Meer vapply()

Het verschil tussen vapply() en sapply() werd in het vorige voorbeeld getoond om aan te geven dat vapply() terecht kan falen, maar wat als het niet faalt? Als er geen fouten zijn, geeft vapply() een vereenvoudigd resultaat terug op basis van het argument FUN.VALUE.

De stock_return-gegevensset met dagelijkse rendementen voor Apple, IBM en Microsoft is beschikbaar. De functie sharpe() is ook beschikbaar.

Deze oefening maakt deel uit van de cursus

R voor finance voor gevorderden

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Oefeninstructies

Bereken de sharpe-ratio voor elk aandeel met vapply().
Gebruik summary() op de kolom apple om een 6-getallen-samenvatting te krijgen.
Pas vapply() met de functie summary() toe over stock_return om elke kolom samen te vatten.

Praktische interactieve oefening

Probeer deze oefening eens door deze voorbeeldcode in te vullen.

# Sharpe ratio for all stocks
vapply(___, ___, FUN.VALUE = numeric(___))

# Summarize Apple
___

# Summarize all stocks
vapply(___, ___, FUN.VALUE = numeric(___))

Code bewerken en uitvoeren

Deze oefening maakt deel uit van de cursus

R voor finance voor gevorderden

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Exercise 1: Repeat loops Exercise 2: Repeat, repeat, repeat Exercise 3: When to break?Exercise 4: While loops Exercise 5: While with a print Exercise 6: While with a plot Exercise 7: Break it Exercise 8: For loops Exercise 9: Loop over a vector Exercise 10: Loop over data frame rows Exercise 11: Loop over matrix elements Exercise 12: Break and next

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Huidige oefening

Exercise 11: Anonieme functies Exercise 12: Gefeliciteerd