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<p style="margin-top:0;margin-bottom:0">Dear EEGLABers (particularly Jason Palmer)</p>
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<p style="margin-top:0;margin-bottom:0">Ive been using EEGLAB and AMICA for many years now and theres been an issue I've been meaning to ask about for a while now. Sometimes when I run an AMICA, the 'LL' and 'nd' in the final iteration are NaNs. For example
(last couple lines of output):</p>
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<p style="margin-top:0;margin-bottom:0">...</p>
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<div> iter 3993 lrate = 0.0000004768 LL = 0.2151813642 nd = 0.0066193118, D = 0.11548E+01 0.11548E+01 ( 44.53 s, 198.0 h)</div>
<div> iter 3994 lrate = 0.0000004768 LL = 0.2151813668 nd = 0.0066193124, D = 0.11548E+01 0.11548E+01 ( 44.42 s, 197.5 h)</div>
<div> iter 3995 lrate = 0.0000004768 LL = 0.2151813695 nd = 0.0066193130, D = 0.11548E+01 0.11548E+01 ( 44.42 s, 197.5 h)</div>
<div> iter 3996 lrate = 0.0000004768 LL = 0.2151813720 nd = 0.0066193133, D = 0.11548E+01 0.11548E+01 ( 44.56 s, 198.1 h)</div>
<div> iter 3997 lrate = 0.0000004768 LL = 0.2151813746 nd = 0.0066193139, D = 0.11548E+01 0.11548E+01 ( 44.27 s, 196.8 h)</div>
<div> iter 3998 lrate = 0.0000004768 LL = 0.2151813771 nd = 0.0066193143, D = 0.11548E+01 0.11548E+01 ( 44.55 s, 198.0 h)</div>
<div> iter 3999 lrate = 0.0000004768 LL = 0.2151813797 nd = 0.0066193143, D = 0.11548E+01 0.11548E+01 ( 44.49 s, 197.7 h)</div>
<div> iter 4000 lrate = 0.0000004768 LL = 0.2151813823 nd = 0.0066193152, D = 0.11548E+01 0.11548E+01 ( 44.05 s, 195.8 h)</div>
<div> iter 4001 lrate = 0.0000004768 LL = 0.2151813824 nd = 0.0066193255, D = 0.11548E+01 0.11548E+01 ( 48.06 s, 213.6 h)</div>
<div> iter 4002 lrate = 0.0000004768 LL = 0.2151813847 nd = 0.0066193309, D = 0.11548E+01 0.11548E+01 ( 44.39 s, 197.3 h)</div>
<div> iter 4003 lrate = 0.0000004768 LL = 0.2151813871 nd = 0.0066193324, D = 0.11548E+01 0.11548E+01 ( 44.35 s, 197.1 h)</div>
<div> iter 4004 lrate = 0.0000004768 LL = 0.2151813892 nd = 0.0066193335, D = 0.11548E+01 0.11548E+01 ( 44.49 s, 197.7 h)</div>
<div> iter 4005 lrate = 0.0000004768 LL = 0.2151813914 nd = 0.0066193340, D = 0.11548E+01 0.11548E+01 ( 44.62 s, 198.2 h)</div>
<div> iter 4006 lrate = 0.0000004768 LL = NaN nd = NaN, D = 0.11548E+01 0.11548E+01 ( 44.28 s, 196.7 h)</div>
<div> Got NaN! Exiting ...</div>
<div>... done. Execution time: -10.23 h </div>
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<p style="margin-top:0;margin-bottom:0">Since first noticing this till now, I have code that checks the output for this issue and reruns the AMICA. A lot of the time it will eventually and properly end with the learning rate not decreasing by 1e-9 for five
iterations (I think thats what it is). Ive checked the data, it seems fine.</p>
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<p style="margin-top:0;margin-bottom:0">I guess what I am asking is: "Is this an issue?" or am I incorrectly classifying it as an issue. If it is an issue, Im wondering why it doesnt reset itself.</p>
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<p style="margin-top:0;margin-bottom:0">Kind regards,</p>
<p style="margin-top:0;margin-bottom:0">Tyler</p>
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<div><font face="Arial"><i>Tyler Grummett ( BBSc, BSc(Hons I))</i></font></div>
<div><font face="Arial"><i>PhD Candidate</i></font></div>
<div><font face="Arial"><i>Brain Signals Laboratory</i></font></div>
<div><font face="Arial"><i>Multimodal Recording Facility</i></font></div>
<div><font face="Arial"><i>Flinders University Tonsley Building</i></font></div>
<div><font face="Arial"><i>Rm 4.17</i></font></div>
<div><font face="Arial"><i>Ext 19573</i></font></div>
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