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Extract the Close column from many instruments

The previous exercise taught you how to use do.call(merge, eapply(env, fun)) to apply a function to each object in an environment and then combine all the results into one object.

Let's use what you learned to solve a very common problem. Often you will need to load similar data for many instruments, extract a column, and create one object that contains that specific column for every instrument.

Cet exercice fait partie du cours

Importing and Managing Financial Data in R

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Instructions

  • Use new.env() to create a new environment named data_env.
  • Use getSymbols() to load data into data_env by using the env argument.
  • Finish the commands that have been started for you. Fill in the blanks with the appropriate functions.
  • View the first few rows of close_data.

Exercice interactif pratique

Essayez cet exercice en complétant cet exemple de code.

# Symbols
symbols <- c("AAPL", "MSFT", "IBM")

# Create new environment


# Load symbols into data_env


# Extract the close column from each object and combine into one xts object
close_data <- ___(merge, ___(data_env, Cl))

# View the head of close_data
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