How do I pre-determine mutually exclusive comparisons?
Another option is to use the library validatetools
(disclaimer, I'm its author).
library(validatetools)
rules <- validator( r1 = x < 1, r2 = x > 2)
is_infeasible(rules)
# [1] TRUE
make_feasible(rules)
# Dropping rule(s): "r1"
# Object of class 'validator' with 1 elements:
# r2: x > 2
# Rules are evaluated using locally defined options
# create a set of rules that all must hold:
rules <- validator( x > 1, x < 2, x < 2.5)
is_infeasible(rules)
# [1] FALSE
remove_redundancy(rules)
# Object of class 'validator' with 2 elements:
# V1: x > 1
# V2: x < 2
rules <- validator( x >= 1, x < 1)
is_infeasible(rules)
# [1] TRUE
To compare among ranges, min of the range max(s) should always be greater than the max of the range min(s), showed as below:
library(dplyr)
library(stringr)
areTherePossibleValues <- function(s) {
str_split(s, pattern = " *& *", simplify = TRUE)[1, ] %>%
{lapply(c("max" = "<", "min" = ">"), function(x) str_subset(., pattern = x) %>% str_extract(., pattern = "[0-9]+"))} %>%
{as.numeric(min(.$max)) > as.numeric(max(.$min))}
}
Update: add inclusion comparison
The only difference is that min of the range max(s) can be equal to the max of the range min(s).
library(dplyr)
library(stringr)
areTherePossibleValues <- function(s) {
str_split(s, pattern = " *& *", simplify = TRUE)[1, ] %>%
{lapply(c("max" = "<", "min" = ">"), function(x) str_subset(., pattern = x) %>% str_remove(., pattern = paste0("^.*", x)))} %>%
{ifelse(sum(grepl(pattern = "=", unlist(.))),
as.numeric(min(str_remove(.$max, "="))) >= as.numeric(max(str_remove(.$min, "="))),
as.numeric(min(.$max)) > as.numeric(max(.$min)))}
}
areTherePossibleValues("x<1 & x>2")
areTherePossibleValues("x>1 & x<2")
areTherePossibleValues("x>=1 & x<1")