diff --git a/02_RProgramming/Dates/index.Rmd b/02_RProgramming/Dates/index.Rmd index 52462db80..d435714c4 100644 --- a/02_RProgramming/Dates/index.Rmd +++ b/02_RProgramming/Dates/index.Rmd @@ -8,7 +8,7 @@ framework : io2012 # {io2012, html5slides, shower, dzslides, ...} highlighter : highlight.js # {highlight.js, prettify, highlight} hitheme : tomorrow # url: - lib: ../../libraries + lib: ../../librariesNew assets: ../../assets widgets : [mathjax] # {mathjax, quiz, bootstrap} mode : selfcontained # {standalone, draft} @@ -95,13 +95,11 @@ p$sec Finally, there is the `strptime` function in case your dates are written in a different format -```r +```{r} datestring <- c("January 10, 2012 10:40", "December 9, 2011 9:10") x <- strptime(datestring, "%B %d, %Y %H:%M") x -## [1] "2012-01-10 10:40:00" "2011-12-09 09:10:00" class(x) -## [1] "POSIXlt" "POSIXt" ``` I can _never_ remember the formatting strings. Check `?strptime` for details. diff --git a/02_RProgramming/Dates/index.html b/02_RProgramming/Dates/index.html index b0fe8124f..c3d93923d 100644 --- a/02_RProgramming/Dates/index.html +++ b/02_RProgramming/Dates/index.html @@ -8,51 +8,46 @@ - - + - - - - + + - - - - - - - + - + + +
+

Dates and Times in R

+

+

Roger D. Peng, Associate Professor of Biostatistics
Johns Hopkins Bloomberg School of Public Health

+
+
+ - - - - -
-

Dates and Times in R

-

-

Roger D. Peng, Associate Professor of Biostatistics
Johns Hopkins Bloomberg School of Public Health

-
- - - +

Dates and Times in R

-
+

R has developed a special representation of dates and times

    @@ -66,11 +61,11 @@

    Dates and Times in R

    - +

    Dates in R

    -
    +

    Dates are represented by the Date class and can be coerced from a character string using the as.Date() function.

    x <- as.Date("1970-01-01")
@@ -86,11 +81,11 @@ 
    Dates in R
    
   
 
 
-      
+
   
    
     
    Times in R
    
   
    
-  
    
+  
    
     
    Times are represented using the POSIXct or the POSIXlt class
    
 
 
      
@@ -110,11 +105,11 @@ 
      Times in R
      
   
 
 
-      
+
   
      
     
      Times in R
      
   
      
-  
      
+  
      
     
      Times can be coerced from a character string using the as.POSIXlt or as.POSIXct function.
      
 
 
      x <- Sys.time()
@@ -132,11 +127,11 @@ 
      Times in R
      
   
 
 
-      
+
   
      
     
      Times in R
      
   
      
-  
      
+  
      
     
      You can also use the POSIXct format.
      
 
 
      x <- Sys.time()
@@ -155,19 +150,26 @@ 
      Times in R
      
   
 
 
-      
+
   
      
     
      Times in R
      
   
      
-  
      
-    
      Finally, there is the strptime function in case your dates are written in a different format
      
+  
      
+    
      Finally, there is the strptime function in case your dates are
+written in a different format
      
 
-
      datestring <- c("January 10, 2012 10:40", "December 9, 2011
+
      datestring <- c("January 10, 2012 10:40", "December 9, 2011 9:10")
 x <- strptime(datestring, "%B %d, %Y %H:%M")
 x
-## [1] "2012-01-10 10:40:00" "2011-12-09 09:10:00"
-class(x)
-## [1] "POSIXlt" "POSIXt"
+
      
+
+
      ## [1] "2012-01-10 10:40:00 EST" "2011-12-09 09:10:00 EST"
+
      
+
+
      class(x)
+
      
+
+
      ## [1] "POSIXlt" "POSIXt"
 
      
 
 
      I can never remember the formatting strings. Check ?strptime for details.
      
@@ -176,11 +178,11 @@ 
      Times in R
      
   
 
 
-      
+
   
      
     
      Operations on Dates and Times
      
   
      
-  
      
+  
      
     
      You can use mathematical operations on dates and times. Well, really just + and -. You can do comparisons too (i.e. ==, <=)
      
 
 
      x <- as.Date("2012-01-01")
@@ -198,11 +200,11 @@ 
      Operations on Dates and Times
      
   
 
 
-      
+
   
      
     
      Operations on Dates and Times
      
   
      
-  
      
+  
      
     
      Even keeps track of leap years, leap seconds, daylight savings, and time zones.
      
 
 
      x <- as.Date("2012-03-01") y <- as.Date("2012-02-28") 
@@ -218,11 +220,11 @@ 
      Operations on Dates and Times
      
   
 
 
-      
+
   
      
     
      Summary
      
   
      
-  
      
+  
      
     
        
 
      • Dates and times have special classes in R that allow for numerical and statistical calculations
        • 
 
      • Dates use the Date class
        • 
@@ -236,34 +238,89 @@ 
        Summary
        
 
     
   
-
-  
 
-
-
-
-
-
-
-
-
-
+  
+  
+  
 
-
-
-
-
\ No newline at end of file
+  
+  
+  
+   
+  
\ No newline at end of file
diff --git a/02_RProgramming/Dates/index.md b/02_RProgramming/Dates/index.md
index fff705469..5e6c6789c 100644
--- a/02_RProgramming/Dates/index.md
+++ b/02_RProgramming/Dates/index.md
@@ -8,7 +8,7 @@ framework   : io2012        # {io2012, html5slides, shower, dzslides, ...}
 highlighter : highlight.js  # {highlight.js, prettify, highlight}
 hitheme     : tomorrow      # 
 url:
-  lib: ../../libraries
+  lib: ../../librariesNew
   assets: ../../assets
 widgets     : [mathjax]            # {mathjax, quiz, bootstrap}
 mode        : selfcontained # {standalone, draft}
@@ -92,14 +92,25 @@ p$sec
 
 ## Times in R
 
-Finally, there is the `strptime` function in case your dates are written in a different format
+Finally, there is the `strptime` function in case your dates are
+written in a different format
+
 
 ```r
-datestring <- c("January 10, 2012 10:40", "December 9, 2011
+datestring <- c("January 10, 2012 10:40", "December 9, 2011 9:10")
 x <- strptime(datestring, "%B %d, %Y %H:%M")
 x
-## [1] "2012-01-10 10:40:00" "2011-12-09 09:10:00"
+```
+
+```
+## [1] "2012-01-10 10:40:00 EST" "2011-12-09 09:10:00 EST"
+```
+
+```r
 class(x)
+```
+
+```
 ## [1] "POSIXlt" "POSIXt"
 ```
 I can _never_ remember the formatting strings. Check `?strptime` for details.