In byu-transpolab/nemsr: Process NEMS Datasets in R

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nemsr

The goal of nemsr is to enable researchers to quickly calculate NEMS-S scores for individual grocery stores using a Qualtrics-based NEMS-S survey developed at BYU.

Installation

You can install the development version from GitHub with:

# install.packages("devtools")
devtools::install_github("byu-transpolab/nemsr")

Example

The NEMS-S data should come from a Qualtrics survey collected by a trained surveyor. Download the data from Qualtrics in the .sav format (for SPSS). Then you can read the data into R with the read_nemss function.

library(nemsr)

## basic example code
file <- system.file("extdata", "example_nems.sav", package = "nemsr")
(nemss <- read_nemss(file))

Once the data are in your R session, there are two basic things you might like to do with them: a NEMS-S score and a market basket score.

NEMS-S Score

The calculate_nems_score() function computes the NEMS scores related to the cost and availability of healthier options at each grocery store. Additionally, a few variables relevant to the size and type of the store are returned in a tibble.

calculate_nems_score(nemss)

There is also a detail argument to this function that returns data columns showing the detail of the price and availability calculations.

calculate_nems_score(nemss, detail = TRUE)

Market Basket

The calculate_market_basket() function computes the cost of a common market basket at that store using the pricing data available weighted according to the Thrifty Food Plan, 2021

(basket_score <- calculate_market_basket(nemss))

For details on this function, its methods, and return information, see ?calculate_market_basket()

byu-transpolab/nemsr documentation built on Feb. 10, 2023, 11:24 p.m.