From 3ec8695b5d88a7ab55cfec254b066b94a9a48bd2 Mon Sep 17 00:00:00 2001
From: Collin Schwantes <schwantes@ecohealthalliance.org>
Date: Wed, 31 Jul 2024 10:57:31 -0600
Subject: [PATCH 1/6] adding function to obfuscate gps points

---
 R/obfuscate_gps.R | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 R/obfuscate_gps.R

diff --git a/R/obfuscate_gps.R b/R/obfuscate_gps.R
new file mode 100644
index 0000000..4d6b928
--- /dev/null
+++ b/R/obfuscate_gps.R
@@ -0,0 +1,34 @@
+#' Obfuscate GPS
+#'
+#' This function fuzzes gps points (or any other numeric values) by first adding
+#' error then rounding to a certain number of digits.
+#'
+#' @param x Numeric. Vector of gps points
+#' @param precision Integer. Number of digits to keep. See `round` for more details
+#' @param fuzz Numeric. Error to introduce to the gps measurements. This is used
+#' to generate the random uniform distribution `runif(1,min = -fuzz, max = fuzz)`
+#'
+#' @return Numeric. A vector of fuzzed and rounded GPS points
+#' @export
+#'
+#' @examples
+#'
+#' gps_data  <- data.frame(lat = c(1.0001, 10.22223, 4.00588), lon = c(2.39595, 4.506930, -60.09999901))
+#'
+#' gps_data |>
+#'   # default obfuscation settings correspont to roughly a 27 by 27 km area
+#'   dplyr::mutate(fuzzed_lat = obfuscate_gps(lat) %>%
+#'   # can be made more or less precise by changing the number of decimal points
+#'   # included or modifying the amount of fuzz (error) introduced
+#'   dplyr::mutate(fuzzed_lon = obfuscate_gps(lon, precision = 4, fuzz = 0.002))
+#'
+obfuscate_gps <- function(x, precision = 2, fuzz = 0.125){
+
+  # fuzz point
+  gps_error <- runif(1,min = -fuzz, max = fuzz)
+  x_fuzz <- x + gps_error
+
+  # round to 2 decimal points
+  out <- round(x_fuzz,digits = precision)
+  return(out)
+}

From f2104f12a2f69d67401e5a8b6c25cf0b5027ae2b Mon Sep 17 00:00:00 2001
From: Collin Schwantes <schwantes@ecohealthalliance.org>
Date: Wed, 31 Jul 2024 10:58:37 -0600
Subject: [PATCH 2/6] Increment version number to 0.3.0

---
 DESCRIPTION | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/DESCRIPTION b/DESCRIPTION
index d6345a9..cec59e3 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: ohcleandat
 Type: Package
 Title: One Health Data Cleaning and Quality Checking Package
-Version: 0.2.6
+Version: 0.3.0
 Authors@R: c(
     person("Collin", "Schwantes", email = "schwantes@ecohealthalliance.org", role = c("cre", "aut"), comment = c(ORCID = "0000-0003-4014-4896")),
     person("Johana", "Teigen", email = "teigen@ecohealthalliance.org", role = "aut", comment = c(ORCID = "0000-0002-6209-2321")),

From e570c1fea4d12d53d726a6953e01e9dc0b424516 Mon Sep 17 00:00:00 2001
From: Collin Schwantes <schwantes@ecohealthalliance.org>
Date: Wed, 31 Jul 2024 11:00:19 -0600
Subject: [PATCH 3/6] Add NEWS.md

---
 NEWS.md | 3 +++
 1 file changed, 3 insertions(+)
 create mode 100644 NEWS.md

diff --git a/NEWS.md b/NEWS.md
new file mode 100644
index 0000000..34ede4c
--- /dev/null
+++ b/NEWS.md
@@ -0,0 +1,3 @@
+# ohcleandat 0.3.0
+
+* Adding GPS obfuscation function

From afb62d74a167390289bfec2ec5af50287dd6ede2 Mon Sep 17 00:00:00 2001
From: Collin Schwantes <schwantes@ecohealthalliance.org>
Date: Wed, 31 Jul 2024 11:21:48 -0600
Subject: [PATCH 4/6] updating documentation

---
 DESCRIPTION          |  2 +-
 NAMESPACE            |  1 +
 R/obfuscate_gps.R    |  5 +++--
 man/obfuscate_gps.Rd | 36 ++++++++++++++++++++++++++++++++++++
 4 files changed, 41 insertions(+), 3 deletions(-)
 create mode 100644 man/obfuscate_gps.Rd

diff --git a/DESCRIPTION b/DESCRIPTION
index cec59e3..335bb16 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -14,7 +14,7 @@ Description: This package provides useful functions to orchestrate analytics and
 License: MIT + file LICENSE
 Encoding: UTF-8
 LazyData: true
-RoxygenNote: 7.3.2
+RoxygenNote: 7.3.2.9000
 Suggests: 
     knitr,
     rmarkdown
diff --git a/NAMESPACE b/NAMESPACE
index bfb3aa0..8434ec3 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -20,6 +20,7 @@ export(get_species_letter)
 export(guess_col_type)
 export(id_checker)
 export(make_report_urls)
+export(obfuscate_gps)
 export(othertext_lookup)
 export(read_excel_all_sheets)
 export(read_googlesheets)
diff --git a/R/obfuscate_gps.R b/R/obfuscate_gps.R
index 4d6b928..a21987c 100644
--- a/R/obfuscate_gps.R
+++ b/R/obfuscate_gps.R
@@ -13,7 +13,8 @@
 #'
 #' @examples
 #'
-#' gps_data  <- data.frame(lat = c(1.0001, 10.22223, 4.00588), lon = c(2.39595, 4.506930, -60.09999901))
+#' gps_data  <- data.frame(lat = c(1.0001, 10.22223, 4.00588),
+#'   lon = c(2.39595, 4.506930, -60.09999901))
 #'
 #' gps_data |>
 #'   # default obfuscation settings correspont to roughly a 27 by 27 km area
@@ -25,7 +26,7 @@
 obfuscate_gps <- function(x, precision = 2, fuzz = 0.125){
 
   # fuzz point
-  gps_error <- runif(1,min = -fuzz, max = fuzz)
+  gps_error <- stats::runif(1,min = -fuzz, max = fuzz)
   x_fuzz <- x + gps_error
 
   # round to 2 decimal points
diff --git a/man/obfuscate_gps.Rd b/man/obfuscate_gps.Rd
new file mode 100644
index 0000000..fee01a7
--- /dev/null
+++ b/man/obfuscate_gps.Rd
@@ -0,0 +1,36 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/obfuscate_gps.R
+\name{obfuscate_gps}
+\alias{obfuscate_gps}
+\title{Obfuscate GPS}
+\usage{
+obfuscate_gps(x, precision = 2, fuzz = 0.125)
+}
+\arguments{
+\item{x}{Numeric. Vector of gps points}
+
+\item{precision}{Integer. Number of digits to keep. See \code{round} for more details}
+
+\item{fuzz}{Numeric. Error to introduce to the gps measurements. This is used
+to generate the random uniform distribution \code{runif(1,min = -fuzz, max = fuzz)}}
+}
+\value{
+Numeric. A vector of fuzzed and rounded GPS points
+}
+\description{
+This function fuzzes gps points (or any other numeric values) by first adding
+error then rounding to a certain number of digits.
+}
+\examples{
+
+gps_data  <- data.frame(lat = c(1.0001, 10.22223, 4.00588),
+  lon = c(2.39595, 4.506930, -60.09999901))
+
+gps_data |>
+  # default obfuscation settings correspont to roughly a 27 by 27 km area
+  dplyr::mutate(fuzzed_lat = obfuscate_gps(lat) \%>\%
+  # can be made more or less precise by changing the number of decimal points
+  # included or modifying the amount of fuzz (error) introduced
+  dplyr::mutate(fuzzed_lon = obfuscate_gps(lon, precision = 4, fuzz = 0.002))
+
+}

From fb3d79772b8491689949390efa70369a3067fe2d Mon Sep 17 00:00:00 2001
From: Collin Schwantes <schwantes@ecohealthalliance.org>
Date: Wed, 31 Jul 2024 11:36:49 -0600
Subject: [PATCH 5/6] converted examples to base r

---
 R/obfuscate_gps.R    | 21 ++++++++++++---------
 man/obfuscate_gps.Rd | 19 +++++++++++--------
 2 files changed, 23 insertions(+), 17 deletions(-)

diff --git a/R/obfuscate_gps.R b/R/obfuscate_gps.R
index a21987c..7d453d9 100644
--- a/R/obfuscate_gps.R
+++ b/R/obfuscate_gps.R
@@ -13,15 +13,18 @@
 #'
 #' @examples
 #'
-#' gps_data  <- data.frame(lat = c(1.0001, 10.22223, 4.00588),
-#'   lon = c(2.39595, 4.506930, -60.09999901))
-#'
-#' gps_data |>
-#'   # default obfuscation settings correspont to roughly a 27 by 27 km area
-#'   dplyr::mutate(fuzzed_lat = obfuscate_gps(lat) %>%
-#'   # can be made more or less precise by changing the number of decimal points
-#'   # included or modifying the amount of fuzz (error) introduced
-#'   dplyr::mutate(fuzzed_lon = obfuscate_gps(lon, precision = 4, fuzz = 0.002))
+#'   gps_data  <- data.frame(lat = c(1.0001, 10.22223, 4.00588),
+#'     lon = c(2.39595, 4.506930, -60.09999901))
+#'
+#'   # Default obfuscation settings correspont to roughly a 27 by 27 km area
+#'   gps_data$lat |>
+#'    obfuscate_gps()
+#'
+#'   # Obfuscation can be made more or less precise by changing the number of
+#'   # decimal points included or modifying the amount of fuzz (error)
+#'   # introduced
+#'   gps_data$lon |>
+#'     obfuscate_gps(precision = 4, fuzz = 0.002)
 #'
 obfuscate_gps <- function(x, precision = 2, fuzz = 0.125){
 
diff --git a/man/obfuscate_gps.Rd b/man/obfuscate_gps.Rd
index fee01a7..61903c2 100644
--- a/man/obfuscate_gps.Rd
+++ b/man/obfuscate_gps.Rd
@@ -23,14 +23,17 @@ error then rounding to a certain number of digits.
 }
 \examples{
 
-gps_data  <- data.frame(lat = c(1.0001, 10.22223, 4.00588),
-  lon = c(2.39595, 4.506930, -60.09999901))
+  gps_data  <- data.frame(lat = c(1.0001, 10.22223, 4.00588),
+    lon = c(2.39595, 4.506930, -60.09999901))
 
-gps_data |>
-  # default obfuscation settings correspont to roughly a 27 by 27 km area
-  dplyr::mutate(fuzzed_lat = obfuscate_gps(lat) \%>\%
-  # can be made more or less precise by changing the number of decimal points
-  # included or modifying the amount of fuzz (error) introduced
-  dplyr::mutate(fuzzed_lon = obfuscate_gps(lon, precision = 4, fuzz = 0.002))
+  # Default obfuscation settings correspont to roughly a 27 by 27 km area
+  gps_data$lat |>
+   obfuscate_gps()
+
+  # Obfuscation can be made more or less precise by changing the number of
+  # decimal points included or modifying the amount of fuzz (error)
+  # introduced
+  gps_data$lon |>
+    obfuscate_gps(precision = 4, fuzz = 0.002)
 
 }

From 9dfe2c9af1904f08aa6620143ab043528395a9c7 Mon Sep 17 00:00:00 2001
From: Collin Schwantes <schwantes@ecohealthalliance.org>
Date: Thu, 1 Aug 2024 16:14:07 -0600
Subject: [PATCH 6/6] making obfuscate_gps more robust

---
 NAMESPACE            |   3 +
 NEWS.md              |   5 +-
 R/obfuscate_gps.R    | 194 +++++++++++++++++++++++++++++++++++++++----
 man/get_precision.Rd |  30 +++++++
 man/obfuscate_gps.Rd |  71 ++++++++++++----
 5 files changed, 272 insertions(+), 31 deletions(-)
 create mode 100644 man/get_precision.Rd

diff --git a/NAMESPACE b/NAMESPACE
index 8434ec3..a3a77b6 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -16,11 +16,14 @@ export(dropbox_upload)
 export(get_dropbox_val_logs)
 export(get_odk_form_schema)
 export(get_odk_responses)
+export(get_precision)
 export(get_species_letter)
 export(guess_col_type)
 export(id_checker)
 export(make_report_urls)
 export(obfuscate_gps)
+export(obfuscate_lat)
+export(obfuscate_lon)
 export(othertext_lookup)
 export(read_excel_all_sheets)
 export(read_googlesheets)
diff --git a/NEWS.md b/NEWS.md
index 34ede4c..e14876f 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,3 +1,6 @@
 # ohcleandat 0.3.0
 
-* Adding GPS obfuscation function
+* Adding GPS obfuscation function - this function uses two methods to reduce the
+accuracy of GPS points. The first is adding some amount of error to the measurement
+from a user defined random uniform distribution. The second is by rounding to
+remove precision from the measurement. 
diff --git a/R/obfuscate_gps.R b/R/obfuscate_gps.R
index 7d453d9..f1f5bbe 100644
--- a/R/obfuscate_gps.R
+++ b/R/obfuscate_gps.R
@@ -1,32 +1,99 @@
 #' Obfuscate GPS
 #'
-#' This function fuzzes gps points (or any other numeric values) by first adding
+#' This function fuzzes gps points by first adding
 #' error then rounding to a certain number of digits.
 #'
+#'
 #' @param x Numeric. Vector of gps points
-#' @param precision Integer. Number of digits to keep. See `round` for more details
-#' @param fuzz Numeric. Error to introduce to the gps measurements. This is used
-#' to generate the random uniform distribution `runif(1,min = -fuzz, max = fuzz)`
+#' @param precision Integer. Number of digits to keep. See `round` for more
+#' details
+#' @param fuzz Numeric. Positive number indicating how much error to introduce
+#' to the gps measurements. This is used to generate the random uniform
+#' distribution `runif(1,min = -fuzz, max = fuzz)`
+#' @param type Character. One of "lat" or "lon"
 #'
 #' @return Numeric. A vector of fuzzed and rounded GPS points
 #' @export
 #'
 #' @examples
 #'
-#'   gps_data  <- data.frame(lat = c(1.0001, 10.22223, 4.00588),
-#'     lon = c(2.39595, 4.506930, -60.09999901))
+#' # make data
+#' gps_data  <- data.frame(lat = c(1.0001, 10.22223, 4.00588),
+#'                         lon = c(2.39595, 4.506930, -60.09999901))
+#'
+#' # Default obfuscation settings correspont to roughly a 27 by 27 km area
+#' gps_data$lat |>
+#'   obfuscate_gps(type = "lat")
+#'
+#' # Obfuscation can be made more or less precise by changing the number of
+#' # decimal points included or modifying the amount of fuzz (error)
+#' # introduced
+#' gps_data$lon |>
+#'   obfuscate_gps(precision = 4, fuzz = 0.002, type = "lon")
+#'
+#' ### working at the poles
+#' gps_data_poles  <- data.frame(lat = c(89.0001, 89.22223, -89.8881),
+#'                               lon = c(2.39595, 4.506930, -60.09999901))
+#'
+#'
+#' gps_data_poles$lat |>
+#'   obfuscate_gps(fuzz = 1, type = "lat")
+#'
+#'
+#' ### working at the 180th meridian
+#' gps_data_180  <- data.frame(lat = c(2, 3, 4),
+#'                             lon = c(179.39595, -179.506930, -178.09999901))
+#' gps_data_180$lon |>
+#'   obfuscate_gps(fuzz = 1, type = "lon")
 #'
-#'   # Default obfuscation settings correspont to roughly a 27 by 27 km area
-#'   gps_data$lat |>
-#'    obfuscate_gps()
+#' ### GPS is on the fritz!
+#' \dontrun{
+#' gps_data_fritz <- data.frame(lat = c(91, -91, 90),
+#'                              lon = c(181.0001, -181.9877, -178.09999901))
+#' gps_data_fritz$lon |>
+#'   obfuscate_gps(fuzz = 1, type = "lon")
 #'
-#'   # Obfuscation can be made more or less precise by changing the number of
-#'   # decimal points included or modifying the amount of fuzz (error)
-#'   # introduced
-#'   gps_data$lon |>
-#'     obfuscate_gps(precision = 4, fuzz = 0.002)
+#' gps_data_fritz$lat |>
+#'   obfuscate_gps(fuzz = 1, type = "lat")
+#' }
 #'
-obfuscate_gps <- function(x, precision = 2, fuzz = 0.125){
+obfuscate_gps <- function(x, precision = 2, fuzz = 0.125, type = c("lat","lon")){
+
+  ## max precision in your data
+  # find value in x with most decimal points
+  data_precision <- get_precision(x,func = min)
+
+  msg_data_precision <- sprintf("The data have a max precision of: %s",data_precision)
+  message(msg_data_precision)
+
+  ## warning for max shift is fuzz+1e-precision
+  max_shift <- fuzz+10^-(precision/2)
+  msg_max_shift <- sprintf("The max shift from the combination of precision and fuzz is: %s degrees",max_shift)
+  message(msg_max_shift)
+
+  if(max_shift/fuzz > 2){
+    message("The majority of the obfuscation is coming from rounding, this
+    potentially makes re-identification easier")
+  }
+
+  ## check if obfuscation will have an impact on the data
+
+
+
+  type <- match.arg(type, c("lat","lon"))
+
+  if(type == "lat"){
+    out <- obfuscate_lat(x,precision,fuzz)
+  }
+
+  if(type == "lon"){
+    out <- obfuscate_lon(x,precision,fuzz)
+  }
+
+  return(out)
+}
+
+obfuscate_point <- function(x, precision = 2, fuzz = 0.125){
 
   # fuzz point
   gps_error <- stats::runif(1,min = -fuzz, max = fuzz)
@@ -36,3 +103,100 @@ obfuscate_gps <- function(x, precision = 2, fuzz = 0.125){
   out <- round(x_fuzz,digits = precision)
   return(out)
 }
+
+
+#' Obfuscates latitude data
+#'
+#' @rdname obfuscate_gps
+#'
+#' @return Numeric vector
+#' @export
+#'
+obfuscate_lat <- function(x, precision = 2, fuzz = 0.125){
+
+  ## check that fuzz doesnt exceed maximum values
+  if(fuzz > 90){
+    stop("fuzz greater than range of latitude on earth")
+  }
+
+  if(any(x > 90 | x < -90)){
+    stop("Latitude is outside the range of latitude on earth")
+  }
+
+  points <- obfuscate_point(x,precision,fuzz)
+
+  # make sure point is between 90 and -90
+  points_in_range <- purrr::map_dbl(points,function(point){
+    while(all(point > 90 | point < -90)){
+      point <- obfuscate_point(point,precision,fuzz)
+    }
+    return(point)
+  })
+
+  return(points_in_range)
+}
+
+
+#' Obfuscates longitude data
+#'
+#' @rdname obfuscate_gps
+#'
+#' @return Numeric vector
+#' @export
+#'
+obfuscate_lon <- function(x, precision = 2, fuzz = 0.125){
+
+  ## check that fuzz doesnt exceed maximum values
+  if(fuzz > 180){
+    stop("fuzz greater than range of longitude on earth")
+  }
+
+  if(any(x > 180 | x < -180)){
+    stop("Longitude is outside the range of longitude on earth ")
+  }
+
+  points <- obfuscate_point(x,precision,fuzz)
+
+  ### wrap points near the 180th meridian
+  points_in_range <- purrr::map_dbl(points,function(point){
+
+    # if point greater than 180, wrap
+     if(point > 180){
+      difference <- point - 180
+      point <- -180 + difference
+     }
+
+    # if point less than -180, wrap
+    if(point < -180){
+      difference <- -180-point
+      point <- 180 - difference
+    }
+
+    return(point)
+  })
+
+  return(points_in_range)
+}
+
+#' Get Precision
+#'
+#' @param x Numeric. Vector of gps points
+#' @param func Function. Apply some function to the vector of precisions. Default is c so that
+#' all values are returned
+#'
+#' @return output of func - likely a vector
+#' @export
+#' @author Nathan Layman
+#'
+#' @examples
+#'
+#' x <- c(1,100,1.11)
+#' get_precision(x,func = min)
+#'
+#'
+get_precision <- function(x,func = c) {
+  # number of characters with the decimal - number of chacters without it
+  precision <- 10^-(nchar(gsub("\\.", "", as.character(x))) - nchar(as.character(trunc(x))))
+   out <- func(precision)
+   return(out)
+}
diff --git a/man/get_precision.Rd b/man/get_precision.Rd
new file mode 100644
index 0000000..51e356c
--- /dev/null
+++ b/man/get_precision.Rd
@@ -0,0 +1,30 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/obfuscate_gps.R
+\name{get_precision}
+\alias{get_precision}
+\title{Get Precision}
+\usage{
+get_precision(x, func = c)
+}
+\arguments{
+\item{x}{Numeric. Vector of gps points}
+
+\item{func}{Function. Apply some function to the vector of precisions. Default is c so that
+all values are returned}
+}
+\value{
+output of func - likely a vector
+}
+\description{
+Get Precision
+}
+\examples{
+
+x <- c(1,100,1.11)
+get_precision(x,func = min)
+
+
+}
+\author{
+Nathan Layman
+}
diff --git a/man/obfuscate_gps.Rd b/man/obfuscate_gps.Rd
index 61903c2..c69e348 100644
--- a/man/obfuscate_gps.Rd
+++ b/man/obfuscate_gps.Rd
@@ -2,38 +2,79 @@
 % Please edit documentation in R/obfuscate_gps.R
 \name{obfuscate_gps}
 \alias{obfuscate_gps}
+\alias{obfuscate_lat}
+\alias{obfuscate_lon}
 \title{Obfuscate GPS}
 \usage{
-obfuscate_gps(x, precision = 2, fuzz = 0.125)
+obfuscate_gps(x, precision = 2, fuzz = 0.125, type = c("lat", "lon"))
+
+obfuscate_lat(x, precision = 2, fuzz = 0.125)
+
+obfuscate_lon(x, precision = 2, fuzz = 0.125)
 }
 \arguments{
 \item{x}{Numeric. Vector of gps points}
 
-\item{precision}{Integer. Number of digits to keep. See \code{round} for more details}
+\item{precision}{Integer. Number of digits to keep. See \code{round} for more
+details}
 
-\item{fuzz}{Numeric. Error to introduce to the gps measurements. This is used
-to generate the random uniform distribution \code{runif(1,min = -fuzz, max = fuzz)}}
+\item{fuzz}{Numeric. Positive number indicating how much error to introduce
+to the gps measurements. This is used to generate the random uniform
+distribution \code{runif(1,min = -fuzz, max = fuzz)}}
+
+\item{type}{Character. One of "lat" or "lon"}
 }
 \value{
 Numeric. A vector of fuzzed and rounded GPS points
+
+Numeric vector
+
+Numeric vector
 }
 \description{
-This function fuzzes gps points (or any other numeric values) by first adding
+This function fuzzes gps points by first adding
 error then rounding to a certain number of digits.
 }
 \examples{
 
-  gps_data  <- data.frame(lat = c(1.0001, 10.22223, 4.00588),
-    lon = c(2.39595, 4.506930, -60.09999901))
+# make data
+gps_data  <- data.frame(lat = c(1.0001, 10.22223, 4.00588),
+                        lon = c(2.39595, 4.506930, -60.09999901))
+
+# Default obfuscation settings correspont to roughly a 27 by 27 km area
+gps_data$lat |>
+  obfuscate_gps(type = "lat")
+
+# Obfuscation can be made more or less precise by changing the number of
+# decimal points included or modifying the amount of fuzz (error)
+# introduced
+gps_data$lon |>
+  obfuscate_gps(precision = 4, fuzz = 0.002, type = "lon")
 
-  # Default obfuscation settings correspont to roughly a 27 by 27 km area
-  gps_data$lat |>
-   obfuscate_gps()
+### working at the poles
+gps_data_poles  <- data.frame(lat = c(89.0001, 89.22223, -89.8881),
+                              lon = c(2.39595, 4.506930, -60.09999901))
 
-  # Obfuscation can be made more or less precise by changing the number of
-  # decimal points included or modifying the amount of fuzz (error)
-  # introduced
-  gps_data$lon |>
-    obfuscate_gps(precision = 4, fuzz = 0.002)
+
+gps_data_poles$lat |>
+  obfuscate_gps(fuzz = 1, type = "lat")
+
+
+### working at the 180th meridian
+gps_data_180  <- data.frame(lat = c(2, 3, 4),
+                            lon = c(179.39595, -179.506930, -178.09999901))
+gps_data_180$lon |>
+  obfuscate_gps(fuzz = 1, type = "lon")
+
+### GPS is on the fritz!
+\dontrun{
+gps_data_fritz <- data.frame(lat = c(91, -91, 90),
+                             lon = c(181.0001, -181.9877, -178.09999901))
+gps_data_fritz$lon |>
+  obfuscate_gps(fuzz = 1, type = "lon")
+
+gps_data_fritz$lat |>
+  obfuscate_gps(fuzz = 1, type = "lat")
+}
 
 }