row is null. A null months scalar would result in an all null column. This method preserves the input time and the day where applicable. The date is rounded down to the last day of the month for that year, if the new day is invalid for that month.

Example:
timestamps = [5/31/20 08:00:00, 6/30/20 00:00:00, 7/31/20 13:00:00]
months     = -3
output is [2/29/20 08:00:00, 3/30/20 00:00:00, 4/30/20 13:00:00]
 
timestamps = [4/28/20 04:00:00, 5/30/20 01:00:00, 6/30/20 21:00:00]
months     = 1
output is [5/28/20 04:00:00, 6/30/20 01:00:00, 7/30/20 21:00:00]

Exceptions

cudf::logic_error	if `timestamps` datatype is not a TIMESTAMP or if `months` datatype is not INT16 or INT32.
cudf::logic_error	if `timestamps` column size is not equal to `months` column size.

Parameters

timestamps	cudf::column_view of timestamp type
months	cudf::scalar of integer type containing the number of months to add
mr	Device memory resource used to allocate device memory of the returned column

Returns: cudf::column of timestamp type containing the computed timestamps

◆ ceil_datetimes()

std::unique_ptr<cudf::column> cudf::datetime::ceil_datetimes	(	cudf::column_view const &	column,
		rounding_frequency	freq,
		rmm::mr::device_memory_resource *	mr = `rmm::mr::get_current_device_resource()`
	)

Round datetimes up to the nearest multiple of the given frequency.

Parameters

column	cudf::column_view of the input datetime values
freq	rounding_frequency indicating the frequency to round up to
mr	Device memory resource used to allocate device memory of the returned column

Exceptions

cudf::logic_error if input column datatype is not TIMESTAMP.

Returns: cudf::column of the same datetime resolution as the input column

◆ day_of_year()

std::unique_ptr<cudf::column> cudf::datetime::day_of_year	(	cudf::column_view const &	column,
		rmm::mr::device_memory_resource *	mr = `rmm::mr::get_current_device_resource()`
	)

Computes the day number since the start of the year from the datetime and returns an int16_t cudf::column. The value is between [1, {365-366}].

Parameters

column	cudf::column_view of the input datetime values
mr	Device memory resource used to allocate device memory of the returned column

Returns: cudf::column of datatype INT16 containing the day number since the start of the year

Exceptions

cudf::logic_error if input column datatype is not a TIMESTAMP

◆ days_in_month()

std::unique_ptr<cudf::column> cudf::datetime::days_in_month	(	cudf::column_view const &	column,
		rmm::mr::device_memory_resource *	mr = `rmm::mr::get_current_device_resource()`
	)

Extract the number of days in the month.

output[i] contains the number of days in the month of date column[i] output[i] is null if column[i] is null

Exceptions

cudf::logic_error if input column datatype is not a TIMESTAMP

Parameters

column	cudf::column_view of the input datetime values
mr	Device memory resource used to allocate device memory of the returned column

Returns: cudf::column of datatype INT16 of days in month of the corresponding date

◆ extract_quarter()

std::unique_ptr<cudf::column> cudf::datetime::extract_quarter	(	cudf::column_view const &	column,
		rmm::mr::device_memory_resource *	mr = `rmm::mr::get_current_device_resource()`
	)

Returns the quarter of the date.

output[i] will be a value from {1, 2, 3, 4} corresponding to the quarter of month given by column[i]. It will be null if the input row at column[i] is null.

Exceptions

cudf::logic_error if input column datatype is not a TIMESTAMP

Parameters

column	The input column containing datetime values
mr	Device memory resource used to allocate device memory of the returned column

Returns: A column of INT16 type indicating which quarter the date is in

◆ floor_datetimes()

std::unique_ptr<cudf::column> cudf::datetime::floor_datetimes	(	cudf::column_view const &	column,
		rounding_frequency	freq,
		rmm::mr::device_memory_resource *	mr = `rmm::mr::get_current_device_resource()`
	)

Round datetimes down to the nearest multiple of the given frequency.

Parameters

column	cudf::column_view of the input datetime values
freq	rounding_frequency indicating the frequency to round down to
mr	Device memory resource used to allocate device memory of the returned column

Exceptions

cudf::logic_error if input column datatype is not TIMESTAMP.

Returns: cudf::column of the same datetime resolution as the input column

◆ is_leap_year()

std::unique_ptr<cudf::column> cudf::datetime::is_leap_year	(	cudf::column_view const &	column,
		rmm::mr::device_memory_resource *	mr = `rmm::mr::get_current_device_resource()`
	)

Check if the year of the given date is a leap year.

output[i] == true if year of column[i] is a leap year output[i] == false if year of column[i] is not a leap year output[i] is null if column[i] is null

Parameters

column	cudf::column_view of the input datetime values
mr	Device memory resource used to allocate device memory of the returned column

Returns: cudf::column of datatype BOOL8 truth value of the corresponding date

Exceptions

cudf::logic_error if input column datatype is not a TIMESTAMP

◆ last_day_of_month()

std::unique_ptr<cudf::column> cudf::datetime::last_day_of_month	(	cudf::column_view const &	column,
		rmm::mr::device_memory_resource *	mr = `rmm::mr::get_current_device_resource()`
	)

Computes the last day of the month in datetime type and returns a TIMESTAMP_DAYS cudf::column.

Parameters

column	cudf::column_view of the input datetime values
mr	Device memory resource used to allocate device memory of the returned column

Returns: cudf::column containing last day of the month as TIMESTAMP_DAYS

Exceptions

cudf::logic_error if input column datatype is not TIMESTAMP

◆ round_datetimes()

std::unique_ptr<cudf::column> cudf::datetime::round_datetimes	(	cudf::column_view const &	column,
		rounding_frequency	freq,
		rmm::mr::device_memory_resource *	mr = `rmm::mr::get_current_device_resource()`
	)

Round datetimes to the nearest multiple of the given frequency.

Parameters

column	cudf::column_view of the input datetime values
freq	rounding_frequency indicating the frequency to round to
mr	Device memory resource used to allocate device memory of the returned column

Exceptions

cudf::logic_error if input column datatype is not TIMESTAMP.

Returns: cudf::column of the same datetime resolution as the input column

Files

Enumerations

Functions

Detailed Description

Function Documentation

◆ add_calendrical_months() [1/2]

◆ add_calendrical_months() [2/2]

◆ ceil_datetimes()

◆ day_of_year()

◆ days_in_month()

◆ extract_quarter()

◆ floor_datetimes()

◆ is_leap_year()

◆ last_day_of_month()

◆ round_datetimes()