Simplify y-axis expression

The yaxis_expr() function captured the first argument as an expression and substituted that argument symbol into the y-axis expression to render. This was more complicated than necessary. Put all the logic into one single expression, instead of building multiple expressions and concatenating them together based on arguments to new_panel(). This required adding 'use_get_ylim', 'draw_left_yaxis', and 'draw_right_axis' into the panel environment. Adding 'use_get_ylim' to the panel environment means get_ylim() is only called once. This improves performance because each call to get_ylim() calls update_panels(). See #103.
joshuaulrich · Oct 5, 2023 · cc7c454 · cc7c454
1 parent 7429dd7
commit cc7c454
Showing 1 changed file with 48 additions and 71 deletions.
diff --git a/R/plot.R b/R/plot.R
@@ -1172,6 +1172,9 @@ new.replot_xts <- function(panel=1,asp=1,xlim=c(1,10),ylim=list(structure(c(1,10
       panel$ylim <- ylim
       panel$ylim_render <- ylim
       panel$is_ylim_fixed <- is_ylim_fixed
+      panel$use_get_ylim <- use_get_ylim
+      panel$draw_left_yaxis  <- ifelse(is.null(draw_left_yaxis),  Env$theme$lylab, draw_left_yaxis)
+      panel$draw_right_yaxis <- ifelse(is.null(draw_right_yaxis), Env$theme$rylab, draw_right_yaxis)
       panel$header <- header
 
       ### actions
@@ -1211,84 +1214,58 @@ new.replot_xts <- function(panel=1,asp=1,xlim=c(1,10),ylim=list(structure(c(1,10
       panel$add_action(header_expr, env = panel)
 
       ### y-axis
-      panel$y_grid_lines <-
-      function(ylim)
-      {
-          p <- pretty(ylim, Env$yaxis.ticks)
-          p <- p[p >= ylim[1] & p <= ylim[2]]
-          return(p)
-      }
+      yaxis_expr <- expression({
 
-      yaxis_expr <-
-      function(ylim_expr,
-               yaxis_left,
-               yaxis_right)
-      {
-
-          # y-axis grid lines
-          exp <- substitute({
-              segments(x0 = xlim[1], y0 = y_grid_lines(ylim_expr),
-                       x1 = xlim[2], y1 = y_grid_lines(ylim_expr),
-                       col = theme$grid,
-                       lwd = grid.ticks.lwd,
-                       lty = grid.ticks.lty)
-          }, list(ylim_expr = substitute(ylim_expr)))
-
-          # y-axis grid labels
-          if (yaxis_left) {
-              # left y-axis labels
-              exp <- c(exp,
-                  substitute({
-                      text(x = xlim[1],
-                           y = y_grid_lines(ylim_expr),
-                           labels = noquote(format(y_grid_lines(ylim_expr), justify = "right")),
-                           col = theme$labels,
-                           srt = theme$srt,
-                           offset = 0.5,
-                           pos = 2,
-                           cex = theme$cex.axis,
-                           xpd = TRUE)
-                  }, list(ylim_expr = substitute(ylim_expr)))
-              )
+          if (use_get_ylim) {
+              # re-calculate and override panel ylim
+              ylim <- get_ylim()
           }
 
-          if (yaxis_right) {
-              # right y-axis labels
-              exp <- c(exp,
-                  substitute({
-                      text(x = xlim[2],
-                           y = y_grid_lines(ylim_expr),
-                           labels = noquote(format(y_grid_lines(ylim_expr), justify = "right")),
-                           col = theme$labels,
-                           srt = theme$srt,
-                           offset = 0.5,
-                           pos = 4,
-                           cex = theme$cex.axis,
-                           xpd = TRUE)
-                  }, list(ylim_expr = substitute(ylim_expr)))
-              )
+          y_grid_lines <-
+          function(ylim)
+          {
+              p <- pretty(ylim, Env$yaxis.ticks)
+              p <- p[p >= ylim[1] & p <= ylim[2]]
+              return(p)
           }
 
-        ### y-axis labels
-        exp <- c(exp, expression(title(ylab = ylab[1], mgp = c(1, 1, 0))))
+          # y-axis grid lines
+          segments(x0 = xlim[1], y0 = y_grid_lines(ylim),
+                   x1 = xlim[2], y1 = y_grid_lines(ylim),
+                   col = theme$grid,
+                   lwd = grid.ticks.lwd,
+                   lty = grid.ticks.lty)
+
+          # left y-axis grid labels
+          if (draw_left_yaxis) {
+              text(x = xlim[1],
+                   y = y_grid_lines(ylim),
+                   labels = format(y_grid_lines(ylim), justify = "right"),
+                   col = theme$labels,
+                   srt = theme$srt,
+                   offset = 0.5,
+                   pos = 2,
+                   cex = theme$cex.axis,
+                   xpd = TRUE)
+          }
 
-        return(exp)
-      }
+          # right y-axis grid labels
+          if (draw_right_yaxis) {
+              text(x = xlim[2],
+                   y = y_grid_lines(ylim),
+                   labels = format(y_grid_lines(ylim), justify = "right"),
+                   col = theme$labels,
+                   srt = theme$srt,
+                   offset = 0.5,
+                   pos = 4,
+                   cex = theme$cex.axis,
+                   xpd = TRUE)
+          }
 
-      if (is.null(draw_left_yaxis)) {
-        draw_left_yaxis <- Env$theme$lylab
-      }
-      if (is.null(draw_right_yaxis)) {
-        draw_right_yaxis <- Env$theme$rylab
-      }
-      if (use_get_ylim) {
-          yaxis_action <- yaxis_expr(get_ylim(),
-                                     draw_left_yaxis, draw_right_yaxis)
-      } else {
-          yaxis_action <- yaxis_expr(ylim,
-                                     draw_left_yaxis, draw_right_yaxis)
-      }
-      panel$add_action(yaxis_action, env = panel, update_ylim = FALSE)
+          # y-axis label
+          title(ylab = ylab[1], mgp = c(1, 1, 0))
+      })
+      panel$add_action(yaxis_expr, env = panel, update_ylim = FALSE)
 
       # x-axis grid
       xaxis_action <- expression(x_grid_lines(xdata, grid.ticks.on, par("usr")[3:4]))