Contour()

Makes a contour plot on the graphics device.

CONTOUR/DRAW [/LOG] [/SQRT] values=RealArray [contours=RealArray] [ncont=Integer] [tr=RealArray] [colour=Colour] [line_type=LineStyle] [line_thickness=Real] Draw a contour plot onto a graphics device.
CONTOUR/ALTER [/LOG] [/SQRT] [values=RealArray] [contours=RealArray] [ncont=Integer] [tr=RealArray] [colour=Colour] [line_type=LineStyle] [line_thickness=Real] object=Gobject Alters a previously drawn contour plot on a graphics device.

example:

	# Produce a contour plot of 2-D data
	>> cp = Contour:Draw(my_points)

Note: By default the contour is linear. Use contours or ncont, not both.

Contour/Draw

Draws a contour plot of the data supplied. The contour plot should be drawn in a two-D window ( see Win_twod() ). The Contour() function is the simplest of the contouring functions and draws a contour from linearly gridded data or gridding specified by a transformation matrix. For contouring non-linnearly gridded data or non-gridded data use Contour_array() and Contour_function() respectively.

If no tranformation matrix is specified, the contour assumes linear gridding based on the window in which the data is being contoured.

Parameters:

/Log

Draws a logarithmic contour plot.

/Sqrt

Draws a square root contour plot.

Values (RealArray)

Defines the cell values of the cell plot, values is a two dimensional array with sufficient data to fit the grid points.

Contours (RealArray)

Sets the contours explicity by specifying the heights (in raw data values) of the countours. If this is specified, the number of contours will be taken from the data array and Ncont is ignored.

Ncont (Integer)

Draws ncont contours, by default, evenly spaced between Valmin and Valmax

Tr (RealArray)

Array defining a transformation between the i, j grid of the data array and the window coordinates. The window coordinates of the array point a[i,j] are given by:

x = tr[1] + tr[2] * i + tr[3] * j
y = tr[4] + tr[5] * i + tr[6] * j

Usually tr[3] and tr[5] are zero - unless the coordinate transformation involves a rotation or shear.

The default transformation if this parameter is not specified is to map linearly onto the window to fit the plot.

Colour (Colour)

Sets the contour plots colour.

Line_type (LineStyle)

Sets the line type of the contour plot. Such as $full, $dash, $dot_dash and $dot.

Line_thickness (Real)

Sets the contour plots line width.

RESULT = (Contour)

Returns all of the properties of the newly created contour plot.

Contour/Alter

Alters a contour plot previously drawn on a graphics device.

Parameters:

/Log

Draws a logarithmic contour plot.

/Sqrt

Draws a square root contour plot.

Values (RealArray)

Defines the cell values of the cell plot, values is a two dimensional array with sufficient data to fit the grid points.

Contours (RealArray)

Sets the contours explicity by specifying the heights (in raw data values) of the countours. If this is specified, the number of contours will be taken from the data array and Ncont is ignored.

Ncont (Integer)

Draws ncont contours, by default, evenly spaced between Valmin and Valmax

Tr (RealArray)

Array defining a transformation between the i, j grid of the data array and the window coordinates. The window coordinates of the array point a[i,j] are given by:

x = tr[1] + tr[2] * i + tr[3] * j
y = tr[4] + tr[5] * i + tr[6] * j

Usually tr[3] and tr[5] are zero - unless the coordinate transformation involves a rotation or shear.

The default transformation if this parameter is not specified is to map linearly onto the window to fit the plot.

Colour (Colour)

Sets the contour plots colour.

Line_type (LineStyle)

Sets the line type of the contour plot. Such as $full, $dash, $dot_dash and $dot.

Line_thickness (Real)

Sets the contour plots line width.

Object (Gobject)

Shows which contour plot is to be altered.

RESULT = (Contour)

Returns all of the properties of the altered contour plot.