Comece agoraComece grátis

Cognostics from nested data frames

Let's compute the average close price, average volume, and annual return as cognostics. The variables that these are based on, open, close, and volume, are inside the nested data frame data in our by_symbol dataset.

Note that a function, annual_return(), has been provided for convenience.

Este exercicio faz parte do curso

Visualizing Big Data with Trelliscope in R

Ver curso

Instruções do exercicio

  • Use map() to compute over every nested data frame of data.
  • Inside the map function, create a summary data frame containing the average close price, the average volume, and the annual percentage return. Take a look at by_symbol$data[[1]] to recall the column names that are available.

exercicio interativo prático

Tente este exercicio completando este código de exemplo.

library(trelliscopejs)
library(dplyr)
library(purrr)

annual_return <- function(x)
  100 * (tail(x$close, 1) - head(x$open, 1)) / head(x$open, 1)

# Compute by_symbol_avg
by_symbol_avg <- mutate(by_symbol,
  stats = ___(___, function(x) {
    data_frame(
      mean_close = mean(x$___),
      mean_volume = mean(x$___),
      annual_return = annual_return(x)
    )
  }))
Editar e Executar Código