How to control output of a function ?

I have written a function for spherical harmonics in which I want to control the ' Plotting area ' in such a way that, when we call the function into a variable, (i.e, lets say variable X= Plt( 10,30)*) I don't wanna show the plotting part. Otherwise (i.e, if the function _ Plt(10,30)* calling in a command window or somewhere in any other scripts, the plotting part of the function should run/ show the plots. The code has given below. (I have also attached the Plt.m* file with this.) Please give me an idea/ answer.... Thanks in advance.!

    function [ P_bar ] = Plt( Degree_or_Order, Theta_In_Degree )
      %%Content 
%---------------------------------Plotting of Data--------------------------------

   if grid_legth>1  % Works if ''theta'' is a grid of angles.

        r=0;
        for m=0:M
            figure;                                width=1;
              for L=r:L_max
                  PP=reshape(P_bar(L+1,m+1,1:grid_legth),1,grid_legth);
                  plot(T,PP,'linewidth',(1+(width/10)),'Color',rand(1,3)); 
                  hold on; grid on;             width=width+1;       
              end
                 title(['Plote of P_(_:_,_' num2str(m) '_)']);
                 xlabel('Co-Latitude[Degree]');
                 [Lidx,Midx] = ndgrid(r:L_max,m);
                 legends = cellstr(num2str([Lidx(:),Midx(:)],'L = %d, M = %d'));
                 legend(legends,'Location','NorthEastOutside');            
              r=r+1;
        end       
        figure; 
            PP=reshape(P_bar(L_max+1,M+1,1:grid_legth),1,grid_legth);
            plot(T,PP,'linewidth',2);                grid on; 
            xlabel('Co-Latitude[Degree]');
            title(['Plote of P(' num2str(L_max) ',' num2str(M) ')']); 

   elseif grid_legth==1  % Works for a perticular co-latitude.

        figure;
        for m=0:M
            a = linspace(10,150,L_max+1);
            scatter(0:L_max,P_bar(:,m+1),a,'filled');  
            hold on; grid on; 
        end
            [Midx] = ndgrid(0:M);
            legends = cellstr(num2str([Midx(:)],' M = %d'));
            legend(legends,'Location','NorthEastOutside');
            title(['Scatter of P(' num2str(L_max) ',' num2str(m) ') with theta= ' num2str(T) ' degree']);
            xlabel('Degree of Legendre Function (0 to L_m_a_x)');
   end    

end

Answer 1

[Walter Roberson]

nargout is 0 if there is no assignment implied in the way it was called

[Jacky Jo]

Yes.... It's working... Thank you very much, Walter Roberson!