pynbody.plot.generic.gauss_kde

pynbody.plot.generic.gauss_kde(xo, yo, weights=None, mass=None, gridsize=(100, 100), nbins=None, make_plot=True, nmin=None, nmax=None, **kwargs)

Plot 2D gaussian kernel density estimate (KDE) given values at points (x, y).

Behavior changes depending on which keywords are passed:

If a weights array is supplied, produce a weighted KDE.

If a mass array is supplied, a mass density is computed.

If both weights and mass are supplied, a mass-averaged KDE of the weights is computed.

By default, norm=False is passed to fast_kde() meaning that the result returned is not normalized such that the integral over the area equals one.

Since this function produces a density estimate, the units of the

output grid are different than for the output of hist2d(). To get to the same units, you must multiply by the size of the cells.

Input:

xo: array

yo: array

Optional keywords:

mass: numpy array of same length as x and y

particle masses to be used for weighting

weights: numpy array of same length as x and y

if weights is passed, color corresponds to the mean value of weights in each cell

nmin: float (default None)

if weights and mass are both specified, the mass-weighted contours are only drawn where the mass exceeds nmin.

gridsize: (int, int) (default: 100,100)

size of grid for computing the density estimate

nbins: int

number of bins for the histogram - if specified, gridsize is set to (nbins,nbins)

make_plot: boolean (default: True)

whether or not to produce a plot

Keywords passed to fast_kde():

norm: boolean (default: False)

If False, the output is only corrected for the kernel. If True, the result is normalized such that the integral over the area yields 1.

nocorrelation: (default: False) If True, the correlation

between the x and y coords will be ignored when preforming the KDE.

Keywords passed to make_contour_plot():

x_range: list, array, or tuple

size(x_range) must be 2. Specifies the X range.

y_range: tuple

size(y_range) must be 2. Specifies the Y range.

nlevels: int

number of levels to use for the contours

logscale: boolean

whether to use log or linear spaced contours

colorbar: boolean

draw a colorbar

scalemin: float

minimum value to use for the color scale

scalemax: float

maximum value to use for the color scale