statsmodels.graphics.gofplots.qqplot_2samples¶

statsmodels.graphics.gofplots.
qqplot_2samples
(data1, data2, xlabel=None, ylabel=None, line=None, ax=None)[source]¶ QQ Plot of two samples’ quantiles.
Can take either two ProbPlot instances or two arraylike objects. In the case of the latter, both inputs will be converted to ProbPlot instances using only the default values  so use ProbPlot instances if finergrained control of the quantile computations is required.
 Parameters
 data1{array_like,
ProbPlot
} Data to plot along x axis.
 data2{array_like,
ProbPlot
} Data to plot along y axis. Does not need to have the same number of observations as data 1.
 xlabel{
None
,str
} Userprovided labels for the xaxis. If None (default), other values are used.
 ylabel{
None
,str
} Userprovided labels for the yaxis. If None (default), other values are used.
 line{
None
, “45”, “s”, “r”, q”} Options for the reference line to which the data is compared:
“45”  45degree line
“s”  standardized line, the expected order statistics are scaled by the standard deviation of the given sample and have the mean added to them
“r”  A regression line is fit
“q”  A line is fit through the quartiles.
None  by default no reference line is added to the plot.
 ax
AxesSubplot
,optional
If given, this subplot is used to plot in instead of a new figure being created.
 data1{array_like,
 Returns
Figure
If ax is None, the created figure. Otherwise the figure to which ax is connected.
See also
Notes
Depends on matplotlib.
If data1 and data2 are not ProbPlot instances, instances will be created using the default parameters. Therefore, it is recommended to use ProbPlot instance if finegrained control is needed in the computation of the quantiles.
Examples
>>> import statsmodels.api as sm >>> import numpy as np >>> import matplotlib.pyplot as plt >>> from statsmodels.graphics.gofplots import qqplot_2samples >>> x = np.random.normal(loc=8.5, scale=2.5, size=37) >>> y = np.random.normal(loc=8.0, scale=3.0, size=37) >>> pp_x = sm.ProbPlot(x) >>> pp_y = sm.ProbPlot(y) >>> qqplot_2samples(pp_x, pp_y) >>> plt.show()
(Source code, png, hires.png, pdf)
>>> fig = qqplot_2samples(pp_x, pp_y, xlabel=None, ylabel=None, ... line=None, ax=None)