colormaps module¶

Module for commonly used colormaps and palettes for visualizing geospatial data.

`create_colormap(cmap='gray', colors=None, discrete=False, label=None, width=8.0, height=0.4, orientation='horizontal', vmin=0, vmax=1.0, axis_off=False, show_name=False, font_size=12, **kwargs)` ¶

Plot a matplotlib colormap.

Parameters:

Name	Type	Description	Default
`cmap`	`str`	Matplotlib colormap. Defaults to "gray". See https://matplotlib.org/3.3.4/tutorials/colors/colormaps.html#sphx-glr-tutorials-colors-colormaps-py for options.	`'gray'`
`colors`	`list`	A list of custom colors to create a colormap. Defaults to None.	`None`
`discrete`	`bool`	Whether to create a discrete colorbar. Defaults to False.	`False`
`label`	`str`	Label for the colorbar. Defaults to None.	`None`
`width`	`float`	The width of the colormap. Defaults to 8.0.	`8.0`
`height`	`float`	The height of the colormap. Defaults to 0.4.	`0.4`
`orientation`	`str`	The orientation of the colormap. Defaults to "horizontal".	`'horizontal'`
`vmin`	`float`	The minimum value range. Defaults to 0.	`0`
`vmax`	`float`	The maximum value range. Defaults to 1.0.	`1.0`
`axis_off`	`bool`	Whether to turn axis off. Defaults to False.	`False`
`show_name`	`bool`	Whether to show the colormap name. Defaults to False.	`False`
`font_size`	`int`	Font size of the text. Defaults to 12.	`12`

Source code in leafmap/colormaps.py

def create_colormap(
    cmap: Optional[str] = "gray",
    colors: Optional[List] = None,
    discrete: Optional[bool] = False,
    label: Optional[str] = None,
    width: Optional[float] = 8.0,
    height: Optional[float] = 0.4,
    orientation: Optional[str] = "horizontal",
    vmin: Optional[float] = 0,
    vmax: Optional[float] = 1.0,
    axis_off: Optional[bool] = False,
    show_name: Optional[bool] = False,
    font_size: Optional[int] = 12,
    **kwargs
) -> None:
    """Plot a matplotlib colormap.

    Args:
        cmap (str, optional): Matplotlib colormap. Defaults to "gray". See https://matplotlib.org/3.3.4/tutorials/colors/colormaps.html#sphx-glr-tutorials-colors-colormaps-py for options.
        colors (list, optional): A list of custom colors to create a colormap. Defaults to None.
        discrete (bool, optional): Whether to create a discrete colorbar. Defaults to False.
        label (str, optional): Label for the colorbar. Defaults to None.
        width (float, optional): The width of the colormap. Defaults to 8.0.
        height (float, optional): The height of the colormap. Defaults to 0.4.
        orientation (str, optional): The orientation of the colormap. Defaults to "horizontal".
        vmin (float, optional): The minimum value range. Defaults to 0.
        vmax (float, optional): The maximum value range. Defaults to 1.0.
        axis_off (bool, optional): Whether to turn axis off. Defaults to False.
        show_name (bool, optional): Whether to show the colormap name. Defaults to False.
        font_size (int, optional): Font size of the text. Defaults to 12.
    """
    fig, ax = plt.subplots(figsize=(width, height))

    if colors is not None and (isinstance(colors, list) or isinstance(colors, tuple)):
        hexcodes = to_hex_colors(list(colors))
        if discrete:
            col_map = mpl.colors.ListedColormap(hexcodes)
            vals = np.linspace(vmin, vmax, col_map.N + 1)
            norm = mpl.colors.BoundaryNorm(vals, col_map.N)

        else:
            col_map = mpl.colors.LinearSegmentedColormap.from_list(
                "custom", hexcodes, N=256
            )
            norm = mpl.colors.Normalize(vmin=vmin, vmax=vmax)
    else:
        col_map = mpl.colormaps[cmap]
        norm = mpl.colors.Normalize(vmin=vmin, vmax=vmax)

    cb = mpl.colorbar.ColorbarBase(
        ax, norm=norm, cmap=col_map, orientation=orientation, **kwargs
    )

    if label is not None and isinstance(label, str):
        cb.set_label(label, fontsize=font_size)

    if axis_off:
        ax.set_axis_off()
    ax.tick_params(labelsize=font_size)

    if show_name:
        pos = list(ax.get_position().bounds)
        x_text = pos[0] - 0.01
        y_text = pos[1] + pos[3] / 2.0
        fig.text(x_text, y_text, cmap, va="center", ha="right", fontsize=font_size)

    return fig

`get_colorbar(colors, vmin=0, vmax=1, width=6.0, height=0.4, orientation='horizontal', discrete=False)` ¶

Creates a colorbar based on custom colors.

Parameters:

Name	Type	Description	Default
`colors`	`list`	A list of hex colors.	required
`vmin`	`float`	The minimum value range. Defaults to 0.	`0`
`vmax`	`float`	The maximum value range. Defaults to 1.0.	`1`
`width`	`float`	The width of the colormap. Defaults to 6.0.	`6.0`
`height`	`float`	The height of the colormap. Defaults to 0.4.	`0.4`
`orientation`	`str`	The orientation of the colormap. Defaults to "horizontal".	`'horizontal'`
`discrete`	`bool`	Whether to create a discrete colormap.	`False`

Source code in leafmap/colormaps.py

def get_colorbar(
    colors: List,
    vmin: Optional[float] = 0,
    vmax: Optional[float] = 1,
    width: Optional[float] = 6.0,
    height: Optional[float] = 0.4,
    orientation: Optional[str] = "horizontal",
    discrete: Optional[bool] = False,
) -> None:
    """Creates a colorbar based on custom colors.

    Args:
        colors (list): A list of hex colors.
        vmin (float, optional): The minimum value range. Defaults to 0.
        vmax (float, optional): The maximum value range. Defaults to 1.0.
        width (float, optional): The width of the colormap. Defaults to 6.0.
        height (float, optional): The height of the colormap. Defaults to 0.4.
        orientation (str, optional): The orientation of the colormap. Defaults to "horizontal".
        discrete (bool, optional): Whether to create a discrete colormap.
    """
    hexcodes = [i if i[0] == "#" else "#" + i for i in colors]
    _, ax = plt.subplots(figsize=(width, height))
    if discrete:
        cmap = mpl.colors.ListedColormap(hexcodes)
        vals = np.linspace(vmin, vmax, cmap.N + 1)
        norm = mpl.colors.BoundaryNorm(vals, cmap.N)
    else:
        cmap = mpl.colors.LinearSegmentedColormap.from_list("custom", hexcodes, N=256)
        norm = mpl.colors.Normalize(vmin=vmin, vmax=vmax)
    mpl.colorbar.ColorbarBase(ax, norm=norm, cmap=cmap, orientation=orientation)
    plt.show()

`get_palette(cmap_name=None, n_class=None, hashtag=False)` ¶

Get a palette from a matplotlib colormap. See the list of colormaps at https://matplotlib.org/stable/tutorials/colors/colormaps.html.

Parameters:

Name	Type	Description	Default
`cmap_name`	`str`	The name of the matplotlib colormap. Defaults to None.	`None`
`n_class`	`int`	The number of colors. Defaults to None.	`None`
`hashtag`	`bool`	Whether to return a list of hex colors. Defaults to False.	`False`

Returns:

Type	Description
`list`	A list of hex colors.

Source code in leafmap/colormaps.py

def get_palette(
    cmap_name: Optional[str] = None,
    n_class: Optional[int] = None,
    hashtag: Optional[bool] = False,
) -> List[str]:
    """Get a palette from a matplotlib colormap. See the list of colormaps at https://matplotlib.org/stable/tutorials/colors/colormaps.html.

    Args:
        cmap_name (str, optional): The name of the matplotlib colormap. Defaults to None.
        n_class (int, optional): The number of colors. Defaults to None.
        hashtag (bool, optional): Whether to return a list of hex colors. Defaults to False.

    Returns:
        list: A list of hex colors.
    """

    if cmap_name in ["dem", "ndvi", "ndwi"]:
        colors = _palette_dict[cmap_name]
    else:
        cmap = mpl.colormaps[cmap_name]  # Retrieve colormap
        if n_class:
            colors = [
                mpl.colors.rgb2hex(cmap(i / (n_class - 1)))[1:] for i in range(n_class)
            ]
        else:
            colors = [mpl.colors.rgb2hex(cmap(i))[1:] for i in range(cmap.N)]
    if hashtag:
        colors = ["#" + i for i in colors]
    return colors

`list_colormaps(add_extra=False, lowercase=False)` ¶

List all available colormaps. See a complete lost of colormaps at https://matplotlib.org/stable/tutorials/colors/colormaps.html.

Parameters:

Name	Type	Description	Default
`add_extra`	`bool`	If True, include additional colormaps, Default False,	`False`
`lowercase`	`bool`	If True, convert colormaps names to lowercase, Default is False.	`False`

Returns:

Type	Description
`list`	The list of colormap names.

Source code in leafmap/colormaps.py

def list_colormaps(add_extra: bool = False, lowercase: bool = False) -> List:
    """List all available colormaps. See a complete lost of colormaps at https://matplotlib.org/stable/tutorials/colors/colormaps.html.

    Args:
        add_extra (bool, optional): If True, include additional colormaps, Default False,
        lowercase (bool, optional): If True, convert colormaps names to lowercase, Default is False.

    Returns:
        list: The list of colormap names.
    """
    result = plt.colormaps()
    if add_extra:
        result += ["dem", "ndvi", "ndwi"]
    if lowercase:
        result = [i.lower() for i in result]
    result.sort()
    return result

`plot_colormap(cmap='gray', colors=None, discrete=False, label=None, width=8.0, height=0.4, orientation='horizontal', vmin=0, vmax=1.0, axis_off=False, show_name=False, font_size=12, **kwargs)` ¶

Plot a matplotlib colormap.

Parameters:

Name	Type	Description	Default
`cmap`	`str`	Matplotlib colormap. Defaults to "gray". See https://matplotlib.org/3.3.4/tutorials/colors/colormaps.html#sphx-glr-tutorials-colors-colormaps-py for options.	`'gray'`
`colors`	`list`	A list of custom colors to create a colormap. Defaults to None.	`None`
`discrete`	`bool`	Whether to create a discrete colorbar. Defaults to False.	`False`
`label`	`str`	Label for the colorbar. Defaults to None.	`None`
`width`	`float`	The width of the colormap. Defaults to 8.0.	`8.0`
`height`	`float`	The height of the colormap. Defaults to 0.4.	`0.4`
`orientation`	`str`	The orientation of the colormap. Defaults to "horizontal".	`'horizontal'`
`vmin`	`float`	The minimum value range. Defaults to 0.	`0`
`vmax`	`float`	The maximum value range. Defaults to 1.0.	`1.0`
`axis_off`	`bool`	Whether to turn axis off. Defaults to False.	`False`
`show_name`	`bool`	Whether to show the colormap name. Defaults to False.	`False`
`font_size`	`int`	Font size of the text. Defaults to 12.	`12`

Source code in leafmap/colormaps.py

def plot_colormap(
    cmap: Optional[str] = "gray",
    colors: Optional[List] = None,
    discrete: Optional[bool] = False,
    label: Optional[str] = None,
    width: Optional[float] = 8.0,
    height: Optional[float] = 0.4,
    orientation: Optional[str] = "horizontal",
    vmin: Optional[float] = 0,
    vmax: Optional[float] = 1.0,
    axis_off: Optional[bool] = False,
    show_name: Optional[bool] = False,
    font_size: Optional[int] = 12,
    **kwargs
) -> None:
    """Plot a matplotlib colormap.

    Args:
        cmap (str, optional): Matplotlib colormap. Defaults to "gray". See https://matplotlib.org/3.3.4/tutorials/colors/colormaps.html#sphx-glr-tutorials-colors-colormaps-py for options.
        colors (list, optional): A list of custom colors to create a colormap. Defaults to None.
        discrete (bool, optional): Whether to create a discrete colorbar. Defaults to False.
        label (str, optional): Label for the colorbar. Defaults to None.
        width (float, optional): The width of the colormap. Defaults to 8.0.
        height (float, optional): The height of the colormap. Defaults to 0.4.
        orientation (str, optional): The orientation of the colormap. Defaults to "horizontal".
        vmin (float, optional): The minimum value range. Defaults to 0.
        vmax (float, optional): The maximum value range. Defaults to 1.0.
        axis_off (bool, optional): Whether to turn axis off. Defaults to False.
        show_name (bool, optional): Whether to show the colormap name. Defaults to False.
        font_size (int, optional): Font size of the text. Defaults to 12.
    """
    fig, ax = plt.subplots(figsize=(width, height))

    if colors is not None and (isinstance(colors, list) or isinstance(colors, tuple)):
        hexcodes = to_hex_colors(list(colors))
        if discrete:
            col_map = mpl.colors.ListedColormap(hexcodes)
            vals = np.linspace(vmin, vmax, col_map.N + 1)
            norm = mpl.colors.BoundaryNorm(vals, col_map.N)

        else:
            col_map = mpl.colors.LinearSegmentedColormap.from_list(
                "custom", hexcodes, N=256
            )
            norm = mpl.colors.Normalize(vmin=vmin, vmax=vmax)
    else:
        col_map = mpl.colormaps[cmap]
        norm = mpl.colors.Normalize(vmin=vmin, vmax=vmax)

    cb = mpl.colorbar.ColorbarBase(
        ax, norm=norm, cmap=col_map, orientation=orientation, **kwargs
    )

    if label is not None and isinstance(label, str):
        cb.set_label(label, fontsize=font_size)

    if axis_off:
        ax.set_axis_off()
    ax.tick_params(labelsize=font_size)

    if show_name:
        pos = list(ax.get_position().bounds)
        x_text = pos[0] - 0.01
        y_text = pos[1] + pos[3] / 2.0
        fig.text(x_text, y_text, cmap, va="center", ha="right", fontsize=font_size)

    plt.show()

`plot_colormaps(width=8.0, height=0.4, return_fig=False, **kwargs)` ¶

Plot all available colormaps.

Parameters:

Name	Type	Description	Default
`width`	`float`	Width of the colormap. Defaults to 8.0.	`8.0`
`height`	`float`	Height of the colormap. Defaults to 0.4.	`0.4`
`return_fig`	`bool`	Whether to return the figure. Defaults to False.	`False`

Source code in leafmap/colormaps.py

def plot_colormaps(
    width: Optional[float] = 8.0,
    height: Optional[float] = 0.4,
    return_fig: Optional[bool] = False,
    **kwargs
) -> None:
    """Plot all available colormaps.

    Args:
        width (float, optional): Width of the colormap. Defaults to 8.0.
        height (float, optional): Height of the colormap. Defaults to 0.4.
        return_fig (bool, optional): Whether to return the figure. Defaults to False.
    """
    cmap_list = list_colormaps()
    nrows = len(cmap_list)
    fig, axes = plt.subplots(nrows=nrows, figsize=(width, height * nrows))
    fig.subplots_adjust(top=0.95, bottom=0.01, left=0.2, right=0.99)

    gradient = np.linspace(0, 1, 256)
    gradient = np.vstack((gradient, gradient))

    for ax, name in zip(axes, cmap_list):
        ax.imshow(gradient, aspect="auto", cmap=mpl.colormaps[name])
        ax.set_axis_off()
        pos = list(ax.get_position().bounds)
        x_text = pos[0] - 0.01
        y_text = pos[1] + pos[3] / 2.0
        fig.text(x_text, y_text, name, va="center", ha="right", fontsize=12)

    # Turn off *all* ticks & spines, not just the ones with colormaps.
    for ax in axes:
        ax.set_axis_off()

    if return_fig:
        return fig
    else:
        plt.show()

colormaps module¶

create_colormap(cmap='gray', colors=None, discrete=False, label=None, width=8.0, height=0.4, orientation='horizontal', vmin=0, vmax=1.0, axis_off=False, show_name=False, font_size=12, **kwargs) ¶

get_colorbar(colors, vmin=0, vmax=1, width=6.0, height=0.4, orientation='horizontal', discrete=False) ¶

get_palette(cmap_name=None, n_class=None, hashtag=False) ¶

list_colormaps(add_extra=False, lowercase=False) ¶

plot_colormap(cmap='gray', colors=None, discrete=False, label=None, width=8.0, height=0.4, orientation='horizontal', vmin=0, vmax=1.0, axis_off=False, show_name=False, font_size=12, **kwargs) ¶

plot_colormaps(width=8.0, height=0.4, return_fig=False, **kwargs) ¶

`create_colormap(cmap='gray', colors=None, discrete=False, label=None, width=8.0, height=0.4, orientation='horizontal', vmin=0, vmax=1.0, axis_off=False, show_name=False, font_size=12, **kwargs)` ¶

`get_colorbar(colors, vmin=0, vmax=1, width=6.0, height=0.4, orientation='horizontal', discrete=False)` ¶

`get_palette(cmap_name=None, n_class=None, hashtag=False)` ¶

`list_colormaps(add_extra=False, lowercase=False)` ¶

`plot_colormap(cmap='gray', colors=None, discrete=False, label=None, width=8.0, height=0.4, orientation='horizontal', vmin=0, vmax=1.0, axis_off=False, show_name=False, font_size=12, **kwargs)` ¶

`plot_colormaps(width=8.0, height=0.4, return_fig=False, **kwargs)` ¶