% compute yCSR = A*x with A in CSR format
function yCSR = SpMV_CSR(valACSR,colindexACSR,rowbeginACSR,x);
yCSR = zeros(length(rowbeginACSR)-1,1);  % allocate space for answer
for i = 1:length(rowbeginACSR)-1,
    tmp = 0;
    for j=rowbeginACSR(i):rowbeginACSR(i+1)-1,
        tmp = tmp + valACSR(j)*x(colindexACSR(j));
    end
    yCSR(i) = tmp;
end