r - Change the position of the ticks in ggplot2 (inside the plot) -

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• how make axis ticks face inwards in ggplot2 1 answer

i change position of ticks of left plot right 1 (ticks inside plot).

library(ggplot2) library(grid)  p <- ggplot(mtcars,aes(mpg,cyl))+   geom_point() +    theme(         axis.ticks.length=unit(0.5,"cm"),         axis.line = element_line(color = 'black',size=0.1),         axis.ticks.y = element_line(size=1,color='red'),         axis.text.y = element_text(hjust=0.5)) 

i think can desired plot playing grobs surprise there not simple setting adjust ticks position!

edit (shift tick marks using solution here):

setting axis.ticks.length mentioned gives right solution , axis text should postioned more near axis. hjust has no effect.

p <- ggplot(mtcars,aes(mpg,cyl))+   geom_point() +    theme(     axis.ticks.length=unit(-0.25, "cm"),      axis.ticks.margin=unit(0.5, "cm"),     axis.line = element_line(color = 'black',size=0.1),     axis.ticks.y = element_line(size=1,color='red'),     axis.text.y = element_text(hjust=0.5)) ##this don't work 

here solution based on manipulating plot grobs. gives looking manipulating grobs...is never right way go (unreadable code)

adjust_ticks <-    function(pn,adj=0.5){     ## grobs      p <- p +theme(       axis.ticks.length=unit(adj,"cm")     )     gt <- ggplotgrob(p)     # row number of left axis in layout     rn <- which(gt$layout$name == "axis-l")     ## extract axis ticks grobs (text)     axis.grobs <- gt$grobs[[rn]]     axisb <- axis.grobs$children[[2]]       ## change position of ticks (text , ticks )     gt$grobs[[rn]]$children[[2]]$grobs[[2]]$x <- axisb$grobs[[2]]$x + unit(adj,"cm")     gt$grobs[[rn]]$children[[2]]$grobs[[1]]$x <- axisb$grobs[[1]]$x + unit(adj,"cm")     ## show differnce      gt   }  plot(adjust_ticks(p))