I have 1 know value of x. and I too have 1 formula. y = 0.92x now I want to flip LHS to RHS expected output will be x = y/0.92 its for multiplication and division. It should handle all basic mathematical operations. Is there any package for this in R or any one have defined function in R
I don't think there is any way to accomplish what you want. Rewriting mathematical formulas while they are represented as R functions is not an easy thing to do. What you can do is use uniroot to solve functions. For example:
# function for reversing a function. y is your y value
# only possible x values in interval will be considered.
inverseFun = function(y, fun, interval = c(-1e2, 1e2), ...) {
f = function(.y, .fun, ...) y - fun(...)
uniroot(f, interval, .y = y, .fun = fun, ...)
}
# standard math functions
add = function(a, b) a + b
substract = function(a, b) a - b
multiply = function(a, b) a * b
divide = function(a, b) a / b
# test it works
inverseFun(y = 3, add, b = 1)
# 2
inverseFun(y = -10, substract, b = 1)
# -9
inverseFun(y = 30, multiply, b = 2)
# 15
inverseFun(y = 30, divide, b = 1.75)
# 52.5
The above is an example, inverseFun(y = 3, `+`, b = 1) also works although it might be less clear what is happening. A last remark is that uniroot tries to minimize a function which might be time consuming for complicated functions.