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I am unable to move the x-axis labels, including tick marsk, in a geom_tile to the right end of each tile, I would also like to add the zero at the left end. I have tried breaks and labels but with no luck. Also using breaks and labels doesn't really work.

I am trying to achieve what is done in this answer but the solution suggested doens't work. How to force the x-axis tick marks to appear at the end of bar in heatmap graph?

my data 

toplot=structure(list(year = c(125L, 250L, 375L, 500L, 625L, 750L, 875L, 
1000L, 1125L, 1250L, 125L, 250L, 375L, 500L, 625L, 750L, 875L, 
1000L, 1125L, 1250L, 125L, 250L, 375L, 500L, 625L, 750L, 875L, 
1000L, 1125L, 1250L, 125L, 250L, 375L, 500L, 625L, 750L, 875L, 
1000L, 1125L, 1250L, 125L, 250L, 375L, 500L, 625L, 750L, 875L, 
1000L, 1125L, 1250L, 125L, 250L, 375L, 500L, 625L, 750L, 875L, 
1000L, 1125L, 1250L, 125L, 250L, 375L, 500L, 625L, 750L, 875L, 
1000L, 1125L, 1250L, 125L, 250L, 375L, 500L, 625L, 750L, 875L, 
1000L, 1125L, 1250L), density = structure(c(1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 3L, 
3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 
4L, 4L, 4L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 
2L, 2L, 2L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 
3L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L), .Label = c("a", 
"b", "c", "d"), class = "factor"), value = c(-0.04, 
0.07, 0.01, -0.06, -0.05, 0.04, 0.13, 0.17, 0.19, 0.19, 0.02, 
0.27, 0.3, 0.3, 0.36, 0.35, 0.38, 0.5, 0.67, 0.77, -0.14, -0.08, 
-0.05, 0.18, 0.37, 0.4, 0.41, 0.44, 0.47, 0.73, -0.24, -0.73, 
-0.16, -0.06, -0.02, -0.04, -0.75, -0.74, -0.74, -0.74, -0.77, 
-0.17, -0.51, -0.57, -0.78, -0.79, -0.22, -0.21, -0.22, -0.73, 
-0.58, -0.53, -0.23, -0.24, -0.56, -0.25, -0.31, -0.34, -0.71, 
-0.42, -0.26, -0.25, -0.35, -0.34, -0.44, -0.44, -0.44, -0.45, 
-0.45, -0.45, -0.3, -0.44, -0.17, -0.18, -0.18, -0.18, -0.18, 
-0.48, -0.48, -0.48), type = structure(c(1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 
2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 
2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L), .Label = c("var1", 
"var2"), class = "factor")), .Names = c("year", "density", "value", 
"type"), row.names = c(NA, -80L), class = "data.frame")

my code

ggplot(toplot, aes(year, density)) + 
  geom_tile(aes(fill = value), colour = "black") + 
  scale_fill_gradientn(colours=c('#dc180a', 'orange', 'white', '#a0e100', '#2e7cff'),
                       values = rescale(c(-.5, 0, .8)), 
                       guide = "colorbar", limits = c(-.5, .8)) + 
  scale_x_continuous(breaks = seq(0, 1250, 250), expand = c(0, 0)) + 
  theme_bw(base_size = 20) + 
  theme(axis.text.x = element_text(), 
        axis.text.y = element_text(size = rel(1.1)),
        plot.title = element_text(hjust = 0.5)) + 
  facet_wrap(~type, ncol = 2) + 
  theme(strip.background = element_rect(fill = "#fafafa"))+ 
  theme(strip.text = element_text(colour = 'black'),
        panel.spacing = unit(1, "lines")) + 
  scale_y_discrete(expand = c(0, 0))
Z.Lin
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Herman Toothrot
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1 Answers1

3

geom_raster() (a special case for geom_tile() accepts values for hjust and vjust, which controls the position of each tile relative to its coordinates. It doesn't appear to accept colour as an aesthetic for tile outlines, but you can fake it by placing grid lines (appropriately spaced) over the tiles:

ggplot(toplot, aes(x = year, y = density)) + 
  geom_raster(aes(fill = value), hjust = 0) + 
  geom_hline(yintercept = seq_along(toplot$density) + 0.5) +
  scale_fill_gradientn(colours=c('#dc180a', 'orange', 'white', '#a0e100', '#2e7cff'),
                       values = rescale(c(-.5, 0, .8)),
                       guide = "colorbar", limits = c(-.5, .8)) +
  scale_x_continuous(breaks = seq(0, 1250, 250), expand = c(0, 0)) +
  facet_wrap(~type, ncol = 2) +
  theme_bw(base_size = 10) +
  theme(panel.spacing = unit(1, "lines"),
        panel.background = element_blank(),
        panel.grid.major.x = element_line(color = "black"),
        panel.grid.minor.x = element_line(color = "black"),
        panel.grid.major.y = element_blank(),
        panel.grid.minor.y = element_blank(),
        panel.ontop = TRUE,
        axis.text.x = element_text(hjust = 1)) +
  scale_y_discrete(expand = c(0, 0))

plot

Z.Lin
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  • Absolutely brilliant! I would have never thought of doing that. Do you know if it's possible to either move the 1250 to the left or to not display the 0 in the var2 facet? – Herman Toothrot May 14 '18 at 15:55
  • Glad it helped. :) Sounds like adding `axis.text.x = element_text(hjust = 1)` to `theme()` will achieve what you're asking for. I'll update my answer. – Z.Lin May 14 '18 at 16:01
  • There is also another slight problem. The a,b,c,d should be at the center of the cell not at the top or bottom. I have used this axis.text.y = element_text(vjust = 2) to center them. I guess I will also have to eliminate the y tick marks. – Herman Toothrot May 14 '18 at 16:10
  • 1
    Updated answer. This can be achieved by leaving `geom_raster`'s `vjust` to its default value (0.5), hiding the horizontal grid lines, & explicitly drawing horizontal lines using `geom_hline` at the X.5 positions instead. – Z.Lin May 14 '18 at 16:21