Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
hi, I have a problem with the contour routine in pv-wave. I would like to directly access the contour-paths that the contour program calculates. E.G. The comand contour,x,levels=[0],PATH_FILENAME="cont", /FOLLOW is suposed to write the 0-contours of x in the file "cont". Any indiviudal contour-data-set starts with a header of the structure h = {CONTOUR_HEADER, TYPE : 0B, HIGH : 0B, LEVEL : 0, $ NUM : 0L, VALUE : 0.0} followed by NUM floating coordinate pairs. When I try to read the file cont, I get junk. The main problem is that h.num appears to contain a fantasie number instead of the number of contour points. A minor problem is that any closed contour-path begins with the coordinates (0,0). The following sequence of comands ilustrates the problem: x = shift(dist(20),10,10)^2-16 contour,x,levels=[0],PATH_FILENAME="cont", /FOLLOW, /noerase h = {CONTOUR_HEADER, TYPE : 0B, HIGH : 0B, LEVEL : 0, $ NUM : 0L, VALUE : 0.0} y = fltarr(2,34) openr,1,"cont" readu,1,h readu,1,y close,1 print,h plot,y(0,*),y(1,*) print,h gives "{ 1 0 0141733920768 0.00000}" while the contour-path however actualy contains only 34 but not 141733920768 entries. Is this a bug? Does anybody know how to reveal the true number of contour-path entries? Thanks a lot in advance Fred ************************************************************ ************ Fred Wolf E-Mail: fred@chaos.uni-frankfurt.de Max-Planck-Institut f. Stromungsforschung Bunsenstr. 10 Tel: 0551/5176-423 D-37073 Gottingen Fax: (49)551/5176-402 Germany ************************************************************ ************