seaborn.heatmap¶

seaborn.heatmap(data, vmin=None, vmax=None, cmap=None, center=None, robust=False, annot=None, fmt='.2g', annot_kws=None, linewidths=0, linecolor='white', cbar=True, cbar_kws=None, cbar_ax=None, square=False, xticklabels='auto', yticklabels='auto', mask=None, ax=None, **kwargs)¶

Plot rectangular data as a color-encoded matrix.

This is an Axes-level function and will draw the heatmap into the currently-active Axes if none is provided to the ax argument. Part of this Axes space will be taken and used to plot a colormap, unless cbar is False or a separate Axes is provided to cbar_ax.

Parameters:

data : rectangular dataset 2D dataset that can be coerced into an ndarray. If a Pandas DataFrame is provided, the index/column information will be used to label the columns and rows. vmin, vmax : floats, optional Values to anchor the colormap, otherwise they are inferred from the data and other keyword arguments. cmap : matplotlib colormap name or object, or list of colors, optional The mapping from data values to color space. If not provided, the default will depend on whether center is set. center : float, optional The value at which to center the colormap when plotting divergant data. Using this parameter will change the default cmap if none is specified. robust : bool, optional If True and vmin or vmax are absent, the colormap range is computed with robust quantiles instead of the extreme values. annot : bool or rectangular dataset, optional If True, write the data value in each cell. If an array-like with the same shape as data, then use this to annotate the heatmap instead of the raw data. fmt : string, optional String formatting code to use when adding annotations. annot_kws : dict of key, value mappings, optional Keyword arguments for ax.text when annot is True. linewidths : float, optional Width of the lines that will divide each cell. linecolor : color, optional Color of the lines that will divide each cell. cbar : boolean, optional Whether to draw a colorbar. cbar_kws : dict of key, value mappings, optional Keyword arguments for fig.colorbar. cbar_ax : matplotlib Axes, optional Axes in which to draw the colorbar, otherwise take space from the main Axes. square : boolean, optional If True, set the Axes aspect to “equal” so each cell will be square-shaped. xticklabels, yticklabels : “auto”, bool, list-like, or int, optional If True, plot the column names of the dataframe. If False, don’t plot the column names. If list-like, plot these alternate labels as the xticklabels. If an integer, use the column names but plot only every n label. If “auto”, try to densely plot non-overlapping labels. mask : boolean array or DataFrame, optional If passed, data will not be shown in cells where mask is True. Cells with missing values are automatically masked. ax : matplotlib Axes, optional Axes in which to draw the plot, otherwise use the currently-active Axes. kwargs : other keyword arguments All other keyword arguments are passed to ax.pcolormesh.

Returns:

ax : matplotlib Axes Axes object with the heatmap.

See also

clustermap

Plot a matrix using hierachical clustering to arrange the rows and columns.

Examples

Plot a heatmap for a numpy array:

>>> import numpy as np; np.random.seed(0)
>>> import seaborn as sns; sns.set()
>>> uniform_data = np.random.rand(10, 12)
>>> ax = sns.heatmap(uniform_data)

Change the limits of the colormap:

>>> ax = sns.heatmap(uniform_data, vmin=0, vmax=1)

Plot a heatmap for data centered on 0 with a diverging colormap:

>>> normal_data = np.random.randn(10, 12)
>>> ax = sns.heatmap(normal_data, center=0)

Plot a dataframe with meaningful row and column labels:

>>> flights = sns.load_dataset("flights")
>>> flights = flights.pivot("month", "year", "passengers")
>>> ax = sns.heatmap(flights)

Annotate each cell with the numeric value using integer formatting:

>>> ax = sns.heatmap(flights, annot=True, fmt="d")

Add lines between each cell:

>>> ax = sns.heatmap(flights, linewidths=.5)

Use a different colormap:

>>> ax = sns.heatmap(flights, cmap="YlGnBu")

Center the colormap at a specific value:

>>> ax = sns.heatmap(flights, center=flights.loc["January", 1955])

Plot every other column label and don’t plot row labels:

>>> data = np.random.randn(50, 20)
>>> ax = sns.heatmap(data, xticklabels=2, yticklabels=False)

Don’t draw a colorbar:

>>> ax = sns.heatmap(flights, cbar=False)

Use different axes for the colorbar:

>>> grid_kws = {"height_ratios": (.9, .05), "hspace": .3}
>>> f, (ax, cbar_ax) = plt.subplots(2, gridspec_kw=grid_kws)
>>> ax = sns.heatmap(flights, ax=ax,
...                  cbar_ax=cbar_ax,
...                  cbar_kws={"orientation": "horizontal"})

Use a mask to plot only part of a matrix

>>> corr = np.corrcoef(np.random.randn(10, 200))
>>> mask = np.zeros_like(corr)
>>> mask[np.triu_indices_from(mask)] = True
>>> with sns.axes_style("white"):
...     ax = sns.heatmap(corr, mask=mask, vmax=.3, square=True)