Further improvements to persp.linim

Author: baddstats

DESCRIPTION

@@ -1,5 +1,5 @@
 Package: spatstat.linnet
-Version: 3.4-0.004
+Version: 3.4-0.006
 Date: 2025-12-12
 Title: Linear Networks Functionality of the 'spatstat' Family
 Authors@R: c(person("Adrian", "Baddeley", 

NEWS

@@ -1,5 +1,5 @@
 
-        CHANGES IN spatstat.linnet VERSION 3.4-0.004
+        CHANGES IN spatstat.linnet VERSION 3.4-0.006
 
 OVERVIEW
 
@@ -19,7 +19,10 @@ SIGNIFICANT USER-VISIBLE CHANGES
     o persp.linim
     Argument 'col.base' can be a pixel image, allowing a colour image
     to be plotted on the horizontal plane at height zero.
-    
+
+    o persp.linim
+    New argument 'zadjust' to control vertical scale.
+
         CHANGES IN spatstat.linnet VERSION 3.4-0
 
 OVERVIEW

R/perspex.R

@@ -18,6 +18,7 @@ persp.linim <- local({
   persp.linim <- function(x, ..., main, grid=TRUE, ngrid=10,
                           col.grid="grey", col.base="white",
                           neg.args=list(), warncross=FALSE,
+                          zadjust=1,
                           extrapolate=c("linear", "constant")) {
     xname <- short.deparse(substitute(x))
     if(missing(main)) main <- xname
@@ -26,6 +27,13 @@ persp.linim <- local({
     #' 
     L <- as.linnet(x)
     R <- Frame(L)
+    #' rescale function values to a scale commensurate with window
+    #'  (to achieve appropriate default scale in persp.default)
+    xmax <- max(abs(x))
+    if(rescaled <- (xmax > .Machine$double.eps)) {
+      scal <- max(sidelengths(R))/xmax
+      x    <- scal * x
+    }
     zlim <- range(x, 0)
     #' set up perspective transformation and plot horizontal plane
     if(is.im(col.base)) {
@@ -36,7 +44,7 @@ persp.linim <- local({
       BaseInfo <- list(colin=col.base)
     } else if(is.colour(col.base)) {
       #' Usual case: horizontal plane will be a single colour
-      Z <- as.im(0, W=R, dimyx=ngrid)
+      Z <- as.im(0, W=R, dimyx=rev(ngrid))
       #' Draw grid lines by setting 'border' argument of persp.default
       #' provided the function has no negative values
       border <- if(grid && (zlim[1] >= 0)) col.grid else NA
@@ -49,8 +57,10 @@ persp.linim <- local({
                              BaseInfo,
                              dotargs,
                              list(axes=FALSE, box=FALSE,
-                                  zlim=zlim, zlab=xname, 
-                                  scale=TRUE, expand=0.1))
+                                  zlim=zlim, zlab=xname,
+                                  scale=!rescaled,
+                                  #' expand=0.1 is default in persp.default
+                                  expand=zadjust * 0.1))
     M <- do.call.matched(persp.im, argh,
                          extrargs=graphicsPars("persp"))
     #' compute the projection of the linear network

inst/doc/packagesizes.txt

@@ -42,4 +42,4 @@ date version nhelpfiles nobjects ndatasets Rlines srclines
 "2025-07-24" "3.3-1" 150 328 0 13326 3270
 "2025-09-24" "3.3-2" 150 328 0 13356 3270
 "2025-11-29" "3.4-0" 160 370 0 14990 3270
-"2025-12-12" "3.4-0.004" 160 371 0 15166 3270
+"2025-12-12" "3.4-0.006" 160 371 0 15176 3270

inst/info/packagesizes.txt

@@ -42,4 +42,4 @@ date version nhelpfiles nobjects ndatasets Rlines srclines
 "2025-07-24" "3.3-1" 150 328 0 13326 3270
 "2025-09-24" "3.3-2" 150 328 0 13356 3270
 "2025-11-29" "3.4-0" 160 370 0 14990 3270
-"2025-12-12" "3.4-0.004" 160 371 0 15166 3270
+"2025-12-12" "3.4-0.006" 160 371 0 15176 3270

man/persp.linim.Rd

@@ -11,6 +11,7 @@
                        grid = TRUE, ngrid = 10,
                        col.grid = "grey", col.base = "white",
                        neg.args=list(), warncross=FALSE,
+                       zadjust=1,
                        extrapolate=c("linear", "constant"))
 }
 \arguments{
@@ -50,6 +51,9 @@
     two segments of the network cross each other (which causes
     difficulty for the algorithm).
   }
+  \item{zadjust}{
+    Adjustment factor for vertical scale, relative to the default scale.
+  }
   \item{extrapolate}{
     Character string (partially matched) specifying how to extrapolate
     the value at the endpoint of each segment.
@@ -100,6 +104,14 @@
   other than white, or if \code{col.base} is a pixel image.
   A transparent colour for \code{col.base} can be used
   if it is supported by the graphics device.
+
+  Like all spatial plots in the \pkg{spatstat} family,
+  \code{persp.linim} does not independently rescale
+  the \eqn{x} and \eqn{y} coordinates. A long narrow window will be
+  represented as a long narrow window in the perspective view.
+  To override this and allow the coordinates to be independently
+  rescaled, use the argument \code{scale=TRUE} which will be passed
+  to \code{\link[graphics]{persp.default}}.
 }
 \value{
   (Invisibly) the perspective transformation matrix,