### Ch 3 Plotting with PyPlot

Sumita Arora Book Exercise Solution

**Type A: Short Answer Questions / Conceptual Questions**

#### 1. Name the library of which the PyPlot is an interface.

**Ans:** Matplotlib

##### 2. Write the statement to import PyPlot in your script.

**Ans:** import matplotlib.pyplot

OR

import matplotlib.pyplot as plt

##### 3. Name the functions to create the following:

(a) line chart (b) bar chart (c) horizontal bar chart (d) histogram

(e) scatter chart (t) boxplot (g) pie chart

**Ans: ** (a) plot( )

(b) bar( )

(c) barh( )

(d) hist( )

(e) scatter( ) or plot( )

(f) boxplot( )

(g) pie( )

##### 4. What is a line chart?

**Ans:** Line Chart is a type of chart which displays information as a series of data points called ‘markers’ connected by straight line segments. A plot( ) function is used to make line chart.

##### 5. What is a scatter chart?

**Ans:** Scatter chart is a graph of plotted points on two axes that show the relationship between two sets of data. A scatter( ) method of pyplot interface is use to make the scatter chart. A scatter chart can be created by using plot( ) method also.

##### 6. What is a pie chart?

**Ans:** Pie chart is a type of chart or graph in which a circle is divided into sections that each represent a proportion of the whole. A pie() method of pyplot interface is use to make pie chart.

##### 7. What is a bar chart?

**Ans:** Bar chart is a type of graph or chart, which represent the numerical data graphically using bars of different height. It can draw vertically or horizontally. A bar() and barh( ) method of pyplot interface is use to create bar chart.

##### 8. What is a histogram?

**Ans:** Histogram is a summarisation tool for discrete or continuous data.

##### 9. What is a boxplot?

**Ans:** A histogram is basically used to represent data provided in a form of some groups. It is accurate method for the graphical representation of numerical data distribution.

##### 10. What is a frequency polygon?

**Ans:** Frequency polygon is a type of frequency distribution graph. In this, number of observations is marked with a single point at the midpoint of an interval. A straight line then connects each set of points.

##### 11. Name the function to label axes.

**Ans:** xlabel( ) and ylabel( )

##### 12. Name the function to give a title to a plot.

**Ans:** title( )

##### 13. Name the function to set figure size of a plot.

**Ans:** figure(figsize=(w, l))

##### 14. Name the function to set limits for the axes.

**Ans:** matplotlib.pyplot.xlim( ), matplotlib.pyplot.ylim( )

##### 15. Name the function to show legends on a plot.

**Ans:** matplotlib.pyplot.legend(loc=value)

or

plt.legend()

##### 16. Name the function to add ticks on axes.

**Ans:** **For x-axis:**

matplotlib.pyplot.xticks(sequence tick data points [, sequence tick lable])

**For y-axis:**

matplotlib.pyplot.yticks(sequence tick data points [, sequence tick lable])