Dynmar log axes

NEWS.md

@@ -209,6 +209,11 @@ related to plot layering. See "Bug fixes" below.
 
 ### Bug fixes
 
+- Fixed a bug where consecutive plots with (i) logged axes under (ii) a dynamic
+  theme would error, due to a stale `par("xlog")`/`par("ylog")` state. We now
+  avoid this by grabbing the log state directly from the top-level `log`
+  argument instead. Thanks to @eddelbuettel for the report.
+  (#725 @grantmcdermott)
 - `type_barplot()` receives several consistency improvements and bug fixes:
   - Passing a named atomic vector now uses the names as the bar categories,
     matching base `barplot()`. (#714 @grantmcdermott)

R/facet.R

@@ -57,6 +57,13 @@ draw_facet_window = function(
   }
 
 
+  # Both dynmar branches below measure tick labels before the plot.window()
+  # calls in the facet loop, so the log state has to come from the caller's
+  # `log` argument -- par("xlog")/par("ylog") still describe the previous plot
+  # at that point (#725).
+  .xlog = grepl("x", log, fixed = TRUE)
+  .ylog = grepl("y", log, fixed = TRUE)
+
   # if breaks are provided use these (but only if x/ylabs are null)
   if (!is.null(xaxb) && !is.null(xlabs)) xlabs = xaxb
   if (!is.null(yaxb) && !is.null(ylabs)) ylabs = yaxb
@@ -196,7 +203,7 @@ draw_facet_window = function(
         }
         yaxlabs = axis_tick_labels(
           .ylabset,
-          lim = ylim, axb = yaxb, axl = yaxl, log = par("ylog"),
+          lim = ylim, axb = yaxb, axl = yaxl, log = .ylog,
           free_lims = .yfree, cex = .cex_yaxs
         )
         whtsbp = if (!is.null(yaxr)) {
@@ -229,7 +236,7 @@ draw_facet_window = function(
         }
         xaxlabs = axis_tick_labels(
           .xlabset,
-          lim = xlim, axb = xaxb, axl = xaxl, log = par("xlog"),
+          lim = xlim, axb = xaxb, axl = xaxl, log = .xlog,
           free_lims = .xfree, cex = .cex_xaxs
         )
         whtsbp = if (!is.null(xaxr)) {
@@ -309,7 +316,7 @@ draw_facet_window = function(
       # extra whitespace bump on the y axis
       yaxlabs = axis_tick_labels(
         y_axis_labels(type, y, ylabs, xlabs, flip),
-        lim = ylim, axb = yaxb, axl = yaxl, log = par("ylog"),
+        lim = ylim, axb = yaxb, axl = yaxl, log = .ylog,
         cex = .cex_yaxs
       )
       if (!is.null(yaxr)) {
@@ -323,7 +330,7 @@ draw_facet_window = function(
       # extra whitespace bump on the x axis
       xaxlabs = axis_tick_labels(
         x_axis_labels(xlabs),
-        lim = xlim, axb = xaxb, axl = xaxl, log = par("xlog"),
+        lim = xlim, axb = xaxb, axl = xaxl, log = .xlog,
         cex = .cex_xaxs
       )
       if (!is.null(xaxr)) {

R/tinyAxis.R

@@ -164,34 +164,59 @@ x_axis_labels = function(xlabs) {
 ## clear every panel's ticks, so all of them are measured and the widest wins.
 axis_tick_labels = function(labelset, lim, axb = NULL, axl = NULL, log = FALSE,
                             free_lims = NULL, cex = 1) {
+  ticks = function(l) {
+    u = axis_usr(l, log = log, axb = axb)
+    axisTicks(usr = u[["usr"]], log = u[["log"]])
+  }
   if (!is.null(labelset)) {
     out = labelset[[1L]]
   } else if (!is.null(free_lims)) {
-    sets = lapply(free_lims, function(l) {
-      axisTicks(usr = extendrange(l, f = 0.04), log = log)
-    })
+    sets = lapply(free_lims, ticks)
     widths = vapply(
       sets,
       function(s) max(strwidth(s, "inches", cex = cex)),
       numeric(1L)
     )
     out = sets[[which.max(widths)]]
   } else {
-    # A single distinct value gives a zero-width range that extendrange() can't
-    # pad and axisTicks() can't tick, so widen it the way plot.window() does.
-    # An explicit `at` (xaxb/yaxb) supplies its own ticks, hence the guard.
-    usr = if (diff(lim) == 0 && is.null(axb)) {
-      lim + c(-0.5, 0.5)
-    } else {
-      extendrange(lim, f = 0.04)
-    }
-    out = axisTicks(usr = usr, log = log)
+    out = ticks(lim)
   }
   if (!is.null(axl)) out = tinylabel(out, axl)
   out
 }
 
 
+## Axis limits in the coordinate space axisTicks() and par("usr") speak.
+##
+## Callers hold limits in *data* units, but on a log axis axisTicks() reads
+## its `usr` in log10 units. Keeping that conversion here -- rather than
+## leaving each call site to remember it -- is the point of this helper: the
+## units contract and the padding rules stay in one place. Returns the padded
+## limits together with the log flag they were built under, so the caller
+## hands axisTicks() a matching pair.
+##
+## Margin measurement runs *before* plot.window(), so `log` must come from the
+## caller's own `log=` argument. par("xlog")/par("ylog") still describe the
+## previous plot on the device at that point (#725).
+##
+## A log axis can't represent a zero or negative limit, so those fall back to a
+## linear measurement: plot.window() raises its own, clearer complaint moments
+## later, and log10() here would only put "NaNs produced" in front of it.
+axis_usr = function(lim, log = FALSE, axb = NULL) {
+  log = isTRUE(log) && all(is.finite(lim)) && all(lim > 0)
+  if (log) lim = log10(lim)
+  # A single distinct value gives a zero-width range that extendrange() can't
+  # pad and axisTicks() can't tick, so widen it the way plot.window() does.
+  # An explicit `at` (xaxb/yaxb) supplies its own ticks, hence the guard.
+  usr = if (diff(lim) == 0 && is.null(axb)) {
+    lim + c(-0.5, 0.5)
+  } else {
+    extendrange(lim, f = 0.04)
+  }
+  list(usr = usr, log = log)
+}
+
+
 ## Margin lines a side must reserve to clear its tick labels ("whtsbp").
 ##
 ## Under las 1:2 the y labels are horizontal and their *width* eats into mar[2];

R/tinyplot.R

@@ -1317,6 +1317,11 @@ tinyplot.default = function(
     .whtsbp_y_raw = 0
     .whtsbp_x_raw = 0
     .las = get_tpar("las", tpar_list = .tpars, default = par("las"))
+    # Same reasoning for the log state: par("xlog")/par("ylog") still describe
+    # the previous plot on this device until plot.window() runs, which is after
+    # this block. Read the user's `log` argument instead (#725).
+    .xlog = grepl("x", log, fixed = TRUE)
+    .ylog = grepl("y", log, fixed = TRUE)
     # A flipped boxplot draws the x variable up the side and the y variable
     # along the bottom, so a rotation has to be measured against the side its
     # labels actually land on. (The las branches below keep indexing 1/2
@@ -1328,7 +1333,7 @@ tinyplot.default = function(
     if (!is.null(yaxr) || .las %in% 1:2) {
       yaxlabs = axis_tick_labels(
         y_axis_labels(type, y, ylabs, xlabs, flip),
-        lim = ylim, axb = yaxb, axl = yaxl, log = par("ylog"),
+        lim = ylim, axb = yaxb, axl = yaxl, log = .ylog,
         cex = .cex_yaxs
       )
       if (!is.null(yaxr)) {
@@ -1343,7 +1348,7 @@ tinyplot.default = function(
     if (!is.null(xaxr) || .las %in% 2:3) {
       xaxlabs = axis_tick_labels(
         x_axis_labels(xlabs),
-        lim = xlim, axb = xaxb, axl = xaxl, log = par("xlog"),
+        lim = xlim, axb = xaxb, axl = xaxl, log = .xlog,
         cex = .cex_xaxs
       )
       if (!is.null(xaxr)) {
@@ -1387,17 +1392,25 @@ tinyplot.default = function(
       max(0, fin / par("csi") - pad)
     }
     if (!is.null(xaxr)) {
+      .u = axis_usr(xlim, log = .xlog, axb = xaxb)
       .at = if (!is.null(xlabs)) as.numeric(xlabs) else
-        axisTicks(usr = extendrange(xlim, f = 0.04), log = par("xlog"))
-      .ins = axis_tick_inset(.at, extendrange(xlim, f = 0.04), .span("x"))
+        axisTicks(usr = .u[["usr"]], log = .u[["log"]])
+      # axisTicks() reports tick locations in data units, but the inset is a
+      # visual fraction of the panel, so both sides of it live in usr space.
+      if (.u[["log"]]) .at = log10(.at)
+      .ins = axis_tick_inset(.at, .u[["usr"]], .span("x"))
       .ovh = tick_label_overhang(xaxlabs, cex = .cex_xaxs, srt = xaxr,
                                  side = .xside, inset = .ins)
       .dyn = .add_lean(.dyn, .ovh, .flank(.xside))
     }
     if (!is.null(yaxr)) {
+      .u = axis_usr(ylim, log = .ylog, axb = yaxb)
       .at = if (!is.null(ylabs)) as.numeric(ylabs) else
-        axisTicks(usr = extendrange(ylim, f = 0.04), log = par("ylog"))
-      .ins = axis_tick_inset(.at, extendrange(ylim, f = 0.04), .span("y"))
+        axisTicks(usr = .u[["usr"]], log = .u[["log"]])
+      # axisTicks() reports tick locations in data units, but the inset is a
+      # visual fraction of the panel, so both sides of it live in usr space.
+      if (.u[["log"]]) .at = log10(.at)
+      .ins = axis_tick_inset(.at, .u[["usr"]], .span("y"))
       .ovh = tick_label_overhang(yaxlabs, cex = .cex_yaxs, srt = yaxr,
                                  side = .yside, inset = .ins)
       .dyn = .add_lean(.dyn, .ovh, .flank(.yside))

inst/tinytest/test-tinyAxis.R

@@ -36,3 +36,13 @@ f = function() {
            xaxl = cyl_labs, xaxr = 45, theme = "clean")
 }
 expect_snapshot_plot(f, label = "axis_rotation_flip")
+
+
+# Dynmar with repeated log calls (#725)
+f = function() {
+  tinytheme("ipsum")
+  on.exit(tinytheme())
+  plt(disp ~ mpg, data = mtcars, log = "y")
+  plt(disp ~ mpg, data = mtcars, log = "y")
+}
+expect_silent(f())