is_locf: Checks to see if a value in a vector is LOCF
In cmu-delphi/epiprocess: Tools for basic signal processing in epidemiology
is_locf R Documentation
Checks to see if a value in a vector is LOCF
Description
LOCF meaning last observation carried forward (to later
versions). Lags the vector by 1, then compares with itself. If is_key is
TRUE, only values that are exactly the same between the lagged and
original are considered LOCF. If is_key is FALSE and vec is a vector
of numbers (base::is.numeric), then approximate equality will be used,
checking whether the absolute difference between each pair of entries is
<= abs_tol; if vec is something else, then exact equality is used
instead.
Usage
is_locf(vec, abs_tol, is_key)
Details
We include epikey-time columns in LOCF comparisons as part of an optimization
to avoid slower grouped operations while still ensuring that the first
observation for each time series will not be marked as LOCF. We test these
key columns for exact equality to prevent chopping off consecutive
time_values during flat periods when abs_tol is high.
We use exact equality for non-is.numeric double/integer columns such as
dates, datetimes, difftimes, tsibble::yearmonths, etc., as these may be
used as part of re-indexing or grouping procedures, and we don't want to
change the number of groups for those operations when we remove LOCF data
during compactification.
cmu-delphi/epiprocess documentation built on Feb. 22, 2025, 9:26 a.m.
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| is_locf | R Documentation |
Checks to see if a value in a vector is LOCF
Description
LOCF meaning last observation carried forward (to later
versions). Lags the vector by 1, then compares with itself. If is_key is
TRUE, only values that are exactly the same between the lagged and
original are considered LOCF. If is_key is FALSE and vec is a vector
of numbers (base::is.numeric), then approximate equality will be used,
checking whether the absolute difference between each pair of entries is
<= abs_tol; if vec is something else, then exact equality is used
instead.
Usage
is_locf(vec, abs_tol, is_key)
Details
We include epikey-time columns in LOCF comparisons as part of an optimization
to avoid slower grouped operations while still ensuring that the first
observation for each time series will not be marked as LOCF. We test these
key columns for exact equality to prevent chopping off consecutive
time_values during flat periods when abs_tol is high.
We use exact equality for non-is.numeric double/integer columns such as
dates, datetimes, difftimes, tsibble::yearmonths, etc., as these may be
used as part of re-indexing or grouping procedures, and we don't want to
change the number of groups for those operations when we remove LOCF data
during compactification.
R Package Documentation
Browse R Packages
We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
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