Extra pointrange and errorbar support

NEWS.md

@@ -1,4 +1,4 @@
-# plot2 0.0.2.9006 (development version)
+# plot2 0.0.2.9007 (development version)
 
 Breaking changes:
 
@@ -16,7 +16,8 @@ New features:
 - Both the `pch` and `lty` arguments now accept a "by" convenience keyword for
 automatically adjusting plot characters and line types by groups (#28,
 @grantmcdermott).
-- Point-range plots with `type="pointrange"` (#35 @vincentarelbundock)
+- Add support for `type="pointrange"` and `type="errobar"` plots (#35
+@vincentarelbundock and #40 @grantmcdermott)
 
 Bug fixes:
 

R/plot2.R

@@ -22,12 +22,14 @@
 #'   not be specified in the same call.
 #' @param data a data.frame (or list) from which the variables in formula
 #'   should be taken. A matrix is converted to a data frame.
-#' @param type 1-character string giving the type of plot desired. The
-#'   following values are possible, for details, see plot: "p" for points, "l"
+#' @param type character string giving the type of plot desired. Options are:
+#'    - The same set of 1-character values supported by plot: "p" for points, "l"
 #'   for lines, "b" for both points and lines, "c" for empty points joined by
 #'   lines, "o" for overplotted points and lines, "s" and "S" for stair steps
 #'   and "h" for histogram-like vertical lines. "n" does not produce
-#'   any points or lines. "pointrange" draws point-range plots.
+#'   any points or lines.
+#'   - Additional plot2 types: "pointrange" draws point range plots and
+#'   "errorbar" draws error bar plots.
 #' @param xlim the x limits (x1, x2) of the plot. Note that x1 > x2 is allowed
 #'   and leads to a ‘reversed axis’. The default value, NULL, indicates that
 #'   the range of the `finite` values to be plotted should be used.
@@ -256,12 +258,27 @@ plot2.default = function(
   if (is.null(ylab)) ylab = deparse(substitute(y))
   if (is.null(legend.args$title)) ltitle = deparse(substitute(by))
 
+  xlabs = NULL  
+  if (type %in% c("pointrange", "errorbar")) {
+    if (is.character(x)) x = as.factor(x)
+    if (is.factor(x)) {
+      ## Need to maintain order that was observed in the original data
+      ## (i.e., no new sorting by factor)
+      xlvls = unique(x)
+      x = factor(x, levels = xlvls)
+      xlabs = seq_along(xlvls)
+      names(xlabs) = xlvls
+      x = as.integer(x)
+    }
+  }
+
   if (is.null(xlim)) xlim = range(x, na.rm = TRUE)
   if (is.null(ylim)) ylim = range(y, na.rm = TRUE)
 
   if (!is.null(ymin)) ylim[1] = min(c(ylim, ymin))
   if (!is.null(ymax)) ylim[2] = max(c(ylim, ymax))
 
+
   if (!is.null(by)) {
     l = list(x=x, y=y)
     l[["ymin"]] = ymin
@@ -401,14 +418,18 @@ plot2.default = function(
 
   # axes, plot.frame and grid
   if (axes) {
-    axis(1)
+    if (type %in% c("pointrange", "errorbar") && !is.null(xlabs)) {
+      axis(1, at = xlabs, labels = names(xlabs)) 
+    } else {
+      axis(1)  
+    }
     axis(2)
   }
   if (frame.plot) box()
   if (!is.null(grid)) grid
 
-  # draw the points/lines
-  if (type %in% "pointrange") { # segments before point
+  ## segments/arrows before points
+  if (type == "pointrange") { 
     invisible(
       lapply(
         seq_along(split_data),
@@ -417,13 +438,37 @@ plot2.default = function(
             x0 = seq_along(split_data[[i]]$x),
             y0 = split_data[[i]]$ymin,
             x1 = seq_along(split_data[[i]]$x),
-            y1 = split_data[[i]]$ymax
+            y1 = split_data[[i]]$ymax,
+            col = col[i],
+            lty = lty[i]
+          )
+        }
+      )
+    )
+  } 
+  if (type == "errorbar") { 
+    invisible(
+      lapply(
+        seq_along(split_data),
+        function(i) {
+          graphics::arrows(
+            x0 = seq_along(split_data[[i]]$x),
+            y0 = split_data[[i]]$ymin,
+            x1 = seq_along(split_data[[i]]$x),
+            y1 = split_data[[i]]$ymax,
+            col = col[i],
+            lty = lty[i],
+            length = 0.05,
+            angle = 90,
+            code = 3
           )
         }
       )
     )
   } 
-  if (type %in% c("p", "pointrange")) {
+
+  ## now draw the points/lines
+  if (type %in% c("p", "pointrange", "errorbar")) {
     invisible(
       lapply(
         seq_along(split_data),

README.Rmd

@@ -227,21 +227,25 @@ with(airquality, plot2(
 ))
 ```
 
-### Point-range
+### Point range and error bar plots
 
-`plot2` adds a new `type="pointrange"` option to draw point-ranges plots:
+`plot2` adds supports for point range and error bar plots via the `"pointrange"`
+and `"errorbar"` type arguments. An obvious use-case is for regression
+coefficient plots.
 
 ```{r pointrange, warning = FALSE}
-mod = lm(mpg ~ hp + factor(cyl), mtcars)
+mod = lm(Temp ~ 0 + factor(Month), airquality)
 coefs = data.frame(names(coef(mod)), coef(mod), confint(mod))
-coefs = setNames(coefs, c("x", "y", "ymin", "ymax"))
-with(coefs,
-  plot2(pch = 17,
-        x = 1:4,
-        y = y,
-        ymin = ymin,
-        ymax = ymax,
-        type = "pointrange"
+coefs = setNames(coefs, c("term", "estimate", "ci_low", "ci_high"))
+
+with(
+  coefs,
+  plot2(
+    x = term, y = estimate,
+    ymin = ci_low, ymax = ci_high,
+    type = "pointrange",
+    pch = 19,
+    main = "Effect on Temperature"
   )
 )
 ```

README.md

@@ -234,22 +234,25 @@ with(airquality, plot2(
 
 <img src="man/figures/README-desnity_topright-1.png" width="100%" />
 
-### Point-range
+### Point range and error bar plots
 
-`plot2` adds a new `type="pointrange"` option to draw point-ranges
-plots:
+`plot2` adds supports for point range and error bar plots via the
+`"pointrange"` and `"errorbar"` type arguments. An obvious use-case is
+for regression coefficient plots.
 
 ``` r
-mod = lm(mpg ~ hp + factor(cyl), mtcars)
+mod = lm(Temp ~ 0 + factor(Month), airquality)
 coefs = data.frame(names(coef(mod)), coef(mod), confint(mod))
-coefs = setNames(coefs, c("x", "y", "ymin", "ymax"))
-with(coefs,
-  plot2(pch = 17,
-        x = 1:4,
-        y = y,
-        ymin = ymin,
-        ymax = ymax,
-        type = "pointrange"
+coefs = setNames(coefs, c("term", "estimate", "ci_low", "ci_high"))
+
+with(
+  coefs,
+  plot2(
+    x = term, y = estimate,
+    ymin = ci_low, ymax = ci_high,
+    type = "pointrange",
+    pch = 19,
+    main = "Effect on Temperature"
   )
 )
 ```

inst/tinytest/test-README.R

@@ -100,6 +100,23 @@ f = function() {
 }
 expect_snapshot_plot(f, label = "readme_palette_tableau")
 
+f = function() {
+  mod = lm(Temp ~ 0 + factor(Month), airquality)
+  coefs = data.frame(names(coef(mod)), coef(mod), confint(mod))
+  coefs = setNames(coefs, c("term", "estimate", "ci_low", "ci_high"))
+  with(
+    coefs,
+    plot2(
+      x = term, y = estimate,
+      ymin = ci_low, ymax = ci_high,
+      type = "pointrange",
+      pch = 19,
+      main = "Effect on Temperature"
+    )
+  )
+}
+expect_snapshot_plot(f, label = "readme_pointrange")
+
 f = function() {
   par(pch = 16, family = "HersheySans")