# CoordinateHelper¶

class astropy.visualization.wcsaxes.CoordinateHelper(parent_axes=None, parent_map=None, transform=None, coord_index=None, coord_type='scalar', coord_unit=None, coord_wrap=None, frame=None, format_unit=None)[source]

Bases: object

Helper class to control one of the coordinates in the WCSAxes.

Parameters: parent_axes : WCSAxes The axes the coordinate helper belongs to. parent_map : CoordinatesMap The CoordinatesMap object this coordinate belongs to. transform : Transform The transform corresponding to this coordinate system. coord_index : int The index of this coordinate in the CoordinatesMap. coord_type : {‘longitude’, ‘latitude’, ‘scalar’} The type of this coordinate, which is used to determine the wrapping and boundary behavior of coordinates. Longitudes wrap at coord_wrap, latitudes have to be in the range -90 to 90, and scalars are unbounded and do not wrap. coord_unit : Unit The unit that this coordinate is in given the output of transform. format_unit : Unit, optional The unit to use to display the coordinates. coord_wrap : float The angle at which the longitude wraps (defaults to 360) frame : BaseFrame The frame of the WCSAxes.

Attributes Summary

Methods Summary

 display_minor_ticks(display_minor_ticks) Display minor ticks for this coordinate. format_coord(value[, format]) Given the value of a coordinate, will format it according to the format of the formatter_locator. get_axislabel() Get the text for the axis label get_axislabel_visibility_rule(rule) Get the rule used to determine when the axis label is drawn. get_minor_frequency() grid([draw_grid, grid_type]) Plot grid lines for this coordinate. set_axislabel(text[, minpad]) Set the text and optionally visual properties for the axis label. set_axislabel_position(position) Set where axis labels should appear set_axislabel_visibility_rule(rule) Set the rule used to determine when the axis label is drawn. set_coord_type(coord_type[, coord_wrap]) Set the coordinate type for the axis. set_format_unit(unit[, decimal, …]) Set the unit for the major tick labels. set_major_formatter(formatter) Set the formatter to use for the major tick labels. set_minor_frequency(frequency) Set the frequency of minor ticks per major ticks. set_separator(separator) Set the separator to use for the angle major tick labels. set_ticklabel([color, size, pad, …]) Set the visual properties for the tick labels. set_ticklabel_position(position) Set where tick labels should appear set_ticklabel_visible(visible) Set whether the tick labels are visible or not. set_ticks([values, spacing, number, size, …]) Set the location and properties of the ticks. set_ticks_position(position) Set where ticks should appear set_ticks_visible(visible) Set whether ticks are visible or not. tick_params([which]) Method to set the tick and tick label parameters in the same way as the tick_params() method in Matplotlib.

Attributes Documentation

formatter
locator

Methods Documentation

display_minor_ticks(display_minor_ticks)[source]

Display minor ticks for this coordinate.

Parameters: display_minor_ticks : bool Whether or not to display minor ticks.
format_coord(value, format='auto')[source]

Given the value of a coordinate, will format it according to the format of the formatter_locator.

Parameters: value : float The value to format format : {‘auto’, ‘ascii’, ‘latex’}, optional The format to use - by default the formatting will be adjusted depending on whether Matplotlib is using LaTeX or MathTex. To get plain ASCII strings, use format=’ascii’.
get_axislabel()[source]

Get the text for the axis label

Returns: label : str The axis label
get_axislabel_visibility_rule(rule)[source]

Get the rule used to determine when the axis label is drawn.

get_minor_frequency()[source]
grid(draw_grid=True, grid_type=None, **kwargs)[source]

Plot grid lines for this coordinate.

Standard matplotlib appearance options (color, alpha, etc.) can be passed as keyword arguments.

Parameters: draw_grid : bool Whether to show the gridlines grid_type : {‘lines’, ‘contours’} Whether to plot the contours by determining the grid lines in world coordinates and then plotting them in world coordinates ('lines') or by determining the world coordinates at many positions in the image and then drawing contours ('contours'). The first is recommended for 2-d images, while for 3-d (or higher dimensional) cubes, the 'contours' option is recommended. By default, ‘lines’ is used if the transform has an inverse, otherwise ‘contours’ is used.
set_axislabel(text, minpad=1, **kwargs)[source]

Set the text and optionally visual properties for the axis label.

Parameters: text : str The axis label text. minpad : float, optional The padding for the label in terms of axis label font size. kwargs Keywords are passed to matplotlib.text.Text. These can include keywords to set the color, size, weight, and other text properties.
set_axislabel_position(position)[source]

Set where axis labels should appear

Parameters: position : str The axes on which the axis label for this coordinate should appear. Should be a string containing zero or more of 'b', 't', 'l', 'r'. For example, 'lb' will lead the axis label to be shown on the left and bottom axis.
set_axislabel_visibility_rule(rule)[source]

Set the rule used to determine when the axis label is drawn.

Parameters: rule : str If the rule is ‘always’ axis labels will always be drawn on the axis. If the rule is ‘ticks’ the label will only be drawn if ticks were drawn on that axis. If the rule is ‘labels’ the axis label will only be drawn if tick labels were drawn on that axis.
set_coord_type(coord_type, coord_wrap=None)[source]

Set the coordinate type for the axis.

Parameters: coord_type : str One of ‘longitude’, ‘latitude’ or ‘scalar’ coord_wrap : float, optional The value to wrap at for angular coordinates
set_format_unit(unit, decimal=None, show_decimal_unit=True)[source]

Set the unit for the major tick labels.

Parameters: unit : class:Unit The unit to which the tick labels should be converted to. decimal : bool, optional Whether to use decimal formatting. By default this is False for degrees or hours (which therefore use sexagesimal formatting) and True for all other units. show_decimal_unit : bool, optional Whether to include units when in decimal mode.
set_major_formatter(formatter)[source]

Set the formatter to use for the major tick labels.

Parameters: formatter : str or Formatter The format or formatter to use.
set_minor_frequency(frequency)[source]

Set the frequency of minor ticks per major ticks.

Parameters: frequency : int The number of minor ticks per major ticks.
set_separator(separator)[source]

Set the separator to use for the angle major tick labels.

Parameters: separator : str or tuple or None The separator between numbers in sexagesimal representation. Can be either a string or a tuple (or None for default).
set_ticklabel(color=None, size=None, pad=None, exclude_overlapping=None, **kwargs)[source]

Set the visual properties for the tick labels.

Parameters: size : float, optional The size of the ticks labels in points color : str or tuple, optional A valid Matplotlib color for the tick labels pad : float, optional Distance in points between tick and label. exclude_overlapping : bool, optional Whether to exclude tick labels that overlap over each other. kwargs Other keyword arguments are passed to matplotlib.text.Text.
set_ticklabel_position(position)[source]

Set where tick labels should appear

Parameters: position : str The axes on which the tick labels for this coordinate should appear. Should be a string containing zero or more of 'b', 't', 'l', 'r'. For example, 'lb' will lead the tick labels to be shown on the left and bottom axis.
set_ticklabel_visible(visible)[source]

Set whether the tick labels are visible or not.

Parameters: visible : bool The visibility of ticks. Setting as False will hide this coordinate’s tick labels.
set_ticks(values=None, spacing=None, number=None, size=None, width=None, color=None, alpha=None, direction=None, exclude_overlapping=None)[source]

Set the location and properties of the ticks.

At most one of the options from values, spacing, or number can be specified.

Parameters: values : iterable, optional The coordinate values at which to show the ticks. spacing : float, optional The spacing between ticks. number : float, optional The approximate number of ticks shown. size : float, optional The length of the ticks in points color : str or tuple, optional A valid Matplotlib color for the ticks alpha : float, optional The alpha value (transparency) for the ticks. direction : {‘in’,’out’}, optional Whether the ticks should point inwards or outwards.
set_ticks_position(position)[source]

Set where ticks should appear

Parameters: position : str The axes on which the ticks for this coordinate should appear. Should be a string containing zero or more of 'b', 't', 'l', 'r'. For example, 'lb' will lead the ticks to be shown on the left and bottom axis.
set_ticks_visible(visible)[source]

Set whether ticks are visible or not.

Parameters: visible : bool The visibility of ticks. Setting as False will hide ticks along this coordinate.
tick_params(which='both', **kwargs)[source]

Method to set the tick and tick label parameters in the same way as the tick_params() method in Matplotlib.

This is provided for convenience, but the recommended API is to use set_ticks(), set_ticklabel(), set_ticks_position(), set_ticklabel_position(), and grid().

Parameters: which : {‘both’, ‘major’, ‘minor’}, optional Which ticks to apply the settings to. By default, setting are applied to both major and minor ticks. Note that if 'minor' is specified, only the length of the ticks can be set currently. direction : {‘in’, ‘out’}, optional Puts ticks inside the axes, or outside the axes. length : float, optional Tick length in points. width : float, optional Tick width in points. color : color, optional Tick color (accepts any valid Matplotlib color) pad : float, optional Distance in points between tick and label. labelsize : float or str, optional Tick label font size in points or as a string (e.g., ‘large’). labelcolor : color, optional Tick label color (accepts any valid Matplotlib color) colors : color, optional Changes the tick color and the label color to the same value (accepts any valid Matplotlib color). bottom, top, left, right : bool, optional Where to draw the ticks. Note that this will not work correctly if the frame is not rectangular. labelbottom, labeltop, labelleft, labelright : bool, optional Where to draw the tick labels. Note that this will not work correctly if the frame is not rectangular. grid_color : color, optional The color of the grid lines (accepts any valid Matplotlib color). grid_alpha : float, optional Transparency of grid lines: 0 (transparent) to 1 (opaque). grid_linewidth : float, optional Width of grid lines in points. grid_linestyle : string, optional The style of the grid lines (accepts any valid Matplotlib line style).