Python/C2/Other-types-of-plots/English-timed

Visual Cue	Narration
0:01	Hello Friends and welcome to the tutorial on Other types of plots.
0:06	Till now we have seen only one kind of plotting.
0:10	Hence in this tutorial we will be looking at some more kinds of plots.
0:16	At the end of this tutorial, you will be able to Create scatter plot Create pie charts Create bar charts Create log-log plots Use the matplotlib help
0:29	So let us begin with scatter plot
0:33	Before beginning this tutorial,we would suggest you to complete the tutorial on "Loading data from files" and "Plotting data".
0:42	In a scatter plot, the data is displayed as a collection of points, where each point determines it's position on the horizontal axis and the vertical axis respectively.
0:54	This kind of plot is also called a scatter chart, a scatter diagram or a scatter graph.
1:01	Before we start with the topic, let us start our IPython interpreter
1:06	So type ipython hypen pylab
1:13	Plot a scatter plot showing the percentage profit of a company A from the year 2000-2010.
1:22	The data for the same is available in the file company-a-data.txt.
1:33	Type cat space slash home slash fossee bacslash other-plot slash company-a-data.txt (enter)
1:50	The data file has two lines with a set of values in each line, the first line representing years and the second line representing the profit percentages.
2:02	To produce the scatter plot, we first need to load the data from the file using loadtxt command.
2:10	Type year,profit = loadtxt within bracket in single quote slash home slash fossee slash other-plot slash company-a-data.txt comma dtype=type in bracket int() hit enter
2:52	By default loadtxt converts the value to float.
2:57	The dtype=type within bracket int() argument in loadtxt converts the value to integer, as we require the data as integer further in the tutorial.
3:11	Now in-order to generate the scatter graph we will use the function scatter()
3:18	Type scatter within bracket year comma profit and hit enter
3:32	Notice that we passed two arguments to scatter() function, first one the values in x-coordinate, year, and the other the values in y-coordinate, the profit percentage.
3:57	Plot a scatter plot of the same data in company-a-data.txt with red diamond markers.
4:09	Pause the video here, try out the following exercise and resume the video.
4:17	Now let us see another kind of plot, the pie chart, for the same data.
4:40	A pie chart or a circle graph is a circular chart divided into sectors, illustrating proportion.
4:49	Plot a pie chart representing the profit percentage of company A, with the same data from file company-a-data.txt.
5:00	So let us reuse the data we have loaded from the file previously.
5:11	We can plot the pie chart using the function pie().
5:15	Type pie within bracket profit comma labels=year
5:29	Notice that we passed two arguments to the function pie().
5:33	First one the values and the next one the set of labels to be used in the pie chart.
5:38	Plot a pie chart with the same data with colors for each wedges as white, red, black, magenta,yellow, blue, green, cyan, yellow, magenta and blue respectively.
5:58	Pause the video here, try out the following exercise and resume the video.
6:05	Now let us move on to the bar charts.
6:08	A bar chart or bar graph is a chart with rectangular bars with lengths proportional to the values that they represent.
6:19	Plot a bar chart representing the profit percentage of company A, with the same data from file company-a-data.txt.
6:30	So let us reuse the data we have loaded from the file previously.
6:34	We can plot the bar chart using the function bar()
6:44	type bar within bracket year comma profit
6:52	Note that the function bar() needs at least two arguments one the values in x-coordinate and the other values in y-coordinate which is used to determine the height of the bars.
7:05	Plot a bar chart which is not filled and which is hatched with 45o slanting lines as shown in the image.
7:17	The data for the chart may be obtained from the file company-a-data.txt.
7:26	Type bar within bracket year comma profit comma fill=False comma hatch=slash in single quote hit enter
8:05	Now let us move on to the log-log plot.
8:10	A log-log graph or a log-log plot is a two-dimensional graph of numerical data that uses logarithmic scales on both the horizontal and vertical axes.
8:24	Because of the nonlinear scaling of the axes, a function of the form y = axb will appear as a straight line on a log-log graph
8:38	Plot a log-log chart of y=5 into x3 for x from 1-20.
8:49	Before we actually plot let us calculate the points needed for that.
8:54	x = linspace within brackets 1 comma 20 comma 100 y = 5 into x into into 3
9:23	Here is the syntax of the log-log function.
9:28	Now we can plot the log-log chart using loglog() function,
9:34	Type loglog within brackets x comma y hit enter
9:48	To understand the difference between a normal plot and a log-log plot let us create another plot using the function plot.
9:57	figure within brackets 2 plot within brackets x comma y
10:24	The difference is clear.So that was log-log() plot.
10:33	Now we will see few more plots and also see how to access help of matplotlib over the Internet.
10:43	Help about matplotlib can be obtained from matplotlib.sourceforge.net/contents.html
10:55	More plots can be seen at matplotlib.sourceforge.net slash users slash screenshots.html and also at matplotlib.sourceforge.net slash gallery.html
11:13	This brings us to the end of this tutorial. In this tutorial we learnt to,
11:20	1. Plot a scatter plot using scatter() function
11:22	2. Plot a pie chart using pie() function
11:25	3. Plot a bar chart using bar() function
11:28	4. Plot a log-log graph using loglog() function
11:33	5. Access the matplotlib online help.Thank you.
11:42	Here are some self assessment questions for you to solve.
11:46	1. scatter within bracket x comma y comma color=blue in single quotes comma marker= in single quotesd< slash tt> and <tt>plot within bracket x comma y comma color=b in single quotes comma marker=in single quotes d) does exactly the same.
12:04	Is True or False?
12:07	. What statement can be issued to generate a bar chart with vertical line hatching.
12:15	bar within bracket x comma y comma color=w in single quote comma hatch=in single quote slash
12:27	bar within bracket x comma y comma fill=False comma hatch=slash slash in single quote
12:38	bar within bracket x comma y comma fill=False comma hatch=in single quote|)
12:52	bar within bracket x comma y comma color= in single quote w comma hatch=single quote
13:02	And the answers,
13:06	1. False.
13:9	Both functions do not produce the same kind of plot.
13:13	2. bar within bracket x comma y comma fill=False comma hatch=in single quote|) is the correct option to generate a bar chart with vertical line hatching.
13:31	Hope you have enjoyed this tutorial and found it useful.
13:34	Thank you!

Contributors and Content Editors

Gaurav, Jyotisolanki, Minal, PoojaMoolya, Ranjana, Sneha