%?dft?low?pass?filter

function?output=dftfilter（inputfreq_fundfs）
%?input:input?series
%?freq_fund:fundamental?frequency
%?fs:sampling?frequency
%?output:?the?signal?after?filtering?
N=length（input）;
y=fft（inputN）;?????????????????????????????????%?fft

fund_location=freq_fund*N/fs;???????????????????%信號采樣的周期數
y（1）=0;
y（2*fund_location+1:end-2*fund_location-1）=0;???%將非基波信號，處于兩個基波之間的值設為零濾除

output=ifft（yN）;???????????????????????????????%ifft


%?for?num=1:N
%?????if?real（y（num））>0
%?????????y（num）=abs（y（num））;
%?????else
%?????????y（num）=-1*abs（y（num））;
%?????end
%?end

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2011-05-08?09:18??harmonics_gui\
?????文件?????????635??2011-05-08?09:18??harmonics_gui\dftfilter.m
?????文件????????4704??2011-05-08?09:18??harmonics_gui\frequency_test.m
?????文件???????30073??2011-05-08?09:18??harmonics_gui\harmonics_gui.asv
?????文件???????15558??2011-05-08?09:18??harmonics_gui\harmonics_gui.fig
?????文件???????30121??2011-05-08?09:18??harmonics_gui\harmonics_gui.m
?????文件?????????502??2011-05-08?09:18??harmonics_gui\試驗總結.txt