Python-3.4.3/C2/Plotting-Charts/English-timed
| Time | Narration |
| 00:01 | Hello friends. Welcome to the tutorial on plotting charts |
| 00:06 | At the end of this tutorial, you will be able to
Create pie charts Create bar charts and Find more information on matplotlib |
| 00:18 | To record this tutorial, I am using
Ubuntu Linux 14.04 operating system |
| 00:24 | Python 3.4.3 and IPython 5.1.0 |
| 00:31 | To practice this tutorial, you should know how to
run basic Python commands on the ipython console |
| 00:39 | Load data from files and Plot data. |
| 00:42 | If not, see the relevant Python tutorials on this website. |
| 00:47 | Let us first open the Terminal by pressing Ctrl+Alt+T keys simultaneously.
Now, type ipython3 and press Enter. |
| 00:58 | Let us initialize the pylab package.
Type %pylab and press Enter. |
| 01:06 | A pie chart is a circular chart divided into sectors, to illustrate numerical proportion |
| 01:12 | The syntax for pie() function is as follows: pie inside parentheses values comma labels equal to labels |
| 01:22 | Where values are the data to be plotted and labels – the label for each wedge in the pie chart |
| 01:30 | Plot a pie chart representing the profit percentage of company A. |
| 01:35 | Use the data from file company-a-data.txt available in the code file link of this tutorial |
| 01:43 | The data file has two columns with a set of values in each column. |
| 01:48 | The first column represents years. The second column represents the profit percentages. |
| 01:55 | To produce a scatter plot, we first need to load the data from the file using loadtxt command. |
| 02:03 | Let us clear the terminal.
Type year comma profit equal to loadtxt inside parentheses inside single quotes add the path of the file company-a-data.txt comma unpack equal to True and press Enter |
| 02:28 | unpack equal to True --> returns the transposed array of data. |
| 02:33 | Type clf open and close parentheses to clear the plot window, if any plots executed previously. |
| 02:41 | Type pie(profit comma labels equal to year) and press Enter. |
| 02:50 | Notice that we passed two arguments to the function pie(). |
| 02:55 | First one being the values, which is profit in our case. |
| 02:59 | The next one being the set of labels to be used in the pie chart, which is year in our case. |
| 03:05 | Pause the video here.
Try out the following exercise and resume the video. |
| 03:11 | Plot a pie chart with the same data with the following colors for each wedges.
white, red, black, magenta, |
| 03:19 | yellow, blue, green, cyan, |
| 03:21 | yellow, magenta and blue. |
| 03:24 | Hint: In your ipython interpreter, try typing pie question mark. |
| 03:29 | Solution to Exercise 2
Clear the plot window by typing clf open and close parentheses and press Enter. |
| 03:39 | Type pie inside parentheses profit comma labels equal to year comma colors equal to inside parentheses the color codes and press Enter. |
| 03:57 | This will display a pie chart with each wedge having the color as specified in the parameters. |
| 04:04 | A bar chart is a chart with rectangular bars
with lengths proportional to the values that they represent. |
| 04:12 | The syntax for bar chart is: bar inside parentheses x comma y
where x a sequence of data and y a sequence of data, the same length of x |
| 04:28 | Plot a bar chart representing the profit percentage of company A. |
| 04:33 | Use the data from file company-a-data.txt. |
| 04:38 | Solution to Exercise 3
Clear the plot window by typing clf open and close parentheses |
| 04:47 | Type bar open and close parentheses year comma profit and press Enter. |
| 04:56 | This will display a bar chart representing the profit percentage of company A |
| 05:02 | Plot a bar chart as shown in the image:
Hint: Bar chart is not filled and which is hatched with 45o slanting lines. |
| 05:13 | The data for the chart may be obtained from the file company-a-data.txt. |
| 05:19 | Hint: In your ipython interpreter, try typing bar question mark |
| 05:25 | Solution to Exercise 4
Clear the plot window by typing clf open and close parentheses |
| 05:33 | Type bar open and close parentheses year comma profit comma fill equal to False comma hatch equal to inside single quotes slanting line and press Enter. |
| 05:54 | This will display a bar chart which is not filled and which is hatched with 45o slanting lines |
| 06:02 | Help about matplotlib can be obtained from matplotlib.sourceforge.net/contents.html
More plots can be seen at the following links |
| 06:18 | This brings us to the end of this tutorial.
In this tutorial we learnt to, Plot a pie chart using pie() function |
| 06:28 | Plot a bar chart using bar() function |
| 06:31 | And Access the matplotlib online help |
| 06:34 | Here are some self assessment questions for you to solve. |
| 06:38 | What statement can be issued to generate a bar chart with vertical line hatching? |
| 06:45 | And the answer is, bar x comma y comma fill is equal to False comma hatch is equal to a vertical line is the correct option to generate a bar chart with vertical line hatching. |
| 07:00 | Please post your timed queries in this forum. |
| 07:04 | Please post your general queries on Python in this forum. |
| 07:09 | FOSSEE team coordinates the TBC project. |
| 07:13 | Spoken Tutorial Project is funded by NMEICT, MHRD, Govt. of India.
For more details, visit this website. |
| 07:23 | This is Trupti Kini from FOSSEE IIT Bombay signing off.
Thank you. |
