prophet/R/R/plot.R
2017-12-22 13:36:46 -08:00

374 lines
13 KiB
R

#' Merge history and forecast for plotting.
#'
#' @param m Prophet object.
#' @param fcst Data frame returned by prophet predict.
#'
#' @importFrom dplyr "%>%"
#' @keywords internal
df_for_plotting <- function(m, fcst) {
# Make sure there is no y in fcst
fcst$y <- NULL
df <- m$history %>%
dplyr::select(ds, y) %>%
dplyr::full_join(fcst, by = "ds") %>%
dplyr::arrange(ds)
return(df)
}
#' Plot the prophet forecast.
#'
#' @param x Prophet object.
#' @param fcst Data frame returned by predict(m, df).
#' @param uncertainty Boolean indicating if the uncertainty interval for yhat
#' should be plotted. Must be present in fcst as yhat_lower and yhat_upper.
#' @param plot_cap Boolean indicating if the capacity should be shown in the
#' figure, if available.
#' @param xlabel Optional label for x-axis
#' @param ylabel Optional label for y-axis
#' @param ... additional arguments
#'
#' @return A ggplot2 plot.
#'
#' @examples
#' \dontrun{
#' history <- data.frame(ds = seq(as.Date('2015-01-01'), as.Date('2016-01-01'), by = 'd'),
#' y = sin(1:366/200) + rnorm(366)/10)
#' m <- prophet(history)
#' future <- make_future_dataframe(m, periods = 365)
#' forecast <- predict(m, future)
#' plot(m, forecast)
#' }
#'
#' @export
plot.prophet <- function(x, fcst, uncertainty = TRUE, plot_cap = TRUE,
xlabel = 'ds', ylabel = 'y', ...) {
df <- df_for_plotting(x, fcst)
gg <- ggplot2::ggplot(df, ggplot2::aes(x = ds, y = y)) +
ggplot2::labs(x = xlabel, y = ylabel)
if (exists('cap', where = df) && plot_cap) {
gg <- gg + ggplot2::geom_line(
ggplot2::aes(y = cap), linetype = 'dashed', na.rm = TRUE)
}
if (x$logistic.floor && exists('floor', where = df) && plot_cap) {
gg <- gg + ggplot2::geom_line(
ggplot2::aes(y = floor), linetype = 'dashed', na.rm = TRUE)
}
if (uncertainty && exists('yhat_lower', where = df)) {
gg <- gg +
ggplot2::geom_ribbon(ggplot2::aes(ymin = yhat_lower, ymax = yhat_upper),
alpha = 0.2,
fill = "#0072B2",
na.rm = TRUE)
}
gg <- gg +
ggplot2::geom_point(na.rm=TRUE) +
ggplot2::geom_line(ggplot2::aes(y = yhat), color = "#0072B2",
na.rm = TRUE) +
ggplot2::theme(aspect.ratio = 3 / 5)
return(gg)
}
#' Plot the components of a prophet forecast.
#' Prints a ggplot2 with panels for trend, weekly and yearly seasonalities if
#' present, and holidays if present.
#'
#' @param m Prophet object.
#' @param fcst Data frame returned by predict(m, df).
#' @param uncertainty Boolean indicating if the uncertainty interval should be
#' plotted for the trend, from fcst columns trend_lower and trend_upper.
#' @param plot_cap Boolean indicating if the capacity should be shown in the
#' figure, if available.
#' @param weekly_start Integer specifying the start day of the weekly
#' seasonality plot. 0 (default) starts the week on Sunday. 1 shifts by 1 day
#' to Monday, and so on.
#' @param yearly_start Integer specifying the start day of the yearly
#' seasonality plot. 0 (default) starts the year on Jan 1. 1 shifts by 1 day
#' to Jan 2, and so on.
#'
#' @return Invisibly return a list containing the plotted ggplot objects
#'
#' @export
#' @importFrom dplyr "%>%"
prophet_plot_components <- function(
m, fcst, uncertainty = TRUE, plot_cap = TRUE, weekly_start = 0,
yearly_start = 0
) {
# Plot the trend
panels <- list(plot_forecast_component(fcst, 'trend', uncertainty, plot_cap))
# Plot holiday components, if present.
if (!is.null(m$holidays) && ('holidays' %in% colnames(fcst))) {
panels[[length(panels) + 1]] <- plot_forecast_component(
fcst, 'holidays', uncertainty, FALSE)
}
# Plot weekly seasonality, if present
if ("weekly" %in% colnames(fcst)) {
panels[[length(panels) + 1]] <- plot_weekly(m, uncertainty, weekly_start)
}
# Plot yearly seasonality, if present
if ("yearly" %in% colnames(fcst)) {
panels[[length(panels) + 1]] <- plot_yearly(m, uncertainty, yearly_start)
}
# Plot other seasonalities
for (name in names(m$seasonalities)) {
if (!(name %in% c('weekly', 'yearly')) &&
(name %in% colnames(fcst))) {
panels[[length(panels) + 1]] <- plot_seasonality(m, name, uncertainty)
}
}
# Plot extra regressors
if ((length(m$extra_regressors) > 0)
& ('extra_regressors' %in% colnames(fcst))) {
panels[[length(panels) + 1]] <- plot_forecast_component(
fcst, 'extra_regressors', uncertainty, FALSE)
}
# Make the plot.
grid::grid.newpage()
grid::pushViewport(grid::viewport(layout = grid::grid.layout(length(panels),
1)))
for (i in seq_along(panels)) {
print(panels[[i]], vp = grid::viewport(layout.pos.row = i,
layout.pos.col = 1))
}
return(invisible(panels))
}
#' Plot a particular component of the forecast.
#'
#' @param fcst Dataframe output of `predict`.
#' @param name String name of the component to plot (column of fcst).
#' @param uncertainty Boolean to plot uncertainty intervals.
#' @param plot_cap Boolean indicating if the capacity should be shown in the
#' figure, if available.
#'
#' @return A ggplot2 plot.
#'
#' @export
plot_forecast_component <- function(
fcst, name, uncertainty = TRUE, plot_cap = FALSE
) {
gg.comp <- ggplot2::ggplot(
fcst, ggplot2::aes_string(x = 'ds', y = name, group = 1)) +
ggplot2::geom_line(color = "#0072B2", na.rm = TRUE)
if (exists('cap', where = fcst) && plot_cap) {
gg.comp <- gg.comp + ggplot2::geom_line(
ggplot2::aes(y = cap), linetype = 'dashed', na.rm = TRUE)
}
if (exists('floor', where = fcst) && plot_cap) {
gg.comp <- gg.comp + ggplot2::geom_line(
ggplot2::aes(y = floor), linetype = 'dashed', na.rm = TRUE)
}
if (uncertainty) {
gg.comp <- gg.comp +
ggplot2::geom_ribbon(
ggplot2::aes_string(
ymin = paste0(name, '_lower'), ymax = paste0(name, '_upper')
),
alpha = 0.2,
fill = "#0072B2",
na.rm = TRUE)
}
return(gg.comp)
}
#' Prepare dataframe for plotting seasonal components.
#'
#' @param m Prophet object.
#' @param ds Array of dates for column ds.
#'
#' @return A dataframe with seasonal components on ds.
#'
#' @keywords internal
seasonality_plot_df <- function(m, ds) {
df_list <- list(ds = ds, cap = 1, floor = 0)
for (name in names(m$extra_regressors)) {
df_list[[name]] <- 0
}
df <- as.data.frame(df_list)
df <- setup_dataframe(m, df)$df
return(df)
}
#' Plot the weekly component of the forecast.
#'
#' @param m Prophet model object
#' @param uncertainty Boolean to plot uncertainty intervals.
#' @param weekly_start Integer specifying the start day of the weekly
#' seasonality plot. 0 (default) starts the week on Sunday. 1 shifts by 1 day
#' to Monday, and so on.
#'
#' @return A ggplot2 plot.
#'
#' @keywords internal
plot_weekly <- function(m, uncertainty = TRUE, weekly_start = 0) {
# Compute weekly seasonality for a Sun-Sat sequence of dates.
days <- seq(set_date('2017-01-01'), by='d', length.out=7) + as.difftime(
weekly_start, units = "days")
df.w <- seasonality_plot_df(m, days)
seas <- predict_seasonal_components(m, df.w)
seas$dow <- factor(weekdays(df.w$ds), levels=weekdays(df.w$ds))
gg.weekly <- ggplot2::ggplot(seas, ggplot2::aes(x = dow, y = weekly,
group = 1)) +
ggplot2::geom_line(color = "#0072B2", na.rm = TRUE) +
ggplot2::labs(x = "Day of week")
if (uncertainty) {
gg.weekly <- gg.weekly +
ggplot2::geom_ribbon(ggplot2::aes(ymin = weekly_lower,
ymax = weekly_upper),
alpha = 0.2,
fill = "#0072B2",
na.rm = TRUE)
}
return(gg.weekly)
}
#' Plot the yearly component of the forecast.
#'
#' @param m Prophet model object.
#' @param uncertainty Boolean to plot uncertainty intervals.
#' @param yearly_start Integer specifying the start day of the yearly
#' seasonality plot. 0 (default) starts the year on Jan 1. 1 shifts by 1 day
#' to Jan 2, and so on.
#'
#' @return A ggplot2 plot.
#'
#' @keywords internal
plot_yearly <- function(m, uncertainty = TRUE, yearly_start = 0) {
# Compute yearly seasonality for a Jan 1 - Dec 31 sequence of dates.
days <- seq(set_date('2017-01-01'), by='d', length.out=365) + as.difftime(
yearly_start, units = "days")
df.y <- seasonality_plot_df(m, days)
seas <- predict_seasonal_components(m, df.y)
seas$ds <- df.y$ds
gg.yearly <- ggplot2::ggplot(seas, ggplot2::aes(x = ds, y = yearly,
group = 1)) +
ggplot2::geom_line(color = "#0072B2", na.rm = TRUE) +
ggplot2::labs(x = "Day of year") +
ggplot2::scale_x_datetime(labels = scales::date_format('%B %d'))
if (uncertainty) {
gg.yearly <- gg.yearly +
ggplot2::geom_ribbon(ggplot2::aes(ymin = yearly_lower,
ymax = yearly_upper),
alpha = 0.2,
fill = "#0072B2",
na.rm = TRUE)
}
return(gg.yearly)
}
#' Plot a custom seasonal component.
#'
#' @param m Prophet model object.
#' @param name String name of the seasonality.
#' @param uncertainty Boolean to plot uncertainty intervals.
#'
#' @return A ggplot2 plot.
#'
#' @keywords internal
plot_seasonality <- function(m, name, uncertainty = TRUE) {
# Compute seasonality from Jan 1 through a single period.
start <- set_date('2017-01-01')
period <- m$seasonalities[[name]]$period
end <- start + period * 24 * 3600
plot.points <- 200
days <- seq(from=start, to=end, length.out=plot.points)
df.y <- seasonality_plot_df(m, days)
seas <- predict_seasonal_components(m, df.y)
seas$ds <- df.y$ds
gg.s <- ggplot2::ggplot(
seas, ggplot2::aes_string(x = 'ds', y = name, group = 1)) +
ggplot2::geom_line(color = "#0072B2", na.rm = TRUE)
if (period <= 2) {
fmt.str <- '%T'
} else if (period < 14) {
fmt.str <- '%m/%d %R'
} else {
fmt.str <- '%m/%d'
}
gg.s <- gg.s +
ggplot2::scale_x_datetime(labels = scales::date_format(fmt.str))
if (uncertainty) {
gg.s <- gg.s +
ggplot2::geom_ribbon(
ggplot2::aes_string(
ymin = paste0(name, '_lower'), ymax = paste0(name, '_upper')
),
alpha = 0.2,
fill = "#0072B2",
na.rm = TRUE)
}
return(gg.s)
}
#' Plot the prophet forecast.
#'
#' @param x Prophet object.
#' @param fcst Data frame returned by predict(m, df).
#' @param uncertainty Boolean indicating if the uncertainty interval for yhat
#' should be plotted. Must be present in fcst as yhat_lower and yhat_upper.
#' @param ... additional arguments
#' @importFrom dplyr "%>%"
#' @return A dygraph plot.
#'
#' @examples
#' \dontrun{
#' history <- data.frame(ds = seq(as.Date('2015-01-01'), as.Date('2016-01-01'), by = 'd'),
#' y = sin(1:366/200) + rnorm(366)/10)
#' m <- prophet(history)
#' future <- make_future_dataframe(m, periods = 365)
#' forecast <- predict(m, future)
#' dyplot.prophet(m, forecast)
#' }
#'
#' @export
dyplot.prophet <- function(x, fcst, uncertainty=TRUE,
...)
{
forecast.label='Predicted'
actual.label='Actual'
# create data.frame for plotting
df <- df_for_plotting(x, fcst)
# build variables to include, or not, the uncertainty data
if(uncertainty && exists("yhat_lower", where = df))
{
colsToKeep <- c('y', 'yhat', 'yhat_lower', 'yhat_upper')
forecastCols <- c('yhat_lower', 'yhat', 'yhat_upper')
} else
{
colsToKeep <- c('y', 'yhat')
forecastCols <- c('yhat')
}
# convert to xts for easier date handling by dygraph
dfTS <- xts::xts(df %>% dplyr::select_(.dots=colsToKeep), order.by = df$ds)
# base plot
dyBase <- dygraphs::dygraph(dfTS)
presAnnotation <- function(dygraph, x, text) {
dygraph %>%
dygraphs::dyAnnotation(x, text, text, attachAtBottom = TRUE)
}
dyBase <- dyBase %>%
dygraphs::dyOptions(colors = RColorBrewer::brewer.pal(3, "Set1")) %>%
# plot actual values
dygraphs::dySeries('y', label=actual.label) %>%
# plot forecast and ribbon
dygraphs::dySeries(forecastCols, label=forecast.label) %>%
# allow zooming
dygraphs::dyRangeSelector() %>%
# make unzoom button
dygraphs::dyUnzoom()
if (!is.null(x$holidays)) {
for (i in 1:nrow(x$holidays)) {
# make a gray line
dyBase <- dyBase %>% dygraphs::dyEvent(x$holidays$ds[i],color = "rgb(200,200,200)", strokePattern = "solid")
dyBase <- dyBase %>% dygraphs::dyAnnotation(x$holidays$ds[i], x$holidays$holiday[i], x$holidays$holiday[i], attachAtBottom = TRUE)
}
}
return(dyBase)
}