#Contour plot in python how to#

Set the projection to 3d by defining axes object = add_subplot().

Generate and set the size of the figure, using plt.figure() function and figsize() method.

Import from mpl_toolkits.mplot3d import Axes3D library.

We take x and y values in a one-dimensional array using the array method of numpy, then we need to convert them into a two-dimensional array, so we use the meshgrid function of numpy.

levels: The number and positions of the contour lines are determined.

z: Specifies the height over which contour is drawn.

x and y: Specifies 2D or 1D numpy array for plotting.

In matplotlib, matplotlib.pyplot includes a method contour to make it easy to construct contour plots due to its widespread use. When we plot X and Y as our variables, the response Z is shown as slices on the X-Y plane, which is why contours are sometimes referred to as Z-slices.Ĭontour plots are commonly used in meteorological departments to illustrate densities, elevations, or mountain heights.

We take x and y values in a one-dimensional array using the linspace method of numpy, then we need to convert them into a two-dimensional array, so we use meshgrid function of numpy.Īlso, check Matplotlib xlim – Complete Guide Matplotlib 2d contour plotĬontour plots, also known as level plots, are a multivariate analytic tool that allows you to visualize 3-D plots in 2-D space.

Then we use the z to plot on a map with axes x and y using the surface plot to get the 3D effects.

Here we need x and y values, and from x and y we compute the value of z called height.

Here our main motive is to generate two-dimensional data using matplotlib and plot it with three-dimensional effects i.e Surface. The syntax to create the surface plot: ax.plot_surface(X, Y, Z) To create a surface plot we import Matplotlib’s mpl_toolkits.mplot3d toolkit which has functions to create a 3D surface plot. Importing the mplot3d package enables the 3d plots.Ī surface plot is the representation of a three-dimensional dataset. But after release 1.0, you can develop 3d utilities upon 2d utilities.

Finally, the legend() function is used to assign the given name for the plots and the graph is displayed using the show() function.Before the release of the 1.0 version, matplotlib is used only used for two-dimensional plotting.The legend_elements() is a function that is used to check how many legend entries are to be created.The contour () function is used to generate the contour plot for the given values.

#Contour plot in python how to#

The value of z specifies how to slice the 3-D graph into a 2-D plane here two values are received in order to plot 2 contour plots.Finally, the show() function is used to display the graph.Ĭreating a legend in matplotlib import matplotlib.pyplot as plt.Contour() is a function that is used to generate the contour plot for the given values.The value of z specifies how to slice the 3-D graph into a 2-D plane.The meshgrid() function is used to create a grid layout for the specified values.The linspace() is a function in NumPy that is used to specify the range of the axis.Import matplotlib module to plot the contour plot and NumPy to number the axis and create grid layout.

Create a contour plot in matplotlib import matplotlib.pyplot as plt The main purpose of a contour plot is to display a 3-Dimensional surface in a 2-Dimensional plot. Here, by slices, we mean that a 3-D graph is cut into equal partitions along an axis and the boundaries are merged together in a 2-D plane. What is a contour plot?Ī contour plot is a technique of plotting constant z slices called a contour on a 2-Dimensional format to represent a 3-dimensional surface. Matplotlib is a data visualization library in python which is used to represent data in the form of plots and graphs. To do this we need to know about matplotlib library. In this tutorial, we are going to see how to create a legend for a contour plot in matplotlib in Python.