/* addz.aml /**************************************************** /* written by Ralph Haugerud, USGS Seattle /* rhaugerud@usgs.gov /* 206-553-5542 /* last modified 7 April 1998 /* /* WARNING: THE Z VALUES ON COMBINED BATHYMETRIC-TOPOGRAPHIC /* MAPS HAVE DIFFERENT VERTICAL DATUMS (ZERO-POINTS). /* For example, at Seattle, a point in Elliot Bay with a depth /* of 10 meters (z = -10) is approximately 21.5 meters lower than /* a nearby point with an elevation of 10 meters (z = 10). The 1.5-meter /* discrepancy reflects the difference between the bathymetric /* datum (mean lower low water, at Seattle) and the topographic /* datum (NAVD for almost all USGS topography, roughly equal to /* mean sea level) AT SEATTLE. THE DIFFERENCE CHANGES WITH /* LOCATION (and time). It is a function of tidal range and local /* convention. Not all bathymetry uses MLLW as its datum. And /* the difference between NAVD and mean sea level varies with /* location and time! /* ANOTHER WARNING: THIS MACRO MAY FAIL! After running it, look /* at the modified cover in ARCEDIT and select for Z = 0 /* ARE ANY SELECTED ARCS CONTOURS? /* If so, what are their attributes? Modify the selection criteria /* below and the calculation of z values to catch these arcs. /* Rerun addz.aml. When you are happy with the results, again in /* ARCEDIT, /* Arcedit: sel z <> 0 /* Arcedit: put /* and use for input to TOPOGRID (or whatever) /**************************************************** &args cov &if [null %cov%] &then &do &type USAGE addz &stop &end additem %cov%.aat %cov%.aat z 4 6 B additem %cov%.pat %cov%.pat z 4 6 B display 0 ae ec %cov% ef arc sel major1 = 20 resel minor1 = 205 resel major4 = 24 &if [show number select] > 0 &then calc z = 0 - minor4 sel major1 = 20 resel minor1 = 205 resel major3 = 24 &if [show number select] > 0 &then calc z = 0 - minor3 sel major1 = 20 resel minor1 = 205 resel major2 = 24 &if [show number select] > 0 &then calc z = 0 - minor2 sel major1 = 20 resel minor1 = 200 &if [show number select] > 0 &then calc z = minor2 resel major3 = 24 &if [show number select] > 0 &then calc z = minor3 sel major1 = 20 resel minor1 = 201 resel major2 = 24 &if [show number select] > 0 &then calc z = minor2 ef point sel major2 = 24 &if [show number select] > 0 &then calc z = minor2 save quit /* arcedit &return