I created a 4D scatter plot graph to represent different temperatures in a specific area. When I create the legend, the legend shows the correct symbol and color but adds a line through it. The code I'm using is:
colors=['b', 'c', 'y', 'm', 'r']
lo = plt.Line2D(range(10), range(10), marker='x', color=colors[0])
ll = plt.Line2D(range(10), range(10), marker='o', color=colors[0])
l = plt.Line2D(range(10), range(10), marker='o',color=colors[1])
a = plt.Line2D(range(10), range(10), marker='o',color=colors[2])
h = plt.Line2D(range(10), range(10), marker='o',color=colors[3])
hh = plt.Line2D(range(10), range(10), marker='o',color=colors[4])
ho = plt.Line2D(range(10), range(10), marker='x', color=colors[4])
plt.legend((lo,ll,l,a, h, hh, ho),('Low Outlier', 'LoLo','Lo', 'Average', 'Hi', 'HiHi', 'High Outlier'),numpoints=1, loc='lower left', ncol=3, fontsize=8)
I tried changing Line2D
to Scatter
and scatter
. Scatter
returned an error and scatter
changed the graph and returned an error.
With scatter
, I changed the range(10)
to the lists containing the data points. Each list contains either the x, y, or z variable.
lo = plt.scatter(xLOutlier, yLOutlier, zLOutlier, marker='x', color=colors[0])
ll = plt.scatter(xLoLo, yLoLo, zLoLo, marker='o', color=colors[0])
l = plt.scatter(xLo, yLo, zLo, marker='o',color=colors[1])
a = plt.scatter(xAverage, yAverage, zAverage, marker='o',color=colors[2])
h = plt.scatter(xHi, yHi, zHi, marker='o',color=colors[3])
hh = plt.scatter(xHiHi, yHiHi, zHiHi, marker='o',color=colors[4])
ho = plt.scatter(xHOutlier, yHOutlier, zHOutlier, marker='x', color=colors[4])
plt.legend((lo,ll,l,a, h, hh, ho),('Low Outlier', 'LoLo','Lo', 'Average', 'Hi', 'HiHi', 'High Outlier'),scatterpoints=1, loc='lower left', ncol=3, fontsize=8)
When I run this, the legend no longer exists, it is a small white box in the corner with nothing in it.
Any advice?
Best Answer
2D scatter plot
Using the
scatter
method of thematplotlib.pyplot
module should work (at least with matplotlib 1.2.1 with Python 2.7.5), as in the example code below. Also, if you are using scatter plots, usescatterpoints=1
rather thannumpoints=1
in the legend call to have only one point for each legend entry.In the code below I've used random values rather than plotting the same range over and over, making all the plots visible (i.e. not overlapping each other).
3D scatter plot
To plot a scatter in 3D, use the
plot
method, as the legend does not supportPatch3DCollection
as is returned by thescatter
method of anAxes3D
instance. To specify the markerstyle you can include this as a positional argument in the method call, as seen in the example below. Optionally one can include argument to both thelinestyle
andmarker
parameters.