Module 5: PyBer with Matplotlib

Object-Oriented Interface Function fig, ax = plt.subplots(figsize=(w, h))

Change the size of the figure in pixels. Add this in the subplots() function.

plt.figure(figsize=(w, h))

Change the size of the figure in pixels. Added on the first line of the script.

plt.gca()

get current axes. example (plt.gca()invert_yaxis( )

plt.xlabel()

labels x axis of plot

plt.ylabel()

labels y axis of plot

plt.legend()

makes a legend for the plot

errorbar()

shows a plot with error bars at each data point x = 1:4; y = [5,8,13,9]; err = [1,2,4,1]; h = errorbar(x, y, err);

% (magic command)

The % sign is sometimes called the magic command. When you run a cell that starts with %, "magic" happens behind the scenes and sets the back-end processor used for charts.

plt.pie()

The function to create a pie chart

barh()

a horizontal bar graph

Matrix

a two-dimensional data structure, or a list of lists, in which numbers are arranged into rows and columns

plt.barh(x,y)

Add a Horizontal Bar Chart

plt.bar(x,y)

Add a Vertical Bar Chart

Object-Oriented Interface Function ax.grid()

Add a grid to the chart.

plt.grid()

Add a grid to the chart.

Object-Oriented Interface Function ax.plot(x, y, label='line')

Add a label that will be added to the legend.

plt.plot(x, y, label='line')

Add a label that will be added to the legend.

Object-Oriented Interface Function ax.set_xlabel('x label')

Add a label to the x-axis.

plt.xlabel('x label')

Add a label to the x-axis.

Object-Oriented Interface Function ax.set_ylabel('y label')

Add a label to the y-axis.

plt.ylabel('y label')

Add a label to the y-axis.

Object-Oriented Interface Function ax.legend()

Add a legend.

Object-Oriented Interface Function ax.set_title("Title")

Add a title.

plt.title("Title")

Add a title.

fig, ax = plt.subplots() ax.errorbar(x_axis, y_axis, yerr=stdev, capsize=3) plt.show()

Adding error bars and a capsize using the object-oriented approach

plt.bar(x_axis, y_axis, yerr=stdev, capsize=3)

Adding error bars and caps to a bar chart using the MATLAB approach

regression analysis

An analytic technique where a series of input variables are examined in relation to their corresponding output results in order to develop a mathematical or statistical relationship.

Object-Oriented Interface Function ax.set_ylim(min, max)

Sets the min and max range of the y-axis.

import matplotlib.pyplot as plt

In order to create a graph in Python, you need to include

The Numpy Module

NumPy is a numerical mathematics library that can be used to create arrays or matrices of numbers.

list comprehension

Python rules for creating lists intelligently s = [x for x in range(1:51) if x%2 == 0] [2, 4, 6, 8, 10, 12, 14, 16, etc]

plt.savefig("add a path and figure extension")

Save the figure with the given extension. Added at the end of the script.

Object-Oriented Interface Function ** plt.savefig("add a path and figure extension")

Saves the figure with the given extension. Added at the end of your script.

plt.xlim(min, max)

Set the min and max range of the x-axis.

plt.ylim(min, max)

Set the min and max range of the y-axis.

Object-Oriented Interface Function ax.set_xlim(min, max)

Sets the min and max range of the x-axis.

plt.plot()

The purpose of __________ is to create the figure with the current axes.

explode values

To "explode" a pie chart means to make one of the wedges of the pie chart to stand out.

ax.bar(x,y)

To create a bar chart using the object-oriented interface method

fig, ax = plt.subplots()

To create a figure, use __________ when using the object-orientated interface.

ax.barh(x,y)

To create a horizontal bar chart using the object-oriented interface method

plt.plot() Function to change color, width, and marker

To declare the parameters for line color, width, and marker, we use color=, width=, and marker=, respectively, inside the plt.plot() function.

stdev = statistics.stdev(y_axis) stdev

To get the standard deviation of the values in the y-axis

%matplotlib inline

To make sure our plots are displayed inline within the Jupyter Notebook directly below the code cell that produced it, we need to add ________________ to the first cell

Tuple

Tuples are used to store multiple items in a single variable. Tuple is one of 4 built-in data types in Python used to store collections of data, the other 3 are List, Set, and Dictionary, all with different qualities and usage. A tuple is a collection which is ordered and unchangeable. Tuples are written with round brackets. example: tuple = ("apple", "banana", "cherry")

ax.plot()

When we switch from using MATLAB to the object-oriented interface method, we use __________ instead of plt.plot().

plt.plot(x_axis, y_axis, 'o')

When we use the plt.plot() function to create a scatter plot, we need to add a lowercase "o" as a parameter inside the parentheses. This switches the plot from a line chart to a scatter plot.

plt.show()

displays the graph

plt.title()

to add a title to your chart

plt.errorbar(x_axis, y_axis, yerr=stdev)

to create a line chart with error bars