size now sets default error_[x/y].width and span sets error_[x/y].thickness; closes #1226

Author: cpsievert

NEWS.md

@@ -13,6 +13,7 @@
 
 * The `color` argument now maps to `fillcolor`, making it much easier to use polygon fills to encode data values (e.g., choropleth maps). For backwards-compatibilty reasons, when `color` maps to `fillcolor`, `alpha` defaults to 0.5 (instead of 1). For an example, `plot_mapbox(mn_res, color = ~INDRESNAME)` or `plot_mapbox(mn_res, split = ~INDRESNAME, color = ~AREA, showlegend = FALSE, stroke = I("black"))`.
 * The `color` argument no longer automatically add `"markers"` to the `mode` attribute for scatter/scattergl trace types. Those who wish to have the old behavior back, should add `"markers"` to the `mode` explicity (e.g., change `plot_ly(economics, x = ~pce, y = ~pop, color = ~as.numeric(date), mode = "lines")` to `plot_ly(economics, x = ~pce, y = ~pop, color = ~as.numeric(date), mode = "lines+markers")`).
+* The `size` argument now informs a default [error_[x/y].width](https://plot.ly/r/reference/#scatter-error_x-width) (and `span` informs [error_[x/y].thickness](https://plot.ly/r/reference/#scatter-error_x-thickness)). Note you can override the default by specifying directly (e.g. `plot_ly(x = 1:10, y = 1:10, size = I(10), error_x = list(value = 5, width = 0))`)
 * `layout.showlegend` now defaults to `TRUE` for a *single* pie trace. This is a more sensible default and matches pure plotly.js behavior.
 * The `elementId` field is no longer populated, which fixes the "Ignoring explicitly provided widget ID" warning in shiny applications (see #985).
 

R/plotly.R

@@ -53,12 +53,16 @@
 #' @param linetypes A character vector of `lty` values or [dash names](https://plot.ly/r/reference#scatter-line-dash)
 #' @param size (Numeric) values mapped to relevant 'fill-size' attribute(s) 
 #' (e.g., [marker.size](https://plot.ly/r/reference#scatter-marker-size), 
-#' [textfont.size](https://plot.ly/r/reference#scatter-textfont-size), etc).
+#' [textfont.size](https://plot.ly/r/reference#scatter-textfont-size),
+#' and [error_x.width](https://plot.ly/r/reference#scatter-error_x-width)).
 #' The mapping from data values to symbols may be controlled using
 #' `sizes`, or avoided altogether via [I()] (e.g., `size = I(30)`). 
 #' @param sizes A numeric vector of length 2 used to scale `size` to pixels.
 #' @param span (Numeric) values mapped to relevant 'stroke-size' attribute(s) 
-#' (e.g., [marker.line.width](https://plot.ly/r/reference#scatter-marker-line-width))
+#' (e.g., 
+#' [marker.line.width](https://plot.ly/r/reference#scatter-marker-line-width),
+#' [line.width](https://plot.ly/r/reference#scatter-line-width) for filled polygons,
+#' and [error_x.thickness](https://plot.ly/r/reference#scatter-error_x-thickness))
 #' The mapping from data values to symbols may be controlled using
 #' `spans`, or avoided altogether via [I()] (e.g., `span = I(30)`). 
 #' @param spans A numeric vector of length 2 used to scale `span` to pixels.

R/plotly_build.R

@@ -564,18 +564,29 @@ map_size <- function(traces, stroke = FALSE) {
       isSingular <- length(size_) == 1
       attrs <- Schema$traces[[type]]$attributes
 
+      # `span` controls marker.line.width
       if (has_attr(type, "marker")) {
         s <- if (isSingular) size_ else if (array_ok(attrs$marker$line$width)) sizes
         trace$marker$line <- modify_list(list(width = default(s)), trace$marker$line)
       }
+      
+      # `span` controls error_[x/y].thickness 
+      for (attr in c("error_y", "error_x")) {
+        if (!has_attr(type, attr)) next
+        s <- if (isSingular) size_ else if (array_ok(attrs[[attr]]$thickness)) sizes
+        trace[[attr]] <- modify_list(list(thickness = default(s)), trace[[attr]])
+      }
+      
+      # When fill exists, `span` controls line.width
       if (has_fill(trace) && has_attr(type, "line")) {
-        s <- if (isSingular) size_ else if (array_ok(attrs$line$width)) sizes
-        if (is.null(s)) {
+        s <- if (isSingular) size_ else if (array_ok(attrs$line$width)) sizes else NA
+        if (is.na(s)) {
           warning("`line.width` does not currently support multiple values.", call. = FALSE)
         } else {
           trace[["line"]] <- modify_list(list(width = default(s)), trace[["line"]])
         }
       }
+      
       trace
     }, 
     size = function(trace, sizes) {
@@ -584,30 +595,34 @@ map_size <- function(traces, stroke = FALSE) {
       isSingular <- length(size_) == 1
       attrs <- Schema$traces[[type]]$attributes
 
-      # size controls marker.size (note 'bar' traces have marker but not marker.size)
+      # `size` controls marker.size (note 'bar' traces have marker but not marker.size)
       # TODO: always ensure an array? https://github.com/ropensci/plotly/pull/1176
       if (has_attr(type, "marker") && "size" %in% names(attrs$marker)) {
         s <- if (isSingular) size_ else if (array_ok(attrs$marker$size)) sizes
         trace$marker <- modify_list(list(size = default(s), sizemode = default("area")), trace$marker)
       }
 
-      # size controls textfont.size
+      # `size` controls textfont.size
       if (has_attr(type, "textfont")) {
         s <- if (isSingular) size_ else if (array_ok(attrs$textfont$size)) sizes
         trace$textfont <- modify_list(list(size = default(s)), trace$textfont)
       }
 
-      # TODO: should size set error_x.value?
-      #for (attr in c("error_y", "error_x")) {
-      #  if (!has_attr(type, attr)) next
-      #  s <- if (isSingular) size_ else if (array_ok(attrs[[attr]]$width)) sizes
-      #  trace[[attr]] <- modify_list(list(width = default(s)), trace[[attr]])
-      #}
+      # `size` controls error_[x/y].width 
+      for (attr in c("error_y", "error_x")) {
+        if (!has_attr(type, attr)) next
+        s <- if (isSingular) size_ else if (array_ok(attrs[[attr]]$width)) sizes
+        trace[[attr]] <- modify_list(list(width = default(s)), trace[[attr]])
+      }
 
-      # if fill does not exist, size controls line.width
+      # if fill does not exist, `size` controls line.width
       if (!has_fill(trace) && has_attr(type, "line")) {
-        s <- if (isSingular) size_ else if (array_ok(attrs$line$color)) sizes
-        trace[["line"]] <- modify_list(list(width = default(s)), trace[["line"]])
+        s <- if (isSingular) size_ else if (array_ok(attrs$line$width)) sizes else NA
+        if (is.na(s)) {
+          warning("`line.width` does not currently support multiple values.", call. = FALSE)
+        } else {
+          trace[["line"]] <- modify_list(list(width = default(s)), trace[["line"]])
+        }
       }
       trace
     }
@@ -692,23 +707,33 @@ map_color <- function(traces, stroke = FALSE, title = "", colorway, na.color = "
       attrs <- Schema$traces[[type]]$attributes
       default_ <- if (is_colorway) function(x) prefix_class(default(x), "colorway") else default
 
+      # `color` controls marker.color, textfont.color, error_[x/y].color
       # TODO: any more attributes that make sense to include here?
       for (attr in c("marker", "textfont", "error_y", "error_x")) {
         if (!has_attr(type, attr)) next
         if (is_colorway && "textfont" == attr) next
-        col <- if (isSingular) rgba_ else if (array_ok(attrs[[attr]]$color)) rgba
-        trace[[attr]] <- modify_list(list(color = default_(col)), trace[[attr]])
+        col <- if (isSingular) rgba_ else if (array_ok(attrs[[attr]]$color)) rgba else NA
+        if (is.na(col)) {
+          warning("`", attr, ".color` does not currently support multiple values.", call. = FALSE)
+        } else {
+          trace[[attr]] <- modify_list(list(color = default_(col)), trace[[attr]])
+        }
       }
 
+      # If trace has fill, `color` controls fillcolor; otherwise line.color
       if (has_fill(trace)) {
         if (!isSingular) warning("Only one fillcolor per trace allowed", call. = FALSE)
         # alpha defaults to 0.5 when applied to fillcolor
         if (is.null(trace[["alpha"]])) rgba_ <- toRGB(rgba_, 0.5)
         if (isSingular) trace <- modify_list(list(fillcolor = default_(rgba_)), trace)
       } else if (has_attr(type, "line")) {
         # if fill does not exist, 'color' controls line.color
-        col <- if (isSingular) rgba_ else if (array_ok(attrs$line$color)) rgba
-        trace[["line"]] <- modify_list(list(color = default_(col)), trace[["line"]])
+        col <- if (isSingular) rgba_ else if (array_ok(attrs$line$color)) rgba else NA
+        if (is.na(col)) {
+          warning("`line.color` does not currently support multiple values.", call. = FALSE)
+        } else {
+          trace[["line"]] <- modify_list(list(color = default_(col)), trace[["line"]])
+        }
       }
       trace
     }

man/plot_ly.Rd

@@ -189,3 +189,23 @@ test_that("Complex example works", {
 
   l <- expect_traces(p, 3, "time-series-summary")
 })
+
+
+test_that("span/size controls errorbar thickness/width", {
+  
+  p <- plot_ly(x = 1:10, y = 1:10, error_x = list(value = 3), error_y = list(value = 2), span = I(5), size = I(10), stroke = I("black"), color = I("red")) %>%
+    plotly_build()
+  
+  d <- p$x$data
+  expect_length(d, 1)
+  
+  expect_true(d[[1]]$error_x$value == 3)
+  expect_true(d[[1]]$error_x$thickness == 5)
+  expect_true(d[[1]]$error_x$width == 10)
+  expect_true(d[[1]]$error_x$color == toRGB("red"))
+  
+  expect_true(d[[1]]$error_y$value == 2)
+  expect_true(d[[1]]$error_y$thickness == 5)
+  expect_true(d[[1]]$error_y$width == 10)
+  expect_true(d[[1]]$error_y$color == toRGB("red"))
+})