Files | Enumerations | Functions
Compute Day

Files

file  datetime.hpp
 DateTime column APIs.
 

Enumerations

enum  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::columncudf::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 date time type and returns a TIMESTAMP_DAYS cudf::column. More...
 
std::unique_ptr< cudf::columncudf::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::columncudf::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 date time type and returns a timestamp column that is of the same type as the input timestamps column. More...
 
std::unique_ptr< cudf::columncudf::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 date time type and returns a timestamp column that is of the same type as the input timestamps column. More...
 
std::unique_ptr< cudf::columncudf::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::columncudf::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::columncudf::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::columncudf::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::columncudf::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::columncudf::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 date time 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_errorif timestamps datatype is not a TIMESTAMP or if months datatype is not INT16 or INT32.
cudf::logic_errorif timestamps column size is not equal to months column size.
Parameters
timestampscudf::column_view of timestamp type
monthscudf::column_view of integer type containing the number of months to add
mrDevice 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 date time 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_errorif timestamps datatype is not a TIMESTAMP or if months datatype is not INT16 or INT32.
cudf::logic_errorif timestamps column size is not equal to months column size.
Parameters
timestampscudf::column_view of timestamp type
monthscudf::scalar of integer type containing the number of months to add
mrDevice 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
columncudf::column_view of the input datetime values
freqrounding_frequency indicating the frequency to round up to
mrDevice memory resource used to allocate device memory of the returned column
Exceptions
cudf::logic_errorif 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
columncudf::column_view of the input datetime values
mrDevice 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_errorif 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_errorif input column datatype is not a TIMESTAMP
Parameters
columncudf::column_view of the input datetime values
mrDevice 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_errorif input column datatype is not a TIMESTAMP
Parameters
columnThe input column containing datetime values
mrDevice 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
columncudf::column_view of the input datetime values
freqrounding_frequency indicating the frequency to round down to
mrDevice memory resource used to allocate device memory of the returned column
Exceptions
cudf::logic_errorif 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
columncudf::column_view of the input datetime values
mrDevice 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_errorif 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 date time type and returns a TIMESTAMP_DAYS cudf::column.

Parameters
columncudf::column_view of the input datetime values
mrDevice 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_errorif 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
columncudf::column_view of the input datetime values
freqrounding_frequency indicating the frequency to round to
mrDevice memory resource used to allocate device memory of the returned column
Exceptions
cudf::logic_errorif input column datatype is not TIMESTAMP.
Returns
cudf::column of the same datetime resolution as the input column