R/lineplot.R

In Alanocallaghan/plotlyutils: Some utility functions for plotly

#' A line plot with selectable y variables.
#' @param df A data.frame
#' @param x The column name (as a string) of the x variable
#' @param yvars The column names (as strings) to be used as y variables
#' @return A plotly object
#' @examples
#' set.seed(42)
#' df <- lapply(1:26, function(x) rnorm(50))
#' df <- as.data.frame(df)
#' colnames(df) <- letters
#' df[["seq"]] <- 1:50
#' dropdown_lineplot(df, x="seq", yvars = letters)
#' @importFrom plotly add_lines add_trace
#' @importFrom magrittr %>%
#' @export
dropdown_lineplot <- function(df, x, yvars) {
    ## Add trace directly here, since plotly adds a blank trace otherwise
    p <- plot_ly(
        type = "scatter",
        mode = "lines",
        x = ~ df[[x]],
        y = ~ df[[yvars[[1]]]],
        name = yvars[[1]]
    )
    ## Add arbitrary number of traces
    ## Ignore first col as it has already been added
    for (col in yvars[-1]) {
        p <- p %>% add_lines(
            x = ~ df[[x]],
            y = df[[col]],
            name = col,
            visible = FALSE
        )
    }

    p %>%
        layout(
            title = "Dropdown line plot",
            xaxis = list(title = "x"),
            yaxis = list(title = "y"),
            updatemenus = list(
                list(
                    y = 0.7,
                    ## Add all buttons at once
                    buttons = lapply(yvars, function(col) {
                        list(
                            method = "restyle",
                            args = list("visible", yvars == col),
                            label = col
                        )
                    })
                )
            )
        )
}