How would you upscale gridded data?

Question

andrew joros am 5 Apr. 2012

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https://de.mathworks.com/matlabcentral/answers/34658-how-would-you-upscale-gridded-data

Hi

I have a 2-d 12km dataset that I would like to convert to 32km gridded resolution. Just wondering how you would approach this? I have written a for loop seen here: http://pastebin.com/6iq97HyR, but it takes way too long to complete(~1.5 weeks)

Thanks

for lo = 20:91
    for la = 1:101
        tmplat = latsmall(lo,la);
        tmplon = lonsmall(lo,la);
        f = find(min((latNLDAS(:)-tmplat).^2+(lonNLDAS(:)-tmplon).^2)==((latNLDAS(:)-tmplat).^2+(lonNLDAS(:)-tmplon).^2));
        y = floor(f/224)+1;
        y = y(1);
        x = mod(f,224);
        x = x(1);
        for yr = 1:15
            tic;
            for mo = 1:5
                fprintf(' lo %d la %d yr %d mo %d \n',lo,la,yr+1994,mo);
                for dy=1:31
                    pptNL(yr,lo,la,mo,dy)= nan;
                    if (mo == 2 || 5) && (dy==31)
                        continue;
                    else
                        date = [num2str(mo+4) '/' num2str(dy) '/' num2str(1994+yr)];
                        if (x-2<=0) || (y-2<=0) || (x-2>224) || (y-2>464) ||...,
                                (x-1<=0) || (y-1<=0) || (x-1>224) || (y-1>464) ||...,
                                (x-0<=0) || (y-0<=0) || (x-0>224) || (y-0>464) ||...,
                                (x+1<=0) || (y+1<=0) || (x+1>224) || (y+1>464) ||...,
                                (x+2<=0) || (y+2<=0) || (x+2>224) || (y+2>464)
                            continue
                        else
                            pptNL(yr,lo,la,mo,dy)= nanmean...,
                                ([PRECIP(x-2,y+2,datevec2doy(datevec(date)))...,
                                PRECIP(x-2,y+1,datevec2doy(datevec(date)))...,
                                PRECIP(x-2,y+0,datevec2doy(datevec(date)))...,
                                PRECIP(x-2,y-1,datevec2doy(datevec(date)))...,
                                PRECIP(x-2,y-2,datevec2doy(datevec(date)))...,
                                PRECIP(x-1,y+2,datevec2doy(datevec(date)))...,
                                PRECIP(x-1,y+1,datevec2doy(datevec(date)))...,
                                PRECIP(x-1,y+0,datevec2doy(datevec(date)))...,
                                PRECIP(x-1,y-1,datevec2doy(datevec(date)))...,
                                PRECIP(x-1,y-2,datevec2doy(datevec(date)))...,
                                PRECIP(x,y+2,datevec2doy(datevec(date)))...,
                                PRECIP(x,y+1,datevec2doy(datevec(date)))...,
                                PRECIP(x,y,datevec2doy(datevec(date)))...,
                                PRECIP(x,y-1,datevec2doy(datevec(date)))...,
                                PRECIP(x,y-2,datevec2doy(datevec(date)))...,
                                PRECIP(x+1,y+2,datevec2doy(datevec(date)))...,
                                PRECIP(x+1,y+1,datevec2doy(datevec(date)))...,
                                PRECIP(x+1,y+0,datevec2doy(datevec(date)))...,
                                PRECIP(x+1,y-1,datevec2doy(datevec(date)))...,
                                PRECIP(x+1,y-2,datevec2doy(datevec(date)))...,
                                PRECIP(x+2,y+2,datevec2doy(datevec(date)))...,
                                PRECIP(x+2,y+1,datevec2doy(datevec(date)))...,
                                PRECIP(x+2,y+0,datevec2doy(datevec(date)))...,
                                PRECIP(x+2,y-1,datevec2doy(datevec(date)))...,
                                PRECIP(x+2,y-2,datevec2doy(datevec(date)))...,
                                ]);
                        end
                    end
                end
            end
        end
    end
end