ENH - added test script for http://bugzilla.fieldtriptoolbox.org/show…

…_bug.cgi?id=3182, no problem detected

test/test_bug3182.m

@@ -0,0 +1,44 @@
+function test_bug3182
+
+% MEM 1500mb
+% WALLTIME 00:10:00
+
+% TEST test_bug3182
+% TEST ft_freqanalysis ft_freqdescriptives
+
+%% generate some data
+
+data          = [];
+for i=1:10
+  data.trial{i} = randn(2,1000);
+  data.time{i}  = (1:1000)/1000;
+end
+data.label    = {'chan1';'chan2'};
+data.fsample  = 1000;
+data.cfg.trl  = zeros(2,3);
+
+%% compute
+
+cfg = [];
+cfg.method    = 'mtmfft';
+cfg.output    = 'powandcsd';
+cfg.tapsmofrq = 4;
+cfg.foilim    = [8 40];
+
+cfg.keeptrials = 'no';
+freq1 = ft_freqanalysis(cfg, data);
+
+cfg.keeptrials = 'yes';
+freq2 = ft_freqanalysis(cfg, data);
+
+cfg = [];
+freq2fd = ft_freqdescriptives(cfg, freq2);
+
+%% compare
+
+if max(abs(freq1.powspctrm(:)-freq2fd.powspctrm(:))./norm(freq1.powspctrm(:)+freq2fd.powspctrm(:)))>1e-10
+  % small errors are expected due to accumulation of numerical errors
+  error('they are different');
+end
+
+