R：在ggplot2中使用条形图中的日期

Question

I would like to create a bar plot that displays the number of Date entries for a certain date in the y axis of a bar graph and the date on the x axis of a graph. At the same time, I would like to split the bar into a Yes and No section.

Date,Hungry
Friday, March 24, 2017 2:33:46 PM,Yes
Friday, March 24, 2017 3:39:46 PM,No
Friday, March 24, 2017 4:39:46 PM,Yes
Friday, March 24, 2017 5:39:46 PM,No
Friday, March 24, 2017 6:39:46 PM,Yes
Friday, March 24, 2017 7:39:46 PM,Yes
Saturday, March 25, 2017 9:41:00 AM,Yes
Saturday, March 25, 2017 10:41:00 AM,Yes
Saturday, March 25, 2017 11:41:00 AM,No
Saturday, March 25, 2017 13:41:00 AM,No
Saturday, March 25, 2017 14:41:00 AM,No
Saturday, March 25, 2017 15:41:00 AM,Yes
Saturday, March 25, 2017 16:41:00 AM,Yes

In total, there are 6 Date entries on the 25 of March (3Yes/3No) and 7 Date entries on the 26 of March (4Yes/3No). Resulting in a graph like this:

Hungry
 ^
 |
 |
 |
 |
9|
 |              _
 |   _         |n|
 |  |n|        |o|
5|  |o|        |_|
 |  |_|        |y|
 |  |y|        |e|
 |  |e|        |s|
1|__|s|________|_|__________>
                            Date

     2          2            
     4          5            
     M          M            
     A          A
     R          R
     C          C
     H          H

Sorry for asking this seemingly simple question.

EDIT. Adam Quek ask me to provide some data with dput . Here are a few rows:

dat <- structure(list(Date = structure(1:4, .Label = c("Friday, March 24, 2017 4:39:46 PM", 
"Friday, March 24, 2017 7:21:33 PM", "Friday, March 24, 2017 7:21:51 PM", 
"Friday, March 24, 2017 7:22:00 PM", "Friday, March 24, 2017 7:22:14 PM", 
"Saturday, March 25, 2017 8:00:10 AM", "Saturday, March 25, 2017 8:00:25 AM", 
"Saturday, March 25, 2017 8:00:46 AM", "Saturday, March 25, 2017 8:01:02 AM", 
"Saturday, March 25, 2017 8:01:20 AM", "Saturday, March 25, 2017 8:01:37 AM", 
"Saturday, March 25, 2017 8:01:50 AM"), class = "factor"), Hungry = structure(c(2L, 
1L, 2L, 1L), .Label = c("No", "Yes"), class = "factor")), .Names = c("Date", 
"Hungry"), row.names = c(NA, 4L), class = "data.frame")

Answer 1

Here's a quick way to plot what you need.

library(ggplot2)
ggplot(dat, aes(date, fill=as.factor(hungry))) + 
      geom_bar()

I remade the data as:

dat <- structure(list(date = structure(c(17249, 17249, 17249, 17249, 
17249, 17249, 17250, 17250, 17250, 17250, 17250, 17250, 17250
), class = "Date"), hungry = structure(c(2L, 1L, 2L, 1L, 2L, 
2L, 2L, 2L, 1L, 1L, 1L, 2L, 2L), .Label = c("No", "Yes"), class = "factor")), class = "data.frame", .Names = c("date", 
"hungry"), row.names = c(NA, -13L))

EDIT:

Additional input with the new example data:

(i) Change the Date into a readable date format in R. Check out R helpfile for strptime on the date/time format

dat$date <- as.Date(dat$Date, "%A, %B %d, %Y %X")

(ii) plot with similar ggplot as above.

ggplot(dat, aes(date, fill=Hungry)) + 
      geom_bar()