Meritshot Tutorials
R Tutorial
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R-OverviewR-Overview
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R Basic SyntaxR Basic Syntax
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R Data TypesR Data Types
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R-Data StructuresR-Data Structures
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R-VariablesR-Variables
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R-OperatorsR-Operators
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R-StringsR-Strings
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R-FunctionR-Function
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R-ParametersR-Parameters
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Arguments in R programmingArguments in R programming
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R String MethodsR String Methods
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R-Regular ExpressionsR-Regular Expressions
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Loops in R-programmingLoops in R-programming
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R-CSV FILESR-CSV FILES
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Statistics in-RStatistics in-R
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Probability in RProbability in R
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Confidence Interval in RConfidence Interval in R
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Hypothesis Testing in RHypothesis Testing in R
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Correlation and Covariance in RCorrelation and Covariance in R
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Probability Plots and Diagnostics in RProbability Plots and Diagnostics in R
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Error Matrices in RError Matrices in R
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Curves in R-Programming LanguageCurves in R-Programming Language
R-Parameters
In R, function parameters (or arguments) play a central role in determining how functions are called and executed. Here’s a deeper look at different aspects of R parameters, including default parameters, ellipsis (…), lazy evaluation, and argument matching.
1. Passing Parameters by Name
When passing parameters by name, you explicitly specify the argument names in the function call. This way, the order of arguments doesn’t matter, as they are matched based on the name.
# Example function
calculate_area <- function(length, width) { return(length * width)
}
# Passing arguments by name
result <- calculate_area(length = 5, width = 10)
print(result)
# Output: 50
Benefits:
- Readability: It’s clear what each argument
- Flexibility: Order of arguments can be
2. Passing Parameters by Position
When passing parameters by position, the values are assigned to the arguments based on the order in which they are passed. You don’t specify the argument names.
# Example function
calculate_area <- function(length, width) {
return(length * width)
}
# Passing arguments by position
result <- calculate_area(5, 10)
print(result) # Output: 50
Benefits:
- Concise: Fewer characters are needed in the function
- Useful for functions with fewer
Caution:
- Order-sensitive: Arguments must be passed in the exact order expected by the
3. Using Both Position and Names for Parameters
You can mix both approaches, passing some arguments by position and others by name. R matches positional arguments first, and then matches the named arguments.
# Example function
calculate_area <- function(length, width, unit = “square meters”) {
print(paste(“The area is”, length * width, unit))
}
# Mixing position and named arguments
calculate_area(5, width = 10) # Output: “The area is 50 square meters”
Benefits:
- Flexible: You can pass important or more commonly used arguments by position while specifying less frequently used or optional ones by
- Reduces potential errors: You only need to be cautious with positional arguments, and named ones provide
Summary
- By Name: More readable and
- By Position: Concise but order-sensitive.
- Both: Provides a balance between conciseness and
