function ri = planckmv( v,t )
%  planck function for matrix of wavenumber, v (1/cm) and temp, t (K)
%  result in spectral emissive power (pi * intensity)
%  in W/(m^2.cm^-1)
%  from
%  http://pds-atmospheres.nmsu.edu/education_and_outreach/encyclopedia/planck_function.htm

[vv tt]= meshgrid(v,t);
ri =  3.7418e-8.*vv.^3./(exp(vv.*1.4388./tt)-1);
end