Incorrect use of dietaryindex function

[jamesjiadazhan]

In R, the data users put in the arguments (or parameters) will fill in the default locations for the function, if you do not specify them. This may result in errors.

For example, for the following function:

MED_NHANES_FPED(
      FPED_PATH = NHANES_20172018$FPED,
      NUTRIENT_PATH = NHANES_20172018$NUTRIENT,
      DEMO_PATH = NHANES_20172018$DEMO,
      FPED_PATH2 = NHANES_20172018$FPED2,
      NUTRIENT_PATH2 = NHANES_20172018$NUTRIENT2
)

The example filled FPED_PATH2 and NUTRIENT_PATH2 as the first and second argument, so the function will assume what you put are FPED_PATH and NUTRIENT_PATH.

• This results the function to prompt the error because this is an incorrect use of the data

The correct use is this if user is only interested in the second day data:

MED_NHANES_FPED(
      DEMO_PATH = NHANES_20172018$DEMO,
      FPED_PATH2 = NHANES_20172018$FPED2,
      NUTRIENT_PATH2 = NHANES_20172018$NUTRIENT2
)

In the future, if users are not absolutely familiar with the function, they should specify which parameters they want to pass their data input.

• In fact, this practice is very helpful in R, because in many cases, if you have the data input in the wrong places, it will still generate the wrong data output, so this is a standard "garbage in, garbage out" scenario.