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All together now!

Great! You have learned a lot about operators and subsetting. This will serve you well in future data analysis projects. Let's do one last exercise that combines a number of operators together.

A new version of the stocks data frame is available for you to use.

Este exercício faz parte do curso

Intermediate R for Finance

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Instruções do exercício

  • First, print stocks. It contains Apple and Microsoft prices for December, 2016.
  • It seems like you have missing data. Let's investigate further. Use weekdays() on the date column, and assign it to stocks as the column, weekday.
  • View stocks now. The missing data is on weekends! This makes sense, the stock market is not open on weekends.
  • Remove the missing rows using subset(). Use!is.na() on apple as your condition. Assign this new data frame to stocks_no_NA.
  • Now, you are interested in days where apple was above 117, or when micr was above 63. Use relational operators, |, and subset() to accomplish this with stocks_no_NA.

Exercício interativo prático

Experimente este exercício completando este código de exemplo.

# View stocks
___

# Weekday investigation
stocks$weekday <- 

# View stocks again
___

# Remove missing data
stocks_no_NA <- ___

# Apple and Microsoft joint range
___
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