Course
Data Frames
Convert a List to a DataframeCreate an Empty DataframeCombine Two Dataframe into OneChange Column Name of a DataframeExtract Columns From a DataframeDrop Columns in a DataframeReorder Columns in a DataframeSplit DataframeMerge Multiple DataframesDelete Rows From DataframeMake a List of DataframesIntroduction
"Hello World" ProgramAdd Two VectorsFind Sum, Mean and Product of Vector in R ProgrammingTake Input From UserGenerate Random Number from Standard DistributionsSample from a PopulationFind Minimum and MaximumSort a VectorStrings
Concatenate Two StringsFind the Length of a StringCheck if Characters are Present in a StringExtract n Characters From a StringReplace Characters in a StringCompare two StringsConvert Factors to CharactersTrim Leading and Trailing WhitespacesVectors
Concatenate a Vector of StringsCheck if a Vector Contains the Given ElementCount the Number of Elements in a VectorFind Index of an Element in a VectorAccess Values in a VectorAdd Leading Zeros to VectorR Program to Check if a Number is Positive, Negative or Zero
Example: Check Positive, Negative or Zero
# In this program, we input a number
# check if the number is positive or
# negative or zero and display
# an appropriate message
num = as.double(readline(prompt="Enter a number: "))
if(num > 0) {
print("Positive number")
} else {
if(num == 0) {
print("Zero")
} else {
print("Negative number")
}
}
Output 1
Enter a number: -9.6
[1] "Negative number"
Output 2
Enter a number: 2
[1] "Positive number"
A number is positive if it is greater than zero.
We check this in the expression of if
. If it is FALSE
, the number will either be zero or negative.
This is also tested in subsequent expression.