R Language
- Getting started with R Language
- Awesome Book
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- Awesome Course
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- *apply family of functions (functionals)
- .Rprofile
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- Analyze tweets with R
- ANOVA
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- Bibliography in RMD
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- data.table
- Date and Time
- Date-time classes (POSIXct and POSIXlt)
- Debugging
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- dplyr
- Expression: parse + eval
- Extracting and Listing Files in Compressed Archives
- Factors
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- Feature Selection in R -- Removing Extraneous Features
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- Implement State Machine Pattern using S4 Class
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- Introduction to Geographical Maps
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- Meta: Documentation Guidelines
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- Network analysis with the igraph package
- Non-standard evaluation and standard evaluation
- Numeric classes and storage modes
- Object-Oriented Programming in R
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- Performing a Permutation Test
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- Probability Distributions with R
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- Recycling
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- Reshaping data between long and wide forms
- RESTful R Services
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- RODBC
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- Run-length encoding
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- Solving ODEs in R
- Spark API (SparkR)
- spatial analysis
- Speeding up tough-to-vectorize code
- Split function
- sqldf
- Standardize analyses by writing standalone R scripts
- String manipulation with stringi package
- strsplit function
- Subsetting
- Survival analysis
- Text mining
- The character class
- The Date class
- The logical class
- tidyverse
- Time Series and Forecasting
- Updating R and the package library
- Updating R version
- Using pipe assignment in your own package %<>%: How to ?
- Using texreg to export models in a paper-ready way
- Variables
- Web Crawling in R
- Web scraping and parsing
- Writing functions in R
- xgboost
R Language The Date class
Remarks
Related topics
Jumbled notes
Date: Stores time as number of days since UNIX epoch on1970-01-01. with negative values for earlier dates.- It is represented as an integer (however, it is not enforced in the internal representation)
- They are always printed following the rules of the current Gregorian calendar, even though the calendar was not in use a long time ago.
- It doesn't keep track of timezones, so it should not be used to truncate the time out of
POSIXctorPOSIXltobjects. sys.Date()returns an object of classDate
More notes
- lubridate's
ymd,mdy, etc. are alternatives toas.Datethat also parse to Date class; see Parsing dates and datetimes from strings with lubridate. - data.table's experimental IDate class is derived from and is mostly interchangeable with Date, but is stored as integer instead of double.
