Dynamically Displaying Multiple Plots with Dygraphs in R
Dygraphs is a powerful JavaScript library for creating interactive time-series charts, often used in R through the dygraphs package. This article will guide you through a common use case: displaying multiple plots within a single dygraph and enabling dynamic control over their visibility using the dySeries option.
The Challenge: Managing Multiple Datasets
Imagine you have a dataset containing multiple time series, each representing a different variable or observation. You want to visualize these series together but allow users to easily switch between different combinations of plots. This is where the dySeries option comes in.
Setting the Scene: Code Example
Let's start with a basic example. We'll create a dygraph with two series:
library(dygraphs)
# Example dataset
time <- seq(as.Date("2023-01-01"), as.Date("2023-01-10"), by = "day")
data <- data.frame(
Date = time,
Series1 = runif(length(time), 10, 20),
Series2 = runif(length(time), 5, 15)
)
# Create the dygraph
dygraph(data, main = "Multiple Time Series") %>%
dySeries("Series1", label = "Series 1") %>%
dySeries("Series2", label = "Series 2")
This code generates a dygraph with both Series1 and Series2 visible. But how do we selectively show or hide these series?
Introducing dySeries for Dynamic Control
The dySeries option allows you to define the initial visibility of a series and provides methods for toggling visibility within the chart interface.
Here's how to modify our example to allow users to hide/show individual series:
dygraph(data, main = "Multiple Time Series") %>%
dySeries("Series1", label = "Series 1", show = TRUE) %>%
dySeries("Series2", label = "Series 2", show = TRUE) %>%
dyOptions(drawPoints = TRUE,
drawPointLabels = TRUE,
showRangeSelector = TRUE,
retainDateWindow = TRUE) %>%
dyLegend(show = "always", labelsSeparateLines = TRUE)
The show parameter within dySeries defines the initial visibility of each series (defaults to TRUE). We've also added some options for enhanced visualization like point labels and a range selector.
Key Points:
dySeries: Controls individual series visibility, allowing you to set initial state and provide toggle functionality.dyOptions: Used to configure various dygraph properties, including display settings, navigation, and interactivity.dyLegend: Controls the legend display, such as showing it always or only on hover.
Enhancing the User Experience
To make the dynamic control truly user-friendly, you can use dySeries to create a toggleable legend:
dygraph(data, main = "Multiple Time Series") %>%
dySeries("Series1", label = "Series 1", show = TRUE) %>%
dySeries("Series2", label = "Series 2", show = TRUE) %>%
dyOptions(drawPoints = TRUE,
drawPointLabels = TRUE,
showRangeSelector = TRUE,
retainDateWindow = TRUE) %>%
dyLegend(show = "always", labelsSeparateLines = TRUE) %>%
dyCallbacks(drawCallback = JS("function() {
// Get the dygraph object
var dygraph = this.g;
// Access the legend elements
var legendEntries = dygraph.legend_entries;
// Attach click event handlers
for (var i = 0; i < legendEntries.length; i++) {
legendEntries[i].addEventListener('click', function() {
var label = this.getElementsByClassName('dygraph-legend-label')[0].innerHTML;
dygraph.setVisibility(label, !dygraph.visibility()[label]);
});
}
}"))
This code adds JavaScript functionality to toggle the visibility of a series when its corresponding legend label is clicked.
Conclusion
Mastering the dySeries option allows you to craft dynamic and interactive dygraphs that display multiple time series with user-controlled visibility. This empowers you to create more engaging and insightful visualizations for your data.
Remember: Experiment with different dyOptions and explore the dyCallbacks feature to customize your dygraphs even further.
Additional Resources:
