I want to add an annotation to a plotly heatmap. There is a bug with the font parameter. I've followed the example given here.
library(plotly)
### heatmap data ###
x <- 1:3; y <- 3:5
dd <- transform(expand.grid(x=x, y=y), z=x+y)
### plotly graphic ###
pp <- plot_ly(data=dd, x=~x, y=~y, z=~z, type="heatmap",
hoverinfo = 'text',
text = ~paste('<em>x</em>: ', dd$x,
'</br> <em>y</em>: ', dd$y,
'</br> <em>z</em>: ', dd$z)) %>%
layout(xaxis=list(title="<em>xaxis title</em>"))
### add annotation ###
pp <- pp %>%
add_annotations( x = 1,
y = 4,
text = "<em>MY ANNOTATION</em>",
xref = "x",
yref = "y",
showarrow = TRUE,
arrowhead = 7,
ax = 10,
ay = 30,
font = list(color = 'red',
family = 'sans serif',
size = 24)
)
That does not yield the expected result:
In fact, the problem lies in the fact that plotly_build generates three annotation layouts, one for each parameter of the font list:
> bpp <- plotly_build(pp)
> annotation <- bpp$x$layout$annotations
> length(annotation)
[1] 3
> sapply(annotation, function(x) x$font)
[1] "red" "sans serif" "24"
Thus, here is a way to get the expected result:
myannotation <- annotation[[1]]
myannotation$font <- list(color = 'red',
family = 'sans serif',
size = 24)
bpp$x$layout$annotations <- myannotation
bpp
> packageVersion("plotly")
[1] ‘4.5.2’
I want to add an annotation to a plotly heatmap. There is a bug with the
fontparameter. I've followed the example given here.That does not yield the expected result:
In fact, the problem lies in the fact that
plotly_buildgenerates three annotation layouts, one for each parameter of thefontlist:Thus, here is a way to get the expected result: