R/C2/Aesthetic-Mapping-in-ggplot2/English-timed

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Time Narration
00:01 Welcome to this tutorial on Aesthetic Mapping in ggplot2.
00:06 In this tutorial, we will learn,
00:10 What is aesthetic
00:12 How to create plots using aesthetic
00:16 Tuning parameters in aesthetic
00:20 To understand this tutorial, you should know,
00:24 Basics of statistics
00:27 Basics of ggplot2 package
00:30 Data frames
00:33 If not, please locate the relevant tutorials on R on this website.
00:40 This tutorial is recorded on
00:43 Ubuntu Linux OS version 16.04
00:48 R version 3.4.4
00:52 RStudio version 1.1.463
00:57 Install R version 3.2.0 or higher.
01:03 For this tutorial, we will use
01:06 A data frame moviesData.csv, and
01:10 A script file aesPlots.R.
01:16 Please download these files from the Code files link of this tutorial.
01:23 I have downloaded and moved these files to aesPlots folder.
01:30 This folder is located in myProject folder on my Desktop.
01:36 I have set aesPlots folder as my Working Directory.
01:42 Now let us see what is Aesthetic?
01:46 Aesthetic is a visual property of the objects in a plot.
01:50 It includes lines, points, symbols, colors, and position.
01:57 It is used to add customization to our plots.
02:01 Let us switch to RStudio.
02:05 Open the script aesPlots.R in RStudio.
02:11 Here, we are plotting a scatter plot between critics_score and audience_score of movies.
02:19 Run this script by clicking on the Source button.
02:24 Scatter plot appears in the Plots window.
02:28 movies data frame opens in the Source window.
02:33 In this scatter plot, each point refers to a particular movie.
02:39 Suppose we want to color these points according to the genre of the movies.
02:45 In the Source window, scroll from left to right.
02:49 As we can see that there are different genres like
02:54 Drama
02:56 Comedy
02:58 Horror
03:00 Documentary, etc.
03:03 So, we will assign a unique color to each genre.
03:08 Click on the script aesPlots.R
03:12 In the Source window, type the following commands.
03:18 Inside aes, we have added color argument and set it to genre.
03:26 Save the script and run the current line by pressing Ctrl+ Enter keys simultaneously.
03:36 Modified scatter plot appears in the Plots window.
03:41 In the Plots window, click on the Zoom button to maximize the plot.
03:47 We can see that each point is assigned a unique color according to its genre.
03:54 In the right side of the plot, we can view the mapping of genres with their colors.
04:01 Close this plot.
04:03 Now, we will learn how to draw a bar chart using ggplot function.
04:09 In the Source window, click on movies.
04:13 In the Source window, scroll from left to right.
04:17 Let us inspect the object named mpaa underscore rating in movies.
04:26 Click on the script aesPlots.R
04:31 In the Source window, type the following commands.
04:36 Run the last two lines of code.
04:40 mpaa_rating is a factor.
04:45 It has 6 levels like
04:47 G NC-17 PG PG-13 R, and Unrated.
04:55 So, our bar chart will have 6 different bars.
05:00 Each bar will represent the number of movies in each level.
05:06 In the Source window, type the following command.
05:11 Here, we have mapped mpaa underscore rating on X-axis.
05:18 Next, we have used geom underscore bar as we are plotting a bar chart.
05:25 Similarly, we can use
05:27 geom_line to draw a line chart
05:31 geom_boxplot to draw a box plot
05:36 Run the current line.
05:39 The bar chart appears in the Plots window.
05:43 Now, we will learn how to add labels to this bar chart.
05:49 In the Source window, after geom_bar(), type space plus sign and press Enter.
05:58 Now type the following commands.
06:02 Here, we have used labs argument to add label and title to the bar chart.
06:09 Run the current line.
06:12 The modified bar chart appears in the Plots window.
06:17 We can see that most of the movies have been rated as R in mpaa_rating.
06:26 Suppose, in this bar chart, we want to view the distribution of movies by genre.
06:33 In the Source window, type the following command.
06:37 Inside aes, we have added fill argument and set it to genre.
06:44 Run the current line.
06:47 The modified bar chart appears in the Plots window.
06:52 In the Plots window, click on the Zoom button to maximize the plot.
06:58 There are seven different colors in each bar.
07:03 Besides the plot, the meaning of each color has been given.
07:09 Close the plot.
07:12 In the Source window, click on movies data frame.
07:17 Now we will plot a histogram for the object named as runtime in movies.
07:25 Recall that, we have already learned how to plot a histogram using hist function.
07:32 Now we will use ggplot2 package to plot a histogram.
07:38 Click on the script aesPlots.R
07:43 In the Source window, type the following command.
07:48 Save the script and run the current line.
07:53 There are some warning messages, which we will ignore for now.
07:58 The histogram appears in the Plots window.
08:02 Let us summarize what we have learnt.
08:06 In this tutorial, we have learnt,
08:09 What is aesthetic
08:11 How to create plots using aesthetic
08:15 Tuning parameters in aesthetic
08:19 We now suggest an assignment.
08:22 Using built-in data set mtcars, draw a bar chart from the object cyl.
08:30 Add suitable labels to this bar chart.
08:34 The video at the following link summarises the Spoken Tutorial project.
08:39 Please download and watch it.
08:42 We conduct workshops using Spoken Tutorials and give certificates.
08:47 Please contact us.
08:49 Please post your timed queries in this forum.
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08:57 The FOSSEE team coordinates the TBC project.
09:01 For more details, please visit these sites.
09:05 The Spoken Tutorial project is funded by MHRD, Govt. of India
09:12 The script for this tutorial was contributed by Varshit Dubey (CoE Pune).
09:19 This is Sudhakar Kumar from IIT Bombay signing off. Thanks for watching.

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