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Setting effects codes

In this exercise, we will change the chocolate data frame so that the contrasts for the factors Brand and Type are set to effects codes. The chocolate data is already loaded and I've written the code to change the Brand factor. Your job is to copy that code and modify it for the Type variable.

Deze oefening maakt deel uit van de cursus

Choice Modeling for Marketing in R

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Oefeninstructies

  • Copy the three lines of code I've written to change the contrasts for the Brand variable.
  • Change chocolate$Brand to chocolate$Type in the copied code.

Praktische interactieve oefening

Probeer deze oefening eens door deze voorbeeldcode in te vullen.

# set the contrasts for Brand to effects code
contrasts(chocolate$Brand) <- contr.sum(levels(chocolate$Brand))
dimnames(contrasts(chocolate$Brand))[[2]] <- levels(chocolate$Brand)[1:4]
contrasts(chocolate$Brand)

# set the contrasts for Type to effects code
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