genieclust.plots

Various plotting functions

genieclust.plots.plot_scatter(X, y=None, labels=None, axis=None, title=None, xlabel=None, ylabel=None, xlim=None, ylim=None, **kwargs)

Draws a scatter plot

Parameters:
Xarray_like

Either a two-column matrix that gives the x and y coordinates of the points or a vector of length n. In the latter case, y must be a vector of length n as well.

yNone or array_like

The y coordinates of the n points in the case where X is a vector.

labelsNone or array_like

A vector of n integer labels that correspond to each point in X, that gives its plot style.

axis, title, xlabel, ylabel, xlim, ylimNone or object

If not None, values passed to matplotlib.pyplot.axis, matplotlib.pyplot.title, etc.

**kwargsCollection properties

Further arguments to matplotlib.pyplot.scatter.

Notes

If X is a two-column matrix, then plot_scatter(X) is equivalent to plot_scatter(X[:,0], X[:,1]).

Unlike in matplotlib.pyplot.scatter, for any fixed j, all points X[i,:] such that labels[i] == j are always drawn in the same way, no matter the max(labels). In particular, labels 0, 1, 2, and 3 correspond to black, red, green, and blue, respectively.

This function was inspired by the plot() function from the R package graphics.

Examples

An example scatter plots where each point is assigned one of two distinct labels:

>>> n = np.r_[100, 50]
>>> X = np.r_[np.random.randn(n[0], 2), np.random.randn(n[1], 2)+2.0]
>>> l = np.repeat([0, 1], n)
>>> genieclust.plots.plot_scatter(X, labels=l)
>>> plt.show()                                   

(png, hires.png, pdf)

_images/genieclust_plots-1.png

Here are the first 10 plotting styles:

>>> ncol = len(genieclust.plots.col)
>>> nmrk = len(genieclust.plots.mrk)
>>> mrk_recycled = np.tile(
...     genieclust.plots.mrk,
...     int(np.ceil(ncol/nmrk)))[:ncol]
>>> for i in range(10):                               
...     plt.text(                                     
...         i, 0, i, horizontalalignment="center")    
...     plt.plot(                                     
...         i, 1, marker=mrk_recycled[i],             
...         color=genieclust.plots.col[i],            
...         markersize=25)                            
>>> plt.title("Plotting styles for labels=0,1,...,9") 
>>> plt.ylim(-3,4)                                    
>>> plt.axis("off")                                   
>>> plt.show()                                        

(png, hires.png, pdf)

_images/genieclust_plots-2.png
genieclust.plots.plot_segments(pairs, X, y=None, style='k-', **kwargs)

Draws a set of disjoint line segments

Parameters:
pairsarray_like

A two-column matrix that gives the pairs of indices defining the line segments to draw.

Xarray_like

Either a two-column matrix that gives the x and y coordinates of the points or a vector of length n. In the latter case, y must be a vector of length n as well.

yNone or array_like

The y coordinates of the n points in the case where X is a vector.

style:

See matplotlib.pyplot.plot.

**kwargsCollection properties

Further arguments to matplotlib.pyplot.plot.

Notes

The function draws a set of disjoint line segments from (X[pairs[i,0],0], X[pairs[i,0],1]) to (X[pairs[i,1],0], X[pairs[i,1],1]) for all i from 0 to pairs.shape[0]-1.

matplotlib.pyplot.plot is called only once. Therefore, you can expect it to be pretty pretty fast.

Examples

Plotting the convex hull of a point set:

>>> import scipy.spatial
>>> X = np.random.randn(100, 2)
>>> hull = scipy.spatial.ConvexHull(X)
>>> genieclust.plots.plot_scatter(X)
>>> genieclust.plots.plot_segments(hull.simplices, X, style="r--")
>>> plt.show()                                 

(png, hires.png, pdf)

_images/genieclust_plots-3.png

Plotting the minimum spanning tree:

>>> X = np.random.randn(100, 2)
>>> mst = genieclust.internal.mst_from_distance(X, "euclidean")
>>> genieclust.plots.plot_scatter(X)
>>> genieclust.plots.plot_segments(mst[1], X, style="m-.")
>>> plt.axis("equal")                          
>>> plt.show()                                 

(png, hires.png, pdf)

_images/genieclust_plots-4.png