NAME xm_origin - Origin File format for the xmap8 program SYNOPSIS xm_origin - Input File Format DESCRIPTION The origin file is required for starting xmap8. It describes the layout and geometry of the intended study area. It also describes the map projection used. There are two styles of origin: terse and verbose. FORMAT Terse Origin File: This is a simple 3 line file that contains the origin and a few other important matters concerning the scale of the plot. Example: 0 1 52 52 10 2.0 33.0 47.0 0.0 -117.0 10.0 0. The first integer numbers refer to the kind of origin file being read. 0,1 = standard (tomography) style, i.e an origin Lat-Lon pair and then number of x,y blocks (in KM) to the east and to the north of the origin. The origin is always the lower left-hand corner (South-West) of the map. 2 indicates a LAT_LON origin, i.e. the second and third lines consist of Lat-Lon pairs that define the boundaries of the map instead of the origin. (e.g. minlat maxlat minlon maxlon ) The second integer indicates the kind of Map Projection. 0,1 the old version, ellipsoidal projection good for local coordinates. 2 = Albers Equal Area (spheroidal) projection 3 = Mercator Projection 4 = Miller Projection 5 = No Projection 6 = UTM-spherical 7 = UTM-ellipsoidal 8 = centered UTM spherical 9 = centered UTM ellipsoidal Grid definition: The third (52, in this case) and forth refer to the number of 'blocks' (grid divisions) in the x and y- directions respectively. The 5-th number is the number of 'blocks' in the z-direction (for use on 3D models) Use this to pre-set the MaxDepth parameter. The 6-th number is the number of km per block in the x direction. If a 7-th parameter is provided it is the dy, km/block on the y direction. (So if you like to have everything in km use 1.0) NEW (Verbose style) A more verbose but user friendly method of origin file is now available: lines that start with '#' are comments lines. E.G.: --------------- # new origin style input file: # file must start with a non-integer alpha character # order of cards is not important and spaces are allowed # between name = value type=0 proj=0 nx=30 ny=50 nz=10 dx=5.0 dy=5.0 lat=46.4 0.0 0.0 lon=-123.0 25.0 0.0 # note lon is positive east! # so longitudes in the western hemisphere should be negative # (minutes and seconds are always positive!) # also, you do not need minutes and second if have you only decimal degs # note also that comments are allowed starting with '#' # and a new parameter 'dy' is included for more flexability # proj=0 lees ellipsoidal projection # proj=1 lees ellipsoidal projection # proj=2 albers equal area # proj=3 mercator # proj=4 miller # proj=5 no projection # proj=6 UTM-spherical # proj=7 UTM-ellipsoidal # proj=8 centered UTM spherical # proj=9 centered UTM ellipsoidal --------------- Examples: ----------------------------------- Albers Equal Area Map of California: 1 2 60 64 25 18 32.0 15.0 0.0 -125.0 0.0 0.0 ---------------------------------- Washington State: 1 2 640 500 10 1.0 45.0 0.0 0.0 -125.0 0.0 0.0 --------------------------------- Japan (this is a lat-lon style origin): 2 2 70 64 1 60 29.088596 46.766563 90.627243 90.981079 -------------------------------- Southern Califonia: 0 0 64 44 1 5.000000 33.000000 43.000000 37.822266 -119.000000 12.000000 45.197754 ----------------------------------- SEE ALSO xmap8 xm_color xm_hypo xm_map xm_menu xm_origin xm_points xm_raster xm_station xm_well xm_wire xm_xsec xm_ellipse
REFERENCES see article by J. M. Lees: Lees, J. M. (1995) Xmap8: Three-dimensional GIS for geology and geophysics, Seismological Research Letters: 66, 33-37.
Prof. Jonathan M. Lees Yale Geology Dept. P.O. Box 208109 New Haven, CT 06520-8109 (203)432-6947 lees@love.geology.yale.edu