It could be something like this:
% Assume table (T) with these variables: year, region, type_of_patents, regional_share
% Find the total of regional share for each region by year by type of patents.
u_type_of_patents = unique(T.type_of_patents)
u_year = unique(T.year)
u_region = unique(T.region)
u_year = unique(T.year)
for ip = 1:length(u_type_of_patents)
for iy = 1:length(u_year)
for ir = 1:length(u_region)
totalshare=(sum(T.regional_share(...
T.type_of_patents==u_type_of_patents(ip) & ...
T.year==u_year(iy) & ...
T.region==u_region(ir) )));
%fprintf(...)
end
end
end
