How can I get tooltips showing in dygraphs without annotation
I am trying to use the R implementation of dygraphs
The example provided is
library(dygraphs)
dygraph(presidents, main = "Presidential Approval") %>%
dyAxis("y", valueRange = c(0, 100)) %>%
dyAnnotation("1950-7-1", text = "A", tooltip = "Korea") %>%
dyAnnotation("1965-1-1", text = "B", tooltip = "Vietnam")
which results in the chart 
Hovering over the 'A' produces a tooltip with 'Korea'
I am keen to have a tooltip for every point preferably dispensing entirely with the text requirement - though setting text to "" with minimal height/width values might suffice. I would also want to attach the dyAnnotations programmatically from a file with date and tooltip columns
df <- data.frame(date=as.Date(c("1950-7-1","1965-1-1")),tooltip=c("Korea","Vietnam"))
Is this feasible,and, if so, how? TIA
Alright, as promised, here is a start to how we might use the legend for your information. We crudely overwrite the legend. This behavior can be made much more polite if you also want a legend. In addition, you could provide an object/hash with a data.frame to lookup the x and return an informative description.
I added a debugger so if you open your debugger in Chrome, etc. you can see what is happening.
library(dygraphs)
dyG = dygraph(presidents, main = "Presidential Approval") %>%
dyAxis("y", valueRange = c(0, 100))
# explore the legend route
dyG %>%
dyCallbacks(
highlightCallback = sprintf(
'function(e, x, pts, row) {
// added to illustrate what is happening
// remove once satisfied with your code
debugger;
var customLegend = %s
// should get our htmlwidget
e.target.parentNode.parentNode
.querySelectorAll(".dygraph-legend")[0]
.innerText = customLegend[row] + row;
}'
,# supply a vector or text that you would like
jsonlite::toJSON(rep('something here',length(as.vector(presidents))))
)
)
Below, I have changed to add to the legend rather than replace.
# explore the legend route
# add to legend rather than replace
dyG %>%
dyCallbacks(
highlightCallback = sprintf(
'function(e, x, pts, row) {
// added to illustrate what is happening
// remove once satisfied with your code
debugger;
var customLegend = %s
// should get our htmlwidget
var legendel = e.target.parentNode.parentNode
.querySelectorAll(".dygraph-legend")[0];
// should get our htmlwidget
legendel.innerHTML = legendel.innerHTML + "<br>" + customLegend[row];
}'
,# supply a vector or text that you would like
jsonlite::toJSON(rep('something here',length(as.vector(presidents))))
)
)
Much of Dygraphs customization occurs in CSS styling. For example, here is how we can change the default tooltip behavior. With this in mind and a little help from Dygraphs annotation documentation, we can do something like this for the first question.
# answers Stack Overflow question
# http://stackoverflow.com/questions/27671576/how-can-i-get-tooltips-showing-in-dygraphs-without-annotation
# on how to customize annotations
library(dygraphs)
# question is two parts - let's handle part 1 first
dygraph(presidents, main = "Presidential Approval") %>%
dyAxis("y", valueRange = c(0, 100)) %>%
dyAnnotation("1950-7-1", text = "Korea", tooltip = ""
# this is not necessary but think it better to be specific
,cssClass = "specialAnnotation") %>%
# will leave this as before
dyAnnotation("1965-1-1", text = "Vietnam", tooltip = "") -> dyG
#this is a hack to set css directly
# dyCSS designed to read a text css file
dyG$x$css = "
/* if cssClass not assigned use .dygraphDefaultAnnotation */
/* !important is critical for the rules to be applied */
.specialAnnotation {
overflow: visible !important;
width: initial !important;
}
"
for the second question, here is one way we can accomplish this
# now for part 2
dyG = dygraph(presidents, main = "Presidential Approval") %>%
dyAxis("y", valueRange = c(0, 100))
tooltips = list(
list(x = "1950-7-1", tooltip = "", text = "Korea")
,list(x = "1965-1-1", tooltip = "", text = "Vietnam")
)
annotator <- function(x,y){
d = do.call(dyAnnotation,modifyList(list(dygraph=x),y))
return(d)
}
dyG = Reduce( annotator, tooltips, init=dyG )
#this is a hack to set css directly
# dyCSS designed to read a text css file
dyG$x$css = "
/* if cssClass not assigned use .dygraphDefaultAnnotation */
/* !important is critical for the rules to be applied */
.dygraphDefaultAnnotation {
overflow: visible !important;
width: initial !important;
border: none !important;
font-size: 200% !important;
}
"
dyG
上一篇: 理解c中的汇编代码