add_contour( [ChipsId,] filename [,attributes])
add_contour( [ChipsId,] IMAGECrate [,attributes])
add_contour( [ChipsId,] data-array, x-dim, y-dim [,levels] [, trans]
[,attributes])

Description

• ChipsId - an optional ChipsId structure containing values to modify the currency state for the command.
• IMAGECrate/filename - input data, specified as a filename or an IMAGECrate ("ahelp py.crates crates")
• data-array - 1D regular, non-sparse data array containing the points to be contoured.
• x-dim - size of the x dimension of data_array
• y-dim - size of the y dimension of data_array
• levels - the number of contour levels
• trans - transform to be applied to the contoured data
• attributes - optional parameters which allow the user to configure properties though a structure, list, or attribute string.

The add_contour command creates a contour whose attributes are specified by user preferences or in an attribute list. The new contour becomes current by default; providing a ChipsId overrides the currency state.

The data-array is a one-dimensional array of data points to be contoured. The array is treated as a 2D array by using x-dim and y-dim parameters to set the x and y dimensions. If a transform is set to be applied, the data in data-array is first contoured and then the transform is applied to the contours.

Customizing the Contour

There are several attributes that control the contour characteristics. The attributes can be set to the ChIPS defaults, values provided in the add_contour command, or values from the user's preference file.

The attributes may also be modified with the set_contour command at any time; see "ahelp py.chips set_contour" and "ahelp py.chips setget" for more information.

The attributes associated with contours are:

Attribute	Description	Options	Default
algorithm	the contouring algorithm to be used	standard|marching	standard
color	contour color	see the Color section of "ahelp py.chips chipsopt"	default
depth	Depth used for the contour object	see the Depth section of "ahelp py.chips chipsopt"	Default
interval	Indicates the delta value from one contour level to the next	Integer	10
levels	Specifies the number of levels in the contour	Non-negative integer	5
mode	Mode of the axis tickmark positioning	see the Tick Mode section of "ahelp py.chips chipsopt"	nice
stem	Stem used for contour id	Alphanumeric	ctr
style	Stipple pattern used to draw the line segment	see the Line Style section of "ahelp py.chips chipsopt"	solid
thickness	Thickness of the line	see the Thickness section of "ahelp py.chips chipsopt"	1
wcs	The name of the coordinate system to use	"logical", "physical", "world". You can also use the names of the transforms, such as "sky" and "EQPOS".	"world", if available.

chips> add_contour("img.fits")

chips> set_xaxis(["tickformat","ra"])
chips> reverse_axes(X_AXIS)
chips> set_yaxis(["tickformat","dec"])

chips> add_contour("img.fits", [10,20,30])

chips> add_contour("img.fits", ["color","green","thickness,2])

chips> add_contour("img.fits", [10,20,30],
["color","green","thickness,2])

chips> add_contour("img.fits", [10,20,30], ["wcs","logical"])

chips> img = read_file("contours.img")
chips> add_contour(img)

chips> add_contour([[1,1,1], [1,3,1], [1,1,1]], 3,3)

chips> add_contour([[1,1,1], [1,3,1], [1,1,1]],
3,3,["color","lime","style","solid"])

chips> ci = ChipsContour()
chips> ci.color = "lime"
chips> ci.style = "solid"
chips> add_contour([[1,1,1], [1,3,1], [1,1,1]], 3,3, ci)

chips> add_contour([[1,1,1], [1,3,1], [1,1,1]], 3,3, [1.1,1.5,2,2.5])
chips> set_contour(["color","lime", "style","solid"])