Compute the min length for FFT according to AFNI's algorithm, By Xiao-Wei Song
------------------------------------------------------------------------------------------------------------------------------
Copyright(c) 2007~2010
State Key Laboratory of Cognitive Neuroscience and Learning in Beijing Normal University
Written by Xiao-Wei Song
http://resting-fmri.sourceforge.net
<a href="Dawnwei.Song@gmail.com">Mail to Author</a>: Xiaowei Song
Version=1.0;
Release=20070903;0001 function Result = rest_nextpow2_one35(n) 0002 %Compute the min length for FFT according to AFNI's algorithm, By Xiao-Wei Song 0003 %------------------------------------------------------------------------------------------------------------------------------ 0004 % Copyright(c) 2007~2010 0005 % State Key Laboratory of Cognitive Neuroscience and Learning in Beijing Normal University 0006 % Written by Xiao-Wei Song 0007 % http://resting-fmri.sourceforge.net 0008 % <a href="Dawnwei.Song@gmail.com">Mail to Author</a>: Xiaowei Song 0009 % Version=1.0; 0010 % Release=20070903; 0011 0012 if length(n)>1 0013 n = cast(length(n),class(n)); 0014 end 0015 if n<16 0016 Result =2^nextpow2(n); 0017 return; 0018 end 0019 0020 limit =nextpow2(n); %n=134, limit=8 0021 tbl=[2^(limit-1):2^limit]; %tbl =128, 129, ... , 256 0022 tbl =tbl(find(tbl>=n)); %tbl =134, 135, ... , 256 0023 for x=1:length(tbl) 0024 Result =tbl(x); 0025 [f,p]=log2(Result); 0026 if ~isempty(f) & f == 0.5 %Copy from nextpow2.m 0027 return; 0028 end 0029 if mod(Result,3*5)==0 0030 y= Result /(3*5); 0031 [f,p]=log2(y); 0032 if ~isempty(f) & f == 0.5 %Copy from nextpow2.m 0033 return; 0034 end 0035 end 0036 if mod(Result,3)==0 0037 y= Result /3; 0038 [f,p]=log2(y); 0039 if ~isempty(f) & f == 0.5 %Copy from nextpow2.m 0040 return; 0041 end 0042 end 0043 if mod(Result,5)==0 0044 y= Result /5; 0045 [f,p]=log2(y); 0046 if ~isempty(f) & f == 0.5 %Copy from nextpow2.m 0047 return; 0048 end 0049 end 0050 end 0051 Result =NaN; % Should not reach, except when n=1 0052 0053 % csfft_nextup35 in AFNI list 1~1024, 20070516, dawnsong 0054 % 2 0055 % 4 0056 % 6 0057 % 8 0058 % 10 0059 % 12 0060 % 16 0061 % 20 0062 % 24 0063 % 30 0064 % 32 0065 % 40 0066 % 48 0067 % 60 0068 % 64 0069 % 80 0070 % 96 0071 % 120 0072 % 128 0073 % 160 0074 % 192 0075 % 240 0076 % 256 0077 % 320 0078 % 384 0079 % 480 0080 % 512 0081 % 640 0082 % 768 0083 % 960 0084 % 1024