関数imsequence2_absmaxindex_limitfreq マニュアル

(The documentation of function imsequence2_absmaxindex_limitfreq)
Last Update: 2025/8/1


◆機能・用途(Purpose)

指定した周波数範囲におけるフーリエスペクトルの絶対値最大値を探し、 対応するサンプル番号を返す。
Search the absolute maximum value of a Fourier spectrum in a specified frequency window, and return the index of the corresponding sample.

◆形式(Format)

#include <sequence/statistics.h>
inline int imsequence2_absmaxindex_limittime
(struct imsequence2 seq,const double fmin,const double fmax)


◆引数(Arguments)

seq 絶対値最大値を探索したいフーリエスペクトルを表す構造体。
A structure to represent the Fourier spectrum for which the absolute maximum value is to be searched.
fmin 絶対値最大値を探す周波数範囲の下限(\(f_{min}\))。
The lower limit, \(f_{min}\), of the frequency window to search the absolute maximum value.
fmax 絶対値最大値を探す周波数範囲の上限(\(f_{max}\))。
The upper limit, \(f_{max}\), of the frequency window to search the absolute maximum value.


◆戻り値(Return value)

\([f_{min},f_{max}]\)の周波数範囲における seq.valueの配列要素の絶対値最大値に対応する配列要素番号。 \(f_{min}\), \(f_{max}\)がサンプル周波数でない場合は内側に丸められる。
The index of the array component corresponding to the absolute maximum value of seq.value in a frequency window \([f_{min},f_{max}]\). If \(f_{min}\) and \(f_{max}\) are not at sample frequencies, the frequency window is rounded inward.

◆使用例(Example)

struct imsequence2 seq=get_imsequence2_memory(8,0.0,0.1);
seq.value[0]=1.0+2.0∗I;
seq.value[1]=3.0-4.0∗I;
seq.value[2]=-5.0+6.0∗I;
seq.value[3]=2.0+3.0∗I;
seq.value[4]=0.0;
seq.value[5]=-4.0+8.0∗I;
seq.value[6]=2.5-3.5∗I;
seq.value[7]=-1.5+2.5∗I;
int absmax_index=sequence_absmaxindex_limittime(seq,0.1,0.4);

この例ではabsmax_index=2となる。
In this example, the value of absmax_index is 2.