read/sheetij

creates a quad mesh from an elevation file using syntax similar to avs type .fld header file. Note the input file is assumed to contain elevation values and are read as Z(i,j) into the cmo attribute “zic”. For node attribute values of f(i,j), use addatt and copyatt as shown in the examples below.

FORMAT:

read /sheetij/ file_name /nx,ny/minx,miny/dx,dy [options]

read /sheetij/ file_name /nx,ny/minx,miny/dx,dy/ skip n / [options]

read /sheetij/ file_name /nx,ny/minx,miny/dx,dy/istart,jstart,istop,jstop/[options]

read /sheetij/ file_name/-header-/[options]

Argument | Description
————————— | —————————————————— nx | columns in x direction ny | rows in y direction min, miny | location of lower left corner xinc, yinc | cell size in x and y direction -header- | keyword meaning read nx, ny,miny,xinc,yinc,from file skip n | skip n number of header lines istart,istop,jstart,jstop | gives indices of ij subset   ————————— ——————————————————

Option | Description ————————— | ————————————————————— ascii or binary | file-type (default-ascii) center | assume elevation at cell center (default = lower left corner) connect or points | connect causes quad grid to be formed and is default. points keeps data as points only. float or double | size of data (default = float) xflip or yflip | reflect along x or y axis (default = no reflection)  ————————— —————————————————————

EXAMPLES:

 for data file with header - test_hdr.dat, showing nx, ny, min x, min y, dx, dy

           #  5    
           #  4    
           #         0.0000000  
           #         0.0000000  
           #         5.000000   
           #         5.000000   
           #

        to read elevations using information in the file header
        cmo create cmohdr
        read sheetij test\_hdr.dat / -header- / ascii

        to subset read ascii file with header and subset from i=2,5
 and j=3,4

          read sheetij test\_hdr.dat / -header- / 2,5, 3,4 / ascii

        for binary files with no headers where nx=5, ny=4,
 minx=miny=0., xinc=yinc=5.

          read sheetij test.bin /5,4 /0.0,0.0 / 5.0,5.0 / binary

        to flip along the x-axis
          read sheetij test.bin /5,4 /0.0,0.0 / 5.0,5.0 / xflip,
 binary

        read temperature values from file instead of elevation
         cmo create cmot
         read sheetij temp.dat / 150,183 /1602850.,1727950. / &
         500.0,500.0 / skip 6
         cmo / addatt / cmot / tempval / VDOUBLE / scalar / nnodes
         cmo / copyatt / cmot / cmot / tempval / zic
         cmo / setatt / cmot / zic / 0.

TEST EXAMPLES:

Test file for sheetij: LaGriT_input00

Test data for sheetij: test_data

* read ascii elevations into quad sheet
cmo create cmo1
read sheetij test_data /5,4 /0.0,0.0 &
/ 5.0,5.0 / ascii

* read ascii elevations and flip x
cmo create cmo1
read sheetij test_data /5,4 /0.0,0.0 &
/ 5.0,5.0 / xflip, ascii

* read binary elevations and subset along ij
cmo create cmo1a
read sheetij qbog50_l.float /31,21/ 0. 0./ 50.0,50.0 &
/10,25 1,10/ binary / float
* combine grids for viewing
math/sub/cmo1a/zic/1,0,0/cmo1a/zic/500.
addmesh merge cmov cmo1 cmo1a
dump gmv view_binsurf_subset.gmv cmov