"some elements in return list undefined" but only when executed from a script

[Jeff]

When I run the following script, I get the error "warning: plotFPU: some elements in list of return values are undefined". However, I can assure you that plotFPU is valung both return values (I don't need the second one for this script). However, if I type the plotFPU command by hand, without the trailing semicolon (;), it works (though I get a lot of output I don't want). Why doesn't this work with a semicolon on the end?

I even tried (temporarily) rewriting it so that plotFPU only passes back one variable, h, and makeGraphs only receives one variable? Still no luck.

makeGraphs.m

clear; more off;

for p = 4:7

  tic; initFPU_2D; toc;

  tStep = 0;

  src   = '/raid/fpuData/';

  tgt   = '/raid/fpuData/graphs/';

  ftype = '.U.csv';

  for beta = 0:100:2000

    for pTol = 8

      % Read the solution file

      fn = sprintf('N=%03dx%03d_Beta=%04d_tol=1e-%02d_t=%07d', N, N, beta, pTol, tStep);

      fprintf('Loading %s:\t', [fn ftype]);

      tic; u1 = csvread([src fn ftype]); toc;

      % Transform to fourier space

      [U,Udot,W,Wdot] = xformFPU(u1, F);

      % Plot it

      fn = sprintf('%s%s', tgt, fn);

      fprintf('Creating flie: %s\t', fn);

      [h,dummy]=plotFPU(N, 'Fixed', beta, D, W, Wdot);

      print (h, fn, "-dpdf"); toc;

    end

  end

end

plotFPU.m (5th and 6th lines set return values)

function [h, Hn_f] = plotFPU(N, boundary, beta, D, W, Wdot)

  repD = repmat(D,[size(W,1),1]);

  Pn_f = (W.^2).*(repD./N);

  Qn_f = (Wdot.^2)./N;

  Hn_f = Pn_f + Qn_f;

  h=figure(2);

  clf; hold on;

  col=1;

  plot(Hn_f(:,col),'b-');

  if N/2 >= 4, plot(Hn_f(:,col+2),'r-'); end

  if N/2 >= 6, plot(Hn_f(:,col+4),'g-'); end

  if N/2 >= 8, plot(Hn_f(:,col+6),'k-'); end

  axis tight;

  strTitle = 'Energy per Mode (N=%d, Beta=%.d, %s BC)';

  strTitle=sprintf(strTitle, N, beta, boundary);

  title(strTitle,'FontSize',12);

  xlabel('Time');

  ylabel('Energy');

  hold off;

end