The POLAR_CONTOUR procedure draws a contour plot from data in polar coordinates. Data can be regularly- or irregularly-gridded. All of the keyword options supported by CONTOUR are available to POLAR_CONTOUR.
This routine is written in the IDL language. Its source code can be found in the file polar_contour.pro in the lib subdirectory of the IDL distribution.
POLAR_CONTOUR, Z, Theta, R [, C_ANNOTATION=vector_of_strings] [, C_CHARSIZE=value] [, C_CHARTHICK=integer] [, C_COLORS=vector] [, C_LINESTYLE=vector] [, /FILL | , CELL_FILL [, C_ORIENTATION=degrees] [, C_SPACING=value]] [, C_THICK=vector] [, /CLOSED] [, /IRREGULAR] [, LEVELS=vector | NLEVELS=integer{1 to 29}] [, MAX_VALUE=value] [, MIN_VALUE=value] [, /OVERPLOT] [, /PATH_DATA_COORDS | ,TRIANGULATION=variable] [, /XLOG] [, /YLOG] [, /ZAXIS] [, SHOW_TRIANGULATION=color_index]
The data values to be contoured. If the data is regularly gridded, Z must have the dimensions (N_ELEMENTS(Theta), N_ELEMENTS(R). Note that the ordering of the elements in the array Z is opposite that used by the POLAR_SURFACE routine.
A vector of angles in radians. For regularly-gridded data, Theta must have the same number of elements as the first dimension of Z. For a scattered grid, Theta must have the same number of elements as Z.
A vector of radius values. For regularly-gridded data, R must have the same number of elements as the second dimension of Z. For a scattered grid, R must have the same number of elements as Z.
POLAR_CONTOUR accepts all of the keywords accepted by the CONTOUR routine except C_LABELS, DOWNHILL, FOLLOW, PATH_FILENAME, PATH_INFO, and PATH_XY. See CONTOUR. In addition, there is one unique keyword:
Set this keyword to a color index to be used in overplotting the triangulation between datapoints.
This example uses POLAR_CONTOUR with regularly-gridded data:
;Handle TrueColor displays: DEVICE, DECOMPOSED=0 ;Load color table TEK_COLOR nr = 12 ; number of radii nt = 18 ; number of Thetas ; Create a vector of radii: r = FINDGEN(nr)/(nr-1) ; Create a vector of Thetas: theta = 2*!PI * FINDGEN(nt)/(nt-1) ; Create some data values to be contoured: z = COS(theta*3) # (r-0.5)^2 ; Create the polar contour plot: POLAR_CONTOUR, z, theta, r, /FILL, c_color=[2, 3, 4, 5]
Introduced: 4.0