# kwant.plotter.spectrum¶

kwant.plotter.spectrum(syst, x, y=None, params=None, mask=None, file=None, show=True, dpi=None, fig_size=None, ax=None)[source]

Plot the spectrum of a Hamiltonian as a function of 1 or 2 parameters

Parameters
systkwant.system.FiniteSystem or callable

If a function, then it must take named parameters and return the Hamiltonian as a dense matrix.

xpair (name, values)

Parameter to ham that will be varied. Consists of the parameter name, and a sequence of parameter values.

ypair (name, values), optional

Used for 3D plots (same as x). If provided, then the cartesian product of the x values and these values will be used as a grid over which to evaluate the spectrum.

paramsdict, optional

The rest of the parameters to ham, which will be kept constant.

Takes the parameters specified by x and y and returns True if the spectrum should not be calculated for the given parameter values.

filestring or file object or None

The output file. If None, output will be shown instead.

showbool

Whether matplotlib.pyplot.show() is to be called, and the output is to be shown immediately. Defaults to True.

dpifloat

Number of pixels per inch. If not set the matplotlib default is used.

fig_sizetuple

Figure size (width, height) in inches. If not set, the default matplotlib value is used.

axmatplotlib.axes.Axes instance or None

If ax is not None, no new figure is created, but the plot is done within the existing Axes ax. in this case, file, show, dpi and fig_size are ignored.

Returns
figmatplotlib figure

A figure with the output if ax is not set, else None.

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