vlookup {psm3mkv} | R Documentation |
VLOOKUP function
Description
Function to lookup values according to an index. Aims to behave similarly to VLOOKUP in Microsoft Excel, however several lookups can be made at once (indexval
can be a vector) and interpolation is available where lookups are inexact (choice of 4 methods).
Usage
vlookup(indexval, indexvec, valvec, method = "geom")
Arguments
indexval |
The index value to be looked-up (may be a vector of multiple values) |
indexvec |
The vector of indices to look-up within |
valvec |
The vector of values corresponding to the vector of indices |
method |
Method may be |
Value
Numeric value or vector, depending on the lookup/interpolation method chosen:
-
floor
: Floor (minimum) value, where interpolation is required between measured values -
ceiling
: Ceiling (maximum) value, where interpolation is required between measured values -
arith
: Arithmetic mean, where interpolation is required between measured values -
geom
: Geometric mean, where interpolation is required between measured values
See Also
HMDHFDplus::readHMDweb can be used to obtain lifetables from the Human Mortality Database
Examples
# Suppose we have survival probabilities at times 0 to 20
times <- 0:20
survival <- 1-times*0.04
# We would like to look-up the survival probability at time 7
vlookup(7, times, survival)
# In this case, the floor, ceiling, arith and geom values are identical
# because survival time 7 is known, and no interpolation is necessary
vlookup(c(7, 7.5), times, survival)
# The second row of the returned tibble reveal different estimates of the survival at time 7.5.
# The values vary according to the interpolation method between
# observed survival values at times 7 and 8.