Difference between revisions of "Python-3.4.3/C2/Subplots/English"

containing title, name of the production team along with the logo of MHRD

Objectives

1. Create and switch between subplots.

System Specifications

• Ubuntu Linux 14.04 operating system
• Python 3.4.3
• IPython 5.1.0

Pre-requisites

• run basic Python commands on the ipython console
• use Plots interactively
• Embellish a plot

If not, see the pre-requisite Python tutorials on this website.

ipython3

Now, type ipython3 and press Enter.

percentage pylab and press Enter.

Type percentage pylab and press Enter

[IPython Terminal]

x = linspace(0, 50, 500)

plot(x, cos(x))

y = linspace(0, 5, 100)

plot(y, y ** 2)

To compare two plots we draw the plots in the same plotting area.

Let us now create two plots, a cosine plot and an exponential curve in the same plotting area.

Type

x equals to linspace inside brackets 0 comma 50 comma 500 and press enter

plot inside brackets x comma cos(x).

Type

y equals to linspace inside brackets 0 comma 5 comma 100.

plot inside brackets y comma y square.

[Plot Window]

Here the two plots have different regular axes so we cannot draw overlaid plots.

[IPython Terminal]

clf()

subplot(2, 1, 1)

In such cases we can draw subplots.

We use subplot command to accomplish this

Type

clf()

subplot inside the brackets 2 comma 1 comma 1

The first argument is the number of rows of subplots that must be created.

Here the first argument is 2, to split the plot horizontally.

The second argument is the number of columns of subplots that must be created.

Here the second argument is 1, so plot will not split vertically.

The last argument specifies the serial number for subplot.

Here we passed 1 as the argument, which creates the upper subplot

subplot(2, 1, 2)

subplot inside the brackets 2 comma 1 comma 2

The lower subplot is created.

x = linspace(0, 50, 500)

subplot(2, 1, 1)

plot(x, cos(x))

y = linspace(0, 5, 100)

subplot(2, 1, 2)

plot(y, y ** 2)

Type

subplot inside brackets 2 comma 1 comma 1

plot inside brackets x comma cos(x)

Now type

subplot inside brackets 2 comma 1 comma 2

plot y comma y square

The top subplot holds a cosine curve and the bottom subplot holds a parabola.

It is clear from the two subplots that both have different regular axes.

For the cosine curve x-axis varies from 0 to 50 and y-axis varies from minus 1 to 1.

For the parabolic curve x-axis varies from 0 to 5 and y-axis varies from 0 to 25.

clf()

Exercise 1

• Pressure, Volume and Temperatures are held by the equation PV = nRT where nR is a constant.

• Assume nR =0.01 Joules/Kelvin and T = 200K. V can be in the range from 21cc to 100cc.

Pressure, Volume and Temperatures are held by the equation Pv equals to nRT where nR is a constant.

Assume nR equals to 0.01 Joules per Kelvin and T equals to 200K. V can be in the range from 21cc to 100cc.

Draw two different plots as subplots:

• Pressure v/s Volume plot and

• Pressure v/s Temperature plot.

v = linspace(21, 100, 500)

v equals to linspace inside brackets 21 comma 100 comma 500

subplot(2, 1, 1)

plot(v, 2.0/v)

subplot(2 comma 1 comma 1)

plot(v comma 2 point 0 by v)

We know that nRT is a constant which is equal to 2.0 since nR = equals to 0.01 Joules per Kelvin and T equals to 200 Kelvin

subplot(2, 1, 2)

plot(200, 2.0/v)

subplot(2 comma 1 comma 2)

plot(200 comma 2 point 0 divided by v)

t = linspace(200, 200, 500)

So we will create same number of points for temperature.

Type

t equals to linspace inside brackets 200 comma 200 comma 500.

plot(t, 2.0/v)

Type

plot inside brackets t comma 2 point 0 divided by v

Summary slide

1. Create subplots and to switch between them.

Evaluation

1. Which of the following is correct.

• • subplot inside brackets numRows comma numCols, plotNum
  • subplot inside brackets numRows comma numCols
  • subplot inside brackets numCols comma numRows

Solutions

1. The subplot command takes three arguments namely the number of rows , number of columns and the plot number.

Forum

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Acknowledgement

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Thank You

Thank You