matlab_class/gcmfaces_smooth/diffsmooth2D_extrap_fwd.m

function [FLD]=diffsmooth2D_extrap_fwd(fld,mskOut,eps);
%object:        extrapolate an incomplete field to create a full field, by 
%                       time-stepping a diffusion equation to near-equilibrium.
%inputs:        fld     incomplete field of interest (masked with NaN)
%               mskOut  land mask (1s and NaNs) for the full field (output)
%               eps     convergence criterium
%output:        FLD     full field

global mygrid;

dxC=mygrid.DXC; dyC=mygrid.DYC; 
rA=mygrid.RAC;

dxCsm=dxC; dyCsm=dyC;

%mask of points which values will evolve 
doStep=1*(isnan(fld));

%put first guess:
x=convert2array(mygrid.XC);
y=convert2array(mygrid.YC);
z=convert2array(fld);
m=convert2array(mskOut);
tmp1=find(~isnan(z));
tmp2=find(~isnan(m));
zz=z;
zz(tmp2) = griddata(x(tmp1),y(tmp1),z(tmp1),x(tmp2),y(tmp2),'nearest');
fld=convert2array(zz);

%put 0 first guess if needed and switch land mask:
fld(find(isnan(fld)))=0; fld=fld.*mskOut;

%scale the diffusive operator:
tmp0=dxCsm./dxC; tmp0(isnan(mskOut))=NaN; tmp00=nanmax(tmp0);
tmp0=dyCsm./dyC; tmp0(isnan(mskOut))=NaN; tmp00=max([tmp00 nanmax(tmp0)]);
smooth2D_nbt=tmp00;
smooth2D_nbt=ceil(1.1*2*smooth2D_nbt^2);

smooth2D_dt=1;
smooth2D_T=smooth2D_nbt*smooth2D_dt;
smooth2D_Kux=dxCsm.*dxCsm/smooth2D_T/2;
smooth2D_Kvy=dyCsm.*dyCsm/smooth2D_T/2;

%setup problem:
myOp.dt=1;
myOp.eps=eps;
myOp.Kux=smooth2D_Kux;
myOp.Kvy=smooth2D_Kvy;
myOp.doStep=doStep;

%time step problem:
FLD=gcmfaces_timestep(myOp,fld);


1	gforget	1.3	function [FLD]=diffsmooth2D_extrap_fwd(fld,mskOut,eps);
2			%object: extrapolate an incomplete field to create a full field, by
3			% time-stepping a diffusion equation to near-equilibrium.
4			%inputs: fld incomplete field of interest (masked with NaN)
5			% mskOut land mask (1s and NaNs) for the full field (output)
6			% eps convergence criterium
7			%output: FLD full field
8	gforget	1.1
9			global mygrid;
10
11			dxC=mygrid.DXC; dyC=mygrid.DYC;
12			rA=mygrid.RAC;
13
14			dxCsm=dxC; dyCsm=dyC;
15	gforget	1.4
16			%mask of points which values will evolve
17			doStep=1*(isnan(fld));
18	gforget	1.1
19			%put first guess:
20			x=convert2array(mygrid.XC);
21			y=convert2array(mygrid.YC);
22			z=convert2array(fld);
23			m=convert2array(mskOut);
24			tmp1=find(~isnan(z));
25			tmp2=find(~isnan(m));
26			zz=z;
27			zz(tmp2) = griddata(x(tmp1),y(tmp1),z(tmp1),x(tmp2),y(tmp2),'nearest');
28	gforget	1.2	fld=convert2array(zz);
29	gforget	1.1
30			%put 0 first guess if needed and switch land mask:
31			fld(find(isnan(fld)))=0; fld=fld.*mskOut;
32
33			%scale the diffusive operator:
34			tmp0=dxCsm./dxC; tmp0(isnan(mskOut))=NaN; tmp00=nanmax(tmp0);
35			tmp0=dyCsm./dyC; tmp0(isnan(mskOut))=NaN; tmp00=max([tmp00 nanmax(tmp0)]);
36			smooth2D_nbt=tmp00;
37			smooth2D_nbt=ceil(1.12smooth2D_nbt^2);
38
39			smooth2D_dt=1;
40			smooth2D_T=smooth2D_nbt*smooth2D_dt;
41			smooth2D_Kux=dxCsm.*dxCsm/smooth2D_T/2;
42			smooth2D_Kvy=dyCsm.*dyCsm/smooth2D_T/2;
43
44	gforget	1.4	%setup problem:
45			myOp.dt=1;
46			myOp.eps=eps;
47			myOp.Kux=smooth2D_Kux;
48			myOp.Kvy=smooth2D_Kvy;
49			myOp.doStep=doStep;
50	gforget	1.1
51	gforget	1.4	%time step problem:
52			FLD=gcmfaces_timestep(myOp,fld);
53	gforget	1.1
54