#CONTOUR PLOT HOW TO#
#CONTOUR PLOT SOFTWARE#

The constant value of f when all of the values So this is still f of x, y and then some expression of those guys but this line might represent Looking in the input space of that function as a whole. Two-dimensional input and a one-dimensional output. So this is the same function that we were just looking at, but each of these lines represents a constant output of the function so it's important to realize we're still representing a function that has a And this is that same function that we were just looking at. I'm going to switch over toĪ two-dimensional graph here. Not all of them, it's not perfect, but it does give a very good idea. And now we have something two-dimensional, and it still represents some of the outputs of our function. Of z component at the moment, and we're just going to chop it down, squish them all nice and flat, on to the x, y plane. So what that means, each of them has some kind Take all these contour lines and I'm going to squish themĭown on to the x, y plane. We're still in three-dimensions so we're not done yet. Slices cut into the graph?' So I'm going to draw on all of the points where those slices cut into the graph and these are called contour lines. The output of the function as the height off of the x, y plane these represent constant Now in terms of our graph, what that means is that these represent constant And the rest of these guys, they're all still constant values of z. Parallel to the x, y plane but it's distance from the Keep it constant, but let it increase by one to negative one we get a new plane, still This is the z-axis over here and when we fix that to be negative two and let x and y run freely So the bottom one here represents the value z It with various planes that are all parallel to the x, y plane and let's think for a moment about what these guys represent. It's known as a contour plot and the idea of a contour plot is that we're going to take this graph and slice it a bunch of times. That you'll see if you're reading a textbook or if someone These graphs two-dimensionally just by scribbling down on a So here I'm going toĭescribe a way that you can represent these functions and

#CONTOUR PLOT SOFTWARE#

Kind of graphing software and when you take a static image of it it's not always clear what's going on. And graphs are great but they're kinda clunky to draw. Something like f of x, y equals and then just some expression that has aīunch of x's and y's in it. You can find more Matplotlib tutorials here.A three-dimensional graph, and that means that it's representing some kind of function that has a two-dimensional inputĪnd a one-dimension output. We can also use the colorbar() function to add a labeled color bar next to the plot: plt.

#CONTOUR PLOT HOW TO#

The following code shows how to use the contourf() function to create a filled contour plot for the same data we used in the previous example: plt. Example 2: Filled Contour Plot in MatplotlibĪ filled contour plot is similar to a contour plot except that the spaces between the lines are filled. We chose to use the cmap ‘Reds’ but you can find a complete list of colormap options on the Matplotlib documentation page. contour(X, Y, Z, levels= 30, cmap=' Reds') We can also specify more lines to be used in the plot with the levels argument: plt. When a single color is used for the plot, the dashed lines represent negative values and the solid lines represent positive values.Īn alternative is to specify a colormap using the cmap argument. We can use the following code to create a contour plot for the data: import matplotlib.pyplot as plt Suppose we have the following data in Python: import numpy as np The following examples show how to use these two functions in practice. You can create a contour plot in Matplotlib by using the following two functions: A contour plot is a type of plot that allows us to visualize three-dimensional data in two dimensions by using contours.

Contour plot