ts_index returns an indexed series, with value of 1 at the base date or range. ts_compound builds an index from percentage change rates, starting with 1 and compounding the rates.

ts_compound(x, denominator = 100)

ts_index(x, base = NULL)

Arguments

x

ts-boxable time series, an object of class ts, xts, zoo, data.frame, data.table, tbl, tbl_ts, tbl_time, tis, irts or timeSeries.

denominator

numeric, set equal to one if percentage change rate is given a decimal fraction

base

base date, character string, Date or POSIXct, at which the index is set to 1. If two dates are provided, the average with the range is set equal to 1 (see examples).

Value

a ts-boxable time series, with the same class as the input.

Examples

head(ts_compound(ts_pc(ts_c(fdeaths, mdeaths))))
#> fdeaths mdeaths #> Jan 1974 1.0000000 1.0000000 #> Feb 1974 0.7647059 0.8730084 #> Mar 1974 0.9178690 0.8795689 #> Apr 1974 0.7513873 0.8795689 #> May 1974 0.5793563 0.6991565 #> Jun 1974 0.4506104 0.5852858
head(ts_index(ts_df(ts_c(fdeaths, mdeaths)), "1974-02-01"))
#> id time value #> 1 fdeaths 1974-01-01 1.3076923 #> 2 fdeaths 1974-02-01 1.0000000 #> 3 fdeaths 1974-03-01 1.2002903 #> 4 fdeaths 1974-04-01 0.9825835 #> 5 fdeaths 1974-05-01 0.7576197 #> 6 fdeaths 1974-06-01 0.5892598
# \donttest{ ts_plot( `My Expert Knowledge` = ts_chain( mdeaths, ts_compound(ts_bind(ts_pc(mdeaths), 15, 23, 33))), `So Far` = mdeaths, title = "A Very Manual Forecast" )
# average of 1974 = 1 ts_index(mdeaths, c("1974-01-01", "1974-12-31"))
#> Jan Feb Mar Apr May Jun Jul #> 1974 1.3427717 1.1722511 1.1810602 1.1810602 0.9388076 0.7859053 0.8054114 #> 1975 1.3232657 1.3446594 1.3547271 1.1533742 0.8828064 0.8104452 0.7462640 #> 1976 1.2710398 1.7303760 1.4365267 0.9306277 0.7481516 0.7299040 0.7003303 #> 1977 1.4094699 1.0281579 1.0835300 1.1332389 0.7840176 0.7311625 0.6839704 #> 1978 1.2704106 1.4371559 1.2219600 0.8953909 0.8431650 0.7468932 0.6908919 #> 1979 1.4239421 1.1451943 1.1615542 0.9633475 0.7645116 0.6764197 0.6644644 #> Aug Sep Oct Nov Dec #> 1974 0.7116564 0.7607362 0.9388076 1.0199780 1.1615542 #> 1975 0.7129149 0.6625767 0.8475696 0.9721567 1.2999843 #> 1976 0.6103508 0.6285984 0.7601070 0.9230769 1.2955797 #> 1977 0.6374076 0.6034293 0.7418594 0.7733207 1.0413717 #> 1978 0.6317445 0.6103508 0.7173195 0.6984427 1.1401605 #> 1979 0.6134969 0.5914740 0.6801951 0.8142205 0.8437942
# }