Same Width of two different gtables - r

Question

(I want to have a gtable object with some data, a header and a footnote.
Each of the three elements are gtables, which are combinded to one gtable-object using gtable_add_rows first, and then gtable_add_grob to arrange the three gtables into one grob. Unfortunately the headline/footnote is too long (resp. too short)
How can I set the width of headline/ footline ?
How can I assign the text of headline/ footline to left-alignment?
My code example:
require(gtable)
require(grid)
require(gridExtra)
tbl<-matrix(paste(letters[1:6]),nrow=2)
colnames(tbl)<-c(paste0("col",1:3))
rownames(tbl)<-c(paste0("row",1:2))
tbl
tt1 <- ttheme_default(base_size = 10,rowhead=list(fg_params=list(fontface=2,hjust=0, x=0)))
tt2 <- ttheme_default(base_size = 15,fg_params=list(fontface="bold",hjust=1,x=0.9))
tt3 <- ttheme_default(base_size =7, fg_paras=list(fontface="italic",hjust=0,x=0.9))
gtbl <- tableGrob(tbl, theme=tt1)
htxt <- tableGrob("Headline is too long and this is stupid", theme=tt2)
ftxt <- tableGrob("Footnote", theme=tt3)
padding <- unit(1,"line")
table <- gtable_add_rows(gtbl,
heights = grobHeight(htxt) + padding,
pos = 0)
table <- gtable_add_rows(table,
heights = grobHeight(ftxt)+ padding)
table <- gtable_add_grob(table, list(htxt, ftxt),
t=c(1, nrow(table)), l=c(1,1),
r=ncol(table))
dim(table)
grid.newpage()
grid.draw(table)
Thanks for any help!
Volker

Answer 1

I solved my problem.
Only two minor problems are left. See below my commented code.
# load packages ------------------------------------------------------------
require(gtable)
require(grid)
require(gridExtra)
# id makro ----------------------------------------------------------------
# see here: https://stackoverflow.com/questions/43613320/how-to-add-multi-sub-columns-in-gridextratablegrob/43620247#43620247
# Tanks to: baptiste
id_cell <- function(table, row, col, name="colhead-fg"){
l <- table$layout
which(l$t %in% row & l$l %in% col & l$name==name)
}
# code to test it----------------------------------------------------------------
# Some different table themes
tt1 <- ttheme_default(base_size = 10,rowhead=list(fg_params=list(fontface=2,hjust=0, x=0))) # Data
tt2 <- ttheme_default(base_size = 15,fg_params=list(fontface="bold",hjust=1,x=0.9)) # Header
tt3 <- ttheme_default(base_size = 7,fg_params=list(fontface="italic",hjust=0,x=0.9)) # Footnote
# Convert to gtable
# 1. Data
# The data
tbl<-matrix(paste(letters[1:6]),nrow=2)
colnames(tbl)<-c("col1","column2","verywidecolum3")
rownames(tbl)<-c(paste0("row",1:2))
gtbl <- tableGrob(tbl, theme=tt1)
# 2. Headline
# Note: Define the Headline as gtable with as many columns a your Data
# Headline is defined in last colum due to the Makro id_cells.
hl<-"Headline"
hlm<-matrix(c(rep("",(dim(gtbl)[2]-1)),hl),nrow=1)
hlm
htxt <- tableGrob(hlm, theme=tt2)
# 3. Footnote
# Note: Define the Footnote as gtable with as many columns a your Data
# The text of your footnote is defined in last colum due to the Makro id_cells.
ftm<-matrix(c(rep("",(dim(gtbl)[2]-1)),"Footnote"),nrow=1)
ftxt <- tableGrob(ftm, theme=tt3)
# Define your table with Headline, Data and Footnote in one gtable object
tab2<-combine(htxt,gtbl,ftxt,along=2)
# Draw Grid - not formated
grid.newpage()
grid.draw(tab2)
# Formating of Grid Table
# Adjust columnwidths: same widths for each column
tab2$widths <- unit(rep(1/ncol(tab2), ncol(tab2)), "null")
#
rowg<-dim(tab2)[1] # Number of rows of your gtable
colg<-dim(tab2)[2] # Number of columns of your gtable
eleg<-2*rowg*colg # Number of grobs of your gtable
# Note: Grobs in gtables are arranged in rows. Within each row first grob class "text" is repeated for the columns of gtable, then grob class "rect"
# Identify Grob elements which should be formated
# This is Headline and footnote,
forg<-c(1:colg,(eleg-2*colg+1):(eleg-colg));forg
for (i in forg){
if ((class(tab2$grobs[[i]])=="text")[1] == TRUE) {
print(i)
tab2$grobs[[i]]$x<-unit(0,"npc")
tab2$grobs[[i]]$hjust<-0
}
}
# Headline over all cells
idh <- id_cell(tab2, 1, colg,"core-fg")
tab2$layout[idh,"l"] <- tab2$layout[idh,"l"] - (colg-1)
# Footnote over all cells
idf <- id_cell(tab2, rowg, colg,"core-fg")
tab2$layout[idf,"l"] <- tab2$layout[idf,"l"] - (colg-1)
# Draw grid
grid.newpage()
grid.draw(tab2)
My two minor problems:
a) This code
tab2$widths <- unit(rep(1/ncol(tab2), ncol(tab2)), "null")
makes the same widths for each column. But it seems, that it is not the minimal needed columnwidth. In my example it is the minimum needed width of the last column. How to fit the columns with the minimal needed columnwidth, so that each column has the same width?
b) How to change babtistes function id_cell,
# id makro ----------------------------------------------------------------
# see here: https://stackoverflow.com/questions/43613320/how-to-add-multi-sub-columns-in-gridextratablegrob/43620247#43620247
# Tanks to: baptiste
id_cell <- function(table, row, col, name="colhead-fg"){
l <- table$layout
which(l$t %in% row & l$l %in% col & l$name==name)
}
that it is possible to specify first the header/footnote an then the neccessary empty cells?
This is related to this code section:
# 2. Headline
# Note: Define the Headline as gtable with as many columns a your Data
# Headline is defined in last colum due to the Makro id_cells.
hl<-"Headline"
hlm<-matrix(c(rep("",(dim(gtbl)[2]-1)),hl),nrow=1)
htxt <- tableGrob(hlm, theme=tt2)
and
# Headline over all cells
idh <- id_cell(tab2, 1, colg,"core-fg")
tab2$layout[idh,"l"] <- tab2$layout[idh,"l"] - (colg-1)