Euclidean distance

.Rbuildignore

@@ -6,3 +6,4 @@
 ^docs$
 ^pkgdown$
 ^\.lintr$
+^data-raw$

.gitignore

@@ -39,4 +39,3 @@ vignettes/*.pdf
 # R Environment Variables
 .Renviron
 inst/doc
-docs

DESCRIPTION

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 Package: DevelExample
 Title: A Basic R Package to Demonstrate a Cycle of Code Development
-Version: 0.0.1
+Version: 0.1.0
 Authors@R: 
     person(given = "Joshua",
            family = "Campbell",
@@ -22,3 +22,5 @@ Suggests:
     testthat (>= 3.0.0)
 Config/testthat/edition: 3
 VignetteBuilder: knitr
+Depends: 
+    R (>= 2.10)

NAMESPACE

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 # Generated by roxygen2: do not edit by hand
 
+export(euclideanDist)
 export(hello)

NEWS.md

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+# Changes in Version 0.1.0 (2022-05-20)
+* Added function to calculate euclidean distance
+
 # Changes in Version 0.0.1 (2022-05-08)
 * Created package
 * Added Hello World function

R/data.R

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+#' Example dataset
+#'
+#' A dataset containing a matrix with two columns that were generated
+#' with a random normal distribution with a mean of 0 and stdev of 1.
+#'
+#' @format A matrix with 100 rows and 2 columns
+#' @keywords datasets
+#' @usage data("example_data")
+#' @examples
+#' data("example_data")
+"example_data"

R/distance.R

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+#' @title Euclidean distance
+#' @description Calculates Euclidean distance between two vectors. An error
+#' will be given if NAs are present in either vector.
+#'
+#' @param a The first vector to use in the distance calculation.
+#' @param b The second vector to use in the distance calculation.
+#' @param verbose Boolean. If \code{TRUE}, a message will be printed.
+#' Default \code{TRUE}.
+#' @return A numeric value of a distance
+#' @examples
+#' data(example_data)
+#' euclideanDist(example_data[,1], example_data[,2], verbose = FALSE)
+#' @export
+euclideanDist <- function(a, b, verbose = FALSE) {
+  if (isTRUE(verbose)) {
+    message("Calculating distance ...")
+  }
+
+  # Check validity of data
+  .checkData(a)
+  .checkData(b)
+
+  # Perform calculation
+  res <- sqrt(sum((a - b) ^ 2))
+  return(res)
+}
+
+#' Validity check
+#'
+#' This functions checks for NAs in a vector
+#'
+#' @param input A numeric vector
+#' @return Nothing returned
+.checkData <- function(input) {
+  if (any(is.na(input))) {
+    stop("'input' must not contain NAs")
+  }
+}

data-raw/example_data.R

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+## code to prepare `example_data` dataset goes here
+set.seed(123)
+a <- rnorm(100)
+b <- rnorm(100)
+example_data <- cbind(a, b)
+usethis::use_data(example_data, overwrite = TRUE)