When I was generating a a series of plots using package “survminer” in R, I often suffer from a blank page generated automatically at foremost of the PDF. For example:<\/p>\n\n\n\n
library(survival)\nlibrary(survminer)\n\n# Using lung dataset.\n\ncairo_pdf(filename = \".\/temp_plot.pdf\", onefile = TRUE)\nfor (single_sex in unique(lung$sex)) {\n lung_single_sex = subset(lung, sex == single_sex)\n cox_result = coxph(Surv(time, status) ~ age + ph.ecog, data = lung_single_sex)\n print(ggforest(cox_result, data = lung_single_sex))\n}\ndev.off()\n<\/code><\/pre>\n\n\n\nThen there will be three pages in temp_plot.pdf<\/code> and the first page will be blank.<\/p>\n\n\n\nI don’t know the exact reason of the issue. But it seems ggforest()<\/code> called ggpubr::as_ggplot()<\/code>, which called gridExtra:::grid.newpage()<\/code> or something similar, then caused the blank page before the plot. I searched the issue on the web and most people advised setting onefile = FALSE<\/code> in cairo_pdf()<\/code> to prevent the blank page. While it is not an ideal workaround because it makes the PDF contain only the last plot written to the file.<\/p>\n\n\n\nAfter some attempts, I found a relatively better workaround. The key is the plot(s) must be generated BEFORE<\/strong> (but not after) the PDF device opened. We can use a list to store the plot(s) which will be plotted on the PDF. For example:<\/p>\n\n\n\np_list = list() # To store the plots.\nfor (single_sex in unique(lung$sex)) {\n lung_single_sex = subset(lung, sex == single_sex)\n cox_result = coxph(Surv(time, status) ~ age + ph.ecog, data = lung_single_sex)\n p = ggforest(cox_result, data = lung_single_sex)\n p_list = c(p_list, list(p))\n}\ncairo_pdf(filename = \".\/temp_plot.pdf\", onefile = TRUE)\nfor (p in p_list) {\n print(p)\n}\ndev.off()<\/code><\/pre>\n\n\n\nThen the pages of PDF seem normal.<\/p>\n\n\n\n
References:<\/h2>\n\n\n\n
https:\/\/github.com\/hms-dbmi\/UpSetR\/issues\/90<\/a><\/p>\n\n\n\nhttps:\/\/github.com\/wilkelab\/cowplot\/issues\/24<\/a><\/p>\n\n\n\n