c	This program reads data output from grid_ctd.x or grid_sd2.x 
c    and output either a decimated grid or interpolation to 
c    user-specified latitude or longitude coordinates from the
c    original distance coordinates.
c   Salim Odero 9/96
c
c
c
	program grid_interp 
	parameter (ngx=1000,ngy=700)	
c  matrix program 
	integer nx,ny
	real xres,yres,xleft,xright,ytop,ybot
	real grid(ngy,ngx), grerror(ngy,ngx)

c  initialize variables
	data nx, ny/2*0/
	data xres,yres,xleft,xright,ytop,ybot/6*0.0/
c
c  call the main subroutines of the program	
c
	call read_matrix(grid,grerror,nx,ny,xres,yres,xleft,xright,ytop,ybot)
c
c the following decimates the grid vertically
c it replaces the old grid and grerror with the decimated values
c  and resets ny, yres and ybot
       call decimate_matrix(grid,grerror,nx,ny,xres,yres,xleft,
     1        xright,ytop,ybot)
c
c the following interpolates matrix to degrees lat or long
       call interpolate_matrix(grid,grerror,nx,ny,xres,yres,xleft,
     1     xright,ytop,ybot)
c
c write matrix in binary, ascii or netcdf format
       call save_matrix(grid,grerror,nx,ny,xres,yres,xleft,
     1       xright,ytop,ybot)
c
	stop
	end