'
'----------------------------
'--- Creation information ---
'----------------------------
'
'Name: wfacgrid.ave
'Version: 1.0
'Date: 02/17/97
'Author: Ferdi Hellweger
'        Center for Research in Water Resources
'        The University of Texas at Austin
'        ferdi@crwr.utexas.edu
'
'Modified: 02/28/97
'          Ann Quenzer
'          Center for Research in Water Resources
'          The University of Texas at Austin
'          quenzer@mail.utexas.edu
'          1) changed the conversions to reflect project
'          2) changed the message box descriptions to reflect the script
'          3) computes an integer grid
'          4) added purpose and description
'
'---------------------------
'--- Purpose/Description ---
'---------------------------
'
'Computes the weighted flow accumulation using the flow direction grid
'and the land surface loading grid.  The resulting grid produces 
'a grid (wfacload) with the loadings to the bay in Kg/day.  
'
'----------------
'--- Get view ---
'----------------
'
theview = av.getactivedoc
'
'------------------
'--- Get themes ---
'------------------
'
thethemes = theview.getthemes
if (thethemes.count = 0) then
    msgbox.error("No themes found", "WFAC GRID")
    exit
end
if (thethemes.count = 1) then
    msgbox.error("Only one theme found", "WFAC GRID")
    exit
end
thegthemes = list.make
for each thetheme in thethemes
    if (thetheme.getclass.getclassname = "gtheme") then
        thegthemes.add(thetheme)
    end
end
if (thegthemes.count = 0) then
    msgbox.error("No grid themes found", "WFAC GRID")
    exit
end
if (thethemes.count = 1) then
    msgbox.error("Only grid one theme found", "WFAC GRID")
    exit
end
fdrtheme = msgbox.listasstring(thegthemes, "Flow direction theme", "WFAC GRID")
if (fdrtheme = nil) then
    exit
end
ldtheme = msgbox.listasstring(thegthemes, "Load theme", "WFAC GRID")
if (ldtheme = nil) then
    exit
end
'
'-----------------
'--- Calculate ---
'-----------------
'
fdrgrid = fdrtheme.getgrid
ldgrid = ldtheme.getgrid
'
cellsize = number.makenull
dummmy = grid.getanalysiscellsize(cellsize)
extent = rect.makenull
dummy = grid.getanalysisextent(extent)
'
facgrid = (fdrgrid.flowaccumulation(ldgrid)).int
facfilename = av.getproject.makefilename("facgrid", "")
facgrid.savedataset("/home1/alpha62/maidment/ex7/wfacgrid".asfilename)
facgtheme = gtheme.make(facgrid)
theview.addtheme(facgtheme)
facgtheme.setvisible(true)
'
'final message to user
'
message = "Accumulated load grid calculated."
msgbox.info(message,"WFAC GRID")
'
'-----------
'--- End ---
'-----------
'