acs_est_sum: Calculate the a derived sum of ACS variables
In austensen/acssf: Download ACS Summary File Data and Build Database

This function calculates a derived sum of ACS variables from the ACS estimates returned by acs_transform(). It assumes the data structure of a dataframe returned by acs_transform(), where each row is a geography and each column is an ACS estimate or margin of error, and so is used within a dplyr::mutate() call and sums across rows. The main argument to this function is first parsed with acs_vars() and then the columns are found within the dataframe.

1	acs_est_sum(..., na.rm = TRUE, .envir = parent.frame())

`na.rm`	[`logical: TRUE`]: A logical value indicating whether NA values should be stripped before the computation proceeds.
`.envir`	[`environment: parent.frame()`]: Environment to evaluate each expression in. Expressions are evaluated from left to right. If .x is an environment, the expressions are evaluated in that environment and .envir is ignored.
`...\['expressions']:`	Expressions string(s) to format into ACS variable estimate codes with `acs_vars()`.