From 7637f45fe1d9f2d18d3cfdd7362f000ce3c5edb6 Mon Sep 17 00:00:00 2001
From: Robin Lovelace <rob00x@gmail.com>
Date: Mon, 30 Aug 2021 23:35:33 +0100
Subject: [PATCH] Improve docs for sequential_dist(), see #32

---
 R/slopes.R               | 8 +++++++-
 man/elevation_extract.Rd | 8 +++++++-
 man/sequential_dist.Rd   | 8 +++++++-
 man/slope_matrix.Rd      | 8 +++++++-
 4 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/R/slopes.R b/R/slopes.R
index d13f5da..95e4d1c 100644
--- a/R/slopes.R
+++ b/R/slopes.R
@@ -69,7 +69,13 @@ slope_distance_weighted = function(d, elevations) {
 #' @param elevations Elevations in same units as x (assumed to be metres).
 #'   Default value: `m[, 3]`, meaning the 'z' coordinate in a matrix of
 #'   coordinates.
-#' @param m Matrix containing coordinates and elevations
+#' @param m Matrix containing coordinates and elevations.
+#'   The matrix should have three columns: x, y, and z. Typically
+#'   these correspond to location in the West-East, South-North, and vertical
+#'   elevation axes respectively.
+#'   In data with geographic coordinates, Z values are assumed to be in
+#'   metres. In data with projected coordinates, Z values are assumed to have
+#'   the same units as the X and Y coordinates.
 #' @inheritParams slope_vector
 #' @inheritParams sequential_dist
 #' @return A vector of slope gradients associated with each linear element
diff --git a/man/elevation_extract.Rd b/man/elevation_extract.Rd
index 87634d3..b847107 100644
--- a/man/elevation_extract.Rd
+++ b/man/elevation_extract.Rd
@@ -12,7 +12,13 @@ elevation_extract(
 )
 }
 \arguments{
-\item{m}{Matrix containing coordinates and elevations}
+\item{m}{Matrix containing coordinates and elevations.
+The matrix should have three columns: x, y, and z. Typically
+these correspond to location in the West-East, South-North, and vertical
+elevation axes respectively.
+In data with geographic coordinates, Z values are assumed to be in
+metres. In data with projected coordinates, Z values are assumed to have
+the same units as the X and Y coordinates.}
 
 \item{dem}{Raster overlapping with \code{routes} and values representing elevations}
 
diff --git a/man/sequential_dist.Rd b/man/sequential_dist.Rd
index 134ead3..465f151 100644
--- a/man/sequential_dist.Rd
+++ b/man/sequential_dist.Rd
@@ -7,7 +7,13 @@
 sequential_dist(m, lonlat = TRUE)
 }
 \arguments{
-\item{m}{Matrix containing coordinates and elevations}
+\item{m}{Matrix containing coordinates and elevations.
+The matrix should have three columns: x, y, and z. Typically
+these correspond to location in the West-East, South-North, and vertical
+elevation axes respectively.
+In data with geographic coordinates, Z values are assumed to be in
+metres. In data with projected coordinates, Z values are assumed to have
+the same units as the X and Y coordinates.}
 
 \item{lonlat}{Are the coordinates in lon/lat (geographic) coordinates? TRUE by default.}
 }
diff --git a/man/slope_matrix.Rd b/man/slope_matrix.Rd
index 49cca6e..5c5e0be 100644
--- a/man/slope_matrix.Rd
+++ b/man/slope_matrix.Rd
@@ -13,7 +13,13 @@ slope_matrix_mean(m, elevations = m[, 3], lonlat = TRUE)
 slope_matrix_weighted(m, elevations = m[, 3], lonlat = TRUE)
 }
 \arguments{
-\item{m}{Matrix containing coordinates and elevations}
+\item{m}{Matrix containing coordinates and elevations.
+The matrix should have three columns: x, y, and z. Typically
+these correspond to location in the West-East, South-North, and vertical
+elevation axes respectively.
+In data with geographic coordinates, Z values are assumed to be in
+metres. In data with projected coordinates, Z values are assumed to have
+the same units as the X and Y coordinates.}
 
 \item{elevations}{Elevations in same units as x (assumed to be metres).
 Default value: \code{m[, 3]}, meaning the 'z' coordinate in a matrix of