Plot number of change points depending on q

Plots number of change points given different values of q

plot_n_cp_by_q(data, id_col, ...)

Arguments

data

generated by calculate_n_cp_by_q

id_col

column name of the track id column

...

other arguments used in tinyplot

Examples

library(tinyplot)
data("cpttestdata")
data <- trackframe::as.trackframe(cpttestdata, crs = NA)

calculate_n_cp_by_q <- function(tf, q=seq_len(10), alpha = 0.01) {
 if(length(attr(tf, 'id'))!=1) stop('only implemented for 1 id col')
 do.call(rbind, lapply(seq_len(10), function(q) {
   cp <- change_point_test(
       tf,
       alpha = alpha,
       q = q
 )
 df <- as.data.frame(rowsum(as.integer(cp$cp_id != 0), as.factor(cp[,attr(tf, 'id')])))
 names(df) <- 'n_cp'
 df$track_id <- rownames(df)
 rownames(df) <- NULL
   df$q <- q
   df
 }))
}

n_cp_by_q <- calculate_n_cp_by_q(data)
tinytheme("clean2")
plot_n_cp_by_q(data = n_cp_by_q, id_col = "track_id")