conf_int: Function to calculate confidence intervals

In jentjr/gwstats: Tools for plotting and analyzing environmental data

Function to calculate confidence intervals

Description

Function to calculate confidence intervals

Usage

conf_int(
  df,
  analysis_result = "analysis_result",
  distribution = "distribution",
  method = "mvue",
  ci_type = "two-sided",
  conf_level = 0.95
)

Arguments

df	df data frame of groundwater data in tidy format
analysis_result	the analysis result column
distribution	the distribution column
method	character string specifying the method of estimation. Possible values are "mvue" (minimum variance unbiased; the default), and "mle/mme" (maximum likelihood/method of moments).
ci_type	character string indicating what kind of confidence interval to compute. The possible values are ci_type="two-sided" (the default), ci_type="lower", and ci_type = "upper
conf_level	a scalar between 0 and 1 indicating the confidence level of the prediction interval. The default value is conf_level = 0.95

Examples

data("gw_data")
wells <- c("MW-1", "MW-2", "MW-3", "MW-4")
params <- c("Sulfate, total",
            "Arsenic, dissolved",
            "Boron, dissolved")

background <- lubridate::ymd(c("2007-12-20", "2012-01-01"), tz = "UTC")
# first group data by location, param, and background
# estimate percent less than and distribution
background_data <- gw_data %>%
 filter(location_id %in% wells, param_name %in% params,
         sample_date >= background[1] & sample_date <= background[2]) %>%
  group_by(location_id, param_name, default_unit) %>%
  percent_lt() %>%
  est_dist(., keep_data_object = TRUE) %>%
  arrange(location_id, param_name)

background_data %>%
conf_int(., ci_type = "lower", conf_level = 0.99)

jentjr/gwstats documentation built on Jan. 12, 2024, 9:40 p.m.