% agricultural data on 24,473 zip code areas% land usage and animal inventories

% variables are:% col1 = latitude centroid% col2 = longitude centroid% col3 = zip code% col4 = state code, 1 to 48 alphabetical order% col5 = acres harvested, total farms% col6 = acres in Conservation Reserve or Wetlands Reserve Programs total farms% col7 = acres of Cropland idle, total farms% col8 = pasture, Cropland used for pasture or grazing total farms% col9 = rangeland, Pasture and rangeland other than cropland or woodland pastured total farms% col10 = woodland, Total woodland total farms% col11 = soilimprove, Cropland in cover crops legumes and soil improvement% grasses not harvested and not pastured total farms% col12 = failed, Cropland on which all crops failed total farms% col13 = fallow, Cropland in cultivated summer fallow total farms% col14 = otherland, All other land total farms% col15 = farms, all farms% col16 = farms_small, 1 to 49 acres% col17 = farms_medium, 50 to 999 acres% col18 = farms_large, 1000 acres or more% col19 = beef_cows, Beef cow inventory total farms% col20 = milk_cows, Milk cow inventory total farms% col21 = hogs_pigs, Hogs and pigs inventory total farms% col22 = sheep_lambs, Sheep and lambs inventory total farms% col23 = hens_pullets, Hens & pullets laying age inventory total farms% col24 = horses_ponies, Horses and ponies of all ages inventory total farms% col25 = owner, Full owners% col26 = pop, total zip-code area population% col27 = rural_pop, population census classified as rural% col28 = farm_pop, population census classified as farm

load agriculture.data;

vnames = strvcat('harvested','constant','conservation','idle','pasture','rangeland', ...'woodland','soilimprove','failed','fallow','otherland','farms','beef_cows','milk_cows', ...'hogs_pigs','sheep_lambs','hens_pullets','horses_ponies','owner','rural_pop','farm_pop');

latt = agriculture(:,1);long = agriculture(:,2);zip = agriculture(:,3);st_code = agriculture(:,4);

xdata = [agriculture(:,5:15) agriculture(:,19:end-4) agriculture(:,end-2:end)];% pitches farms_small, farms_medium, farms_large and poptmp = xdata(:,1:10);acres = sum(tmp');total_acres = acres';

% find non-zero total acres zip-code areasnzip = find(total_acres > 0);dat = xdata(nzip,:);

y = log(dat(:,1)+1); % acres harvested, add unity to avoid log(0)n = length(y);

xtmp = dat(:,2:end);xmat = log(xtmp + ones(size(xtmp))); % add unity to avoid log(0)

x = [ones(n,1) xmat ];

[nobs nvars] = size(x);

result = ols(y,x);prt(result,vnames);