convert_summary_stats_to_params {epiparameter} | R Documentation |
Convert the summary statistics of a distribution to parameters
Description
Convert the summary statistics for a range of distributions to the distribution's parameters. Most summary statistics are calculated analytically given the parameters. An exception is the Weibull distribution which uses a root finding numerical method.
Usage
convert_summary_stats_to_params(x, ...)
## S3 method for class 'character'
convert_summary_stats_to_params(
x = c("lnorm", "gamma", "weibull", "nbinom", "geom"),
...
)
## S3 method for class 'epiparameter'
convert_summary_stats_to_params(x, ...)
Arguments
x |
An R object. |
... |
< |
Details
Summary statistics should be named accordingly (case-sensitive):
mean:
mean
median:
median
mode:
mode
variance:
var
standard deviation:
sd
coefficient of variation:
cv
skewness:
skewness
excess kurtosis:
ex_kurtosis
Note: Not all combinations of summary statistics can be converted into distribution parameters. In this case the function will error stating that the parameters cannot be calculated from the given input.
The distribution names and parameter names follow the style of
distributions in R, for example the lognormal distribution is lnorm
,
and its parameters are meanlog
and sdlog
.
Value
A list of either one or two elements (depending on how many parameters the distribution has).
See Also
convert_params_to_summary_stats()
Examples
# examples using characters
convert_summary_stats_to_params("lnorm", mean = 1, sd = 1)
convert_summary_stats_to_params("weibull", mean = 2, var = 2)
convert_summary_stats_to_params("geom", mean = 2)
# examples using <epiparameter>
epiparameter <- epiparameter_db(single_epiparameter = TRUE)
convert_summary_stats_to_params(epiparameter)
# example using <epiparameter> and specifying summary stats
epiparameter$summary_stats <- list()
convert_summary_stats_to_params(epiparameter, mean = 10, sd = 2)