Merge pull request #74 from venpopov/45-robust-check-response-variabl…

…e-for-CRT

Update data check and add deg2rad & rad2deg

NAMESPACE

@@ -25,6 +25,7 @@ export(calc_error_relative_to_nontargets)
 export(check_data)
 export(configure_model)
 export(dIMM)
+export(deg2rad)
 export(dmixture2p)
 export(dmixture3p)
 export(dsdm)
@@ -46,6 +47,7 @@ export(qmixture2p)
 export(qmixture3p)
 export(qsdm)
 export(rIMM)
+export(rad2deg)
 export(rmixture2p)
 export(rmixture3p)
 export(rsdm)

R/helpers-data.R

@@ -55,14 +55,12 @@ check_data.default <- function(model, data, formula) {
 #' @export
 check_data.vwm <- function(model, data, formula) {
   resp_name <- get_response(formula$formula)
-  if (max(abs(data[[resp_name]]), na.rm=T) > 10) {
-    data[[resp_name]] <- data[[resp_name]]*pi/180
-    warning('It appears your response variable is in degrees. We will transform it to radians.')
+  if (max(abs(data[[resp_name]]), na.rm = T) > 2*pi) {
+    warning('It appears your response variable is in degrees.\n
+             The model requires the response variable to be in radians.\n
+             The model will continue to run, but the results may be compromised.')
   }
 
-  # wrap recoded responses around the circle (range = -pi to pi)
-  data[[resp_name]] <- wrap(data[[resp_name]])
-
   data = NextMethod("check_data")
 
   return(data)
@@ -72,9 +70,10 @@ check_data.vwm <- function(model, data, formula) {
 #' @export
 check_data.nontargets <- function(model, data, formula) {
   non_targets <- model$vars$non_targets
-  if (max(abs(data[,non_targets]), na.rm=T) > 10) {
-    data[,non_targets] <- data[,non_targets]*pi/180
-    warning('It appears your non_target variables are in degrees. We will transform it to radians.')
+  if (max(abs(data[,non_targets]), na.rm = T) > 2*pi) {
+    warning('It appears at least one of your non_target variables are in degrees.\n
+             The model requires these variable to be in radians.\n
+            The model will continue to run, but the results may be compromised.')
   }
 
   setsize <- model$vars$setsize
@@ -98,9 +97,6 @@ check_data.nontargets <- function(model, data, formula) {
          '`non_targets` is more than max(setsize)-1')
   }
 
-  # wrap non_target variables around the circle (range = -pi to pi)
-  data[,non_targets] <- wrap(data[,non_targets])
-
   # create index variables for non_targets and correction variable for theta due to setsize
   lure_idx_vars <- paste0('LureIdx',1:(max_setsize - 1))
   for (i in 1:(max_setsize - 1)) {
@@ -180,3 +176,28 @@ wrap <- function(x, radians=TRUE) {
     return(((x+180) %% (2*180)) - 180)
   }
 }
+
+#' @title Convert degrees to radians or radians to degrees.
+#' @description
+#'   The helper functions `deg2rad` and `rad2deg` should add convenience in transforming
+#'   data from degrees to radians and from radians to degrees.
+#'
+#' @name circle_transform
+#' @param deg A numeric vector of values in degrees.
+#' @param rad A numeric vector of values in radians.
+#' @return A numeric vector of the same length as `deg` or `rad`.
+#' @keywords transform
+#' @export
+#' @examples
+#'   degrees <- runif(100, min = 0, max = 360)
+#'   radians <- deg2rad(degrees)
+#'   degrees_again <- rad2deg(radians)
+deg2rad <- function(deg){
+  deg * pi / 180
+}
+
+#' @rdname circle_transform
+#' @export
+rad2deg <- function(rad){
+  rad * 180 / pi
+}

tests/testthat/test-helpers-data.R

@@ -11,7 +11,7 @@ test_that("check_data() produces expected errors and warnings", {
     expect_warning(check_data(ml(non_targets = 'x', setsize=2, spaPos = 'z'),
                               data.frame(y = 12, x = 1, z = 2),
                               brms::bf(y ~ 1)),
-                   "It appears your response variable is in degrees. We will transform it to radians.")
+                   "It appears your response variable is in degrees.\n")
     expect_silent(check_data(ml(non_targets = 'x', setsize=2, spaPos = 'z'),
                              data.frame(y = 1, x = 1, z = 2), brms::bf(y ~ 1)))
   }
@@ -71,3 +71,14 @@ test_that("wrap(x) returns the correct value for values between (3*pi,4*pi)", {
   x <- 3*pi+1
   expect_equal(wrap(x), -(pi-1))
 })
+
+
+test_that("deg2rad returns the correct values for 0, 180, 360", {
+  x <- c(0,90,180)
+  expect_equal(round(deg2rad(x),2),c(0.00,1.57,3.14))
+})
+
+test_that("rad2deg returns the correct values for 0, pi/2, 2*pi", {
+  x <- c(0, pi/2, 2*pi)
+  expect_equal(round(rad2deg(x),2),c(0,90,360))
+})