与其他绘制森林图的包相比，forestploter将森林图视为表格，元素按行和列对齐。可以调整森林图中显示的内容和方式，并且可以分组多列显示置信区间。森林图的布局由所提供的数据集决定。
基本的森林图
森林图中的文本
数据的列名将绘制为表头，数据中的内容将显示在森林图中。应提供一个或多个不带任何内容的空白列以绘制置信区间（CI）。绘制 CI 的空间由此列的宽度确定。 首先准备绘图数据
代码语言：javascript复制library(grid)
library(forestploter)
# Read provided sample example data
dt <- read.csv(system.file("extdata", "example_data.csv", package = "forestploter"))
# Keep needed columns
dt <- dt[,1:6]
# indent the subgroup if there is a number in the placebo column
dt$Subgroup <- ifelse(is.na(dt$Placebo),
dt$Subgroup,
paste0(" ", dt$Subgroup))
# NA to blank or NA will be transformed to carachter.
dt$Treatment <- ifelse(is.na(dt$Treatment), "", dt$Treatment)
dt$Placebo <- ifelse(is.na(dt$Placebo), "", dt$Placebo)
dt$se <- (log(dt$hi) - log(dt$est))/1.96
# Add blank column for the forest plot to display CI.
# Adjust the column width with space.
dt$` ` <- paste(rep(" ", 20), collapse = " ")
# Create confidence interval column to display
dt$`HR (95% CI)` <- ifelse(is.na(dt$se), "",
sprintf("%.2f (%.2f to %.2f)",
dt$est, dt$low, dt$hi))
head(dt)
#> Subgroup Treatment Placebo est low hi se
#> 1 All Patients 781 780 1.869694 0.13245636 3.606932 0.3352463
#> 2 Sex NA NA NA NA
#> 3 Male 535 548 1.449472 0.06834426 2.830600 0.3414741
#> 4 Female 246 232 2.275120 0.50768005 4.042560 0.2932884
#> 5 Age NA NA NA NA
#> 6 <65 yr 297 333 1.509242 0.67029394 2.348190 0.2255292
#> HR (95% CI)
#> 1 1.87 (0.13 to 3.61)
#> 2
#> 3 1.45 (0.07 to 2.83)
#> 4 2.28 (0.51 to 4.04)
#> 5
#> 6 1.51 (0.67 to 2.35)
应用主题绘制简单的森林图
代码语言：javascript复制p <- forest(dt[,c(1:3, 8:9)],
est = dt$est,
lower = dt$low,
upper = dt$hi,
sizes = dt$se,
ci_column = 4,
ref_line = 1,
arrow_lab = c("Placebo Better", "Treatment Better"),
xlim = c(0, 4),
ticks_at = c(0.5, 1, 2, 3),
footnote = "This is the demo data. Please feel free to changenanything you want.")
# Print plot
plot(p)
更改主题背景
增加汇总列并修改图形参数
代码语言：javascript复制dt_tmp <- rbind(dt[-1, ], dt[1, ])
dt_tmp[nrow(dt_tmp), 1] <- "Overall"
# Define theme
tm <- forest_theme(base_size = 10,
# Confidence interval point shape, line type/color/width
ci_pch = 16,
ci_col = "#762a83",
ci_lty = 1,
ci_lwd = 1.5,
ci_Theight = 0.2, # Set an T end at the end of CI
# Reference line width/type/color
refline_lwd = 1,
refline_lty = "dashed",
refline_col = "grey20",
# Vertical line width/type/color
vertline_lwd = 1,
vertline_lty = "dashed",
vertline_col = "grey20",
# Change summary color for filling and borders
summary_fill = "#4575b4",
summary_col = "#4575b4",
# Footnote font size/face/color
footnote_cex = 0.6,
footnote_fontface = "italic",
footnote_col = "blue")
pt <- forest(dt_tmp[,c(1:3, 8:9)],
est = dt_tmp$est,
lower = dt_tmp$low,
upper = dt_tmp$hi,
sizes = dt_tmp$se,
is_summary = c(rep(FALSE, nrow(dt_tmp)-1), TRUE),
ci_column = 4,
ref_line = 1,
arrow_lab = c("Placebo Better", "Treatment Better"),
xlim = c(0, 4),
ticks_at = c(0.5, 1, 2, 3),
footnote = "This is the demo data. Please feel free to changenanything you want.",
theme = tm)
# Print plot
plot(pt)
编辑森林图
edit_plot可用于更改某些列或行的颜色或字体。 add_underline该函数可用于向特定行添加边框。 add_text该函数可用于向某些行/列添加文本。 insert_text该函数可用于在某一行之前或之后插入行并添加文本。
代码语言：javascript复制# Change text color in row 3
g <- edit_plot(p, row = 3, gp = gpar(col = "red", fontface = "italic"))
# Bold grouping text
g <- edit_plot(g,
row = c(2, 5, 10, 13, 17, 20),
gp = gpar(fontface = "bold"))
# Edit background of row 5
g <- edit_plot(g, row = 5, which = "background",
gp = gpar(fill = "darkolivegreen1"))
# Insert text at top
g <- insert_text(g,
text = "Treatment group",
col = 2:3,
part = "header",
gp = gpar(fontface = "bold"))
# Add underline at the bottom of the header
g <- add_underline(g, part = "header")
# Insert text
g <- insert_text(g,
text = "This is a long text. Age and gender summarised above.nBMI is next",
row = 10,
just = "left",
gp = gpar(cex = 0.6, col = "green", fontface = "italic"))
plot(g)
多个 CI 列
对于更复杂的示例，比如按组绘制CI。只需提供另一组est，lower和upper。如果提供的est、lower和upper的数目大于绘制CI的列号，则est、lower和upper将被重用。如下例所示，est_gp1和est_gp2将画在第3列和第5列中。但是est_gp3和est_gp4还没有被使用，它们将再次被绘制到第3列和第5列。因此，将est_gp1和est_gp2视为组1,est_gp3和est_gp4视为组2
代码语言：javascript复制# Add blank column for the second CI column
dt$` ` <- paste(rep(" ", 20), collapse = " ")
# Set-up theme
tm <- forest_theme(base_size = 10,
refline_col = "red",
footnote_col = "blue",
legend_name = "GP",
legend_value = c("Trt 1", "Trt 2"))
p <- forest(dt[,c(1:2, 20, 3, 22)],
est = list(dt$est_gp1,
dt$est_gp2,
dt$est_gp3,
dt$est_gp4),
lower = list(dt$low_gp1,
dt$low_gp2,
dt$low_gp3,
dt$low_gp4),
upper = list(dt$hi_gp1,
dt$hi_gp2,
dt$hi_gp3,
dt$hi_gp4),
ci_column = c(3, 5),
ref_line = 1,
arrow_lab = c("Placebo Better", "Treatment Better"),
nudge_y = 0.2,
xlog = TRUE,
theme = tm)
plot(p)
