Merge pull request #52 from natverse/fix/suggset-morpho

Suggest Morpho instead of importing it

DESCRIPTION

@@ -27,14 +27,14 @@ Imports:
     digest,
     igraph,
     memoise,
-    rappdirs,
-    Morpho
+    rappdirs
 Suggests:
     spelling,
     git2r (>= 0.22.1),
     nabor,
     testthat (>= 2.1.0),
-    covr
+    covr,
+    Morpho
 Encoding: UTF-8
 RoxygenNote: 7.2.3
 BugReports: https://github.com/natverse/nat.templatebrains/issues

R/fit-xform.R

@@ -8,7 +8,7 @@
 #' @param refpts An optional set of points in the target (fixed) space matching
 #'   \code{samplepts}. You must either supply this or the \code{reg} argument.
 #' @param type A character string specifying the type of registration. See
-#'   \code{\link{computeTransform}} for details.
+#'   \code{Morpho::computeTransform} for details.
 #' @param scale a 2-vector indicating the amount to scale the sample and
 #'   reference points. You can supply one vector if this is the same. If the
 #'   transform expects points in microns and returns points in microns then you
@@ -17,12 +17,15 @@
 #' @param subsample A number of points to subsample from
 #'   \code{samplepts,refpts}. The default value of \code{FALSE} means use all
 #'   provided points to calculate the new transform.
-#' @param ... Additional arguments passed to \code{\link{computeTransform}}
+#' @param ... Additional arguments passed to \code{Morpho::computeTransform}
 #'
-#' @return A homogeneous affine matrix or a \code{nat::tpsreg} object
-#'   n.b. only in development nat (>= 1.10.1)
+#' @return A homogeneous affine matrix or a \code{nat::tpsreg} object n.b. only
+#'   in development nat (>= 1.10.1)
 #' @export
 #'
+#' @details NB this function relies on installation of the suggested package
+#'   Morpho.
+#'
 #' @examples
 #' \dontrun{
 #' library(nat.flybrains)
@@ -53,6 +56,7 @@ fit_xform <- function(reg, samplepts, refpts=NULL, type = c("affine","rigid", "s
     refpts=xform(samplepts, reg)
   type=match.arg(type)
   if(length(scale)==1) scale=rep(scale,2)
+  check_package_available("Morpho")
   xt=Morpho::computeTransform(refpts*scale[2], samplepts*scale[1], type=type, ...)
   if(type=='tps') {
     class(xt)=union('tpsreg', class(xt))

R/utils.R

@@ -0,0 +1,5 @@
+check_package_available <- function(pkg) {
+  if(!requireNamespace(pkg, quietly = TRUE)) {
+    stop("Please install suggested package: ", pkg)
+  }
+}