北邮22级信通院DSP：FIR_DF系统2.0版：用C++程序自主处理第五章习题——对程序运行时间和存储空间的进一步优化

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目录

一、原理 

二、新增变量

三、改进

3.1对hd(n)存储空间和运算速度的改进

3.2对w(n)存储空间和运算速度的改进

3.3对h(n)存储空间和运算速度的改进

四、代码部分

4.1总体代码

4.2代码效果图

4.3运行结果

五、日志

一、原理 

 

可以发现，h(n)和w(n)都是关于n=M中心对称的。

举个例子

以单位冲激响应为例，取M=10，验证每一项的对称性。

#include<iostream>
#include<cmath>
const double PI = acos(-1.0);
using namespace std;
const double MIN = 1e-5;
int main()
{
	system("color 0A");
	int m = 10;
	double temp = 0;
	for (int i = 0; i <= 2*m; i++)
	{
		cout << "第";
		if (i < 10)cout << "0";
		cout<< i << "项:";
		temp = sin((i - m) * 1.0) / ((i - m) * PI);
		if (abs(temp) < MIN)temp = 0;
		cout << temp << endl;
	}
	return 0;
}

输出结果为：

 

发现取值群确实关于M（M=10）呈中心对称。  

举个例子 

以布莱克曼窗为例，取M=10，验证每一项的对称性。

#include<iostream>
#include<cmath>
const double PI = acos(-1.0);
using namespace std;
const double MIN = 1e-5;
int main()
{
	system("color 0A");
	int m = 10;
	double temp = 0;
	for (int i = 0; i <= 2*m; i++)
	{
		cout << "第" << i << "项:";
		temp = 0.42 - 0.50 * cos(i * PI / m) + 0.08 * cos(2 * i * PI / m);
		if (abs(temp) < MIN)temp = 0;
		cout << temp << endl;
	}
	return 0;
}

输出的结果为：

发现取值群确实关于M（M=10）呈中心对称。  

综上， 

对于所有的序列存储，存储空间都可以减少一半；

对于所有的序列运算，计算时间都可以减少一半。

二、新增变量

long double center_hn, center_wn, center_que;

        由于size(hd(n))==size(w(n))==size(h(n))==2*M+1，长度是奇数，所以中心对称点是第M+1项，所以第M+1项的对称项还是自己，这个点比较特殊，需要单独拿出来计算，所以设置了center_hn，center_wn和center_que三个变量，用来储存三个序列的中心对称点，以及进行中心对称点之间的运算。

三、改进

        所有的改进其实都遵循同一原则，即先计算并存储前M项，之后单独计算第M+1项（即中心对称点），最后倒序输出前M项。

3.1对hd(n)存储空间和运算速度的改进

原代码：

void hn_calculate()
{
	cout << endl << "hd(n)的计算结果为:hd(n) = " << endl;
	ld temp = 0;
	bool is_limit = 0;
	for (int i = 0; i < N; i++)
	{
		is_limit = (i == M);
		switch (filter_type)
		{
		case IS_LP:
			temp = (is_limit == 1) ? (c2 / PI) :
				sin((i - M) * c2) / ((i - M) * PI); break;
		case IS_HP:
			temp = (is_limit == 1) ? (1 - c1 / PI) :
				sin((i - M) * PI) / ((i - M) * PI) -
				sin((i - M) * c1) / ((i - M) * PI); break;
		case IS_BP:
			temp = (is_limit == 1) ? (c2 / PI - c1 / PI) :
				sin((i - M) * c2) / ((i - M) * PI) -
				sin((i - M) * c1) / ((i - M) * PI); break;
		case IS_BS:
			temp = (is_limit == 1) ? (c1 / PI + 1 - c2 / PI) :
				sin((i - M) * c1) / ((i - M) * PI) +
				sin((i - M) * PI) / ((i - M) * PI) -
				sin((i - M) * c2) / ((i - M) * PI); break;
		default:
			throw"error:hn_calculate_switch_invalid_filter_type!"; break;
		}
		if (abs(temp) <= MIN)temp = 0;
		que_hn.push_back(temp);
		print(temp, i);
	}
}

改进后的代码：

void hn_calculate()
{
	cout << endl << "hd(n)的计算结果为:hd(n) = " << endl;
	ld temp = 0;
	//入队0——M-1项
	for (int i = 0; i < M; i++)
	{
		switch (filter_type)
		{
		case IS_LP:
			temp = sin((i - M) * c2) / ((i - M) * PI); break;
		case IS_HP:
			temp = sin((i - M) * PI) / ((i - M) * PI) -
				sin((i - M) * c1) / ((i - M) * PI); break;
		case IS_BP:
			temp = sin((i - M) * c2) / ((i - M) * PI) -
				sin((i - M) * c1) / ((i - M) * PI); break;
		case IS_BS:
			temp = sin((i - M) * c1) / ((i - M) * PI) +
				sin((i - M) * PI) / ((i - M) * PI) -
				sin((i - M) * c2) / ((i - M) * PI); break;
		default:
			throw"error:hn_calculate_switch_invalid_filter_type!"; break;
		}

		//近似估计
		if (abs(temp) <= MIN)temp = 0;
		que_hn.push_back(temp);
		print(temp, i);
	}

	//中心值 第M+1个值
	switch (filter_type)
	{
	case IS_LP:
		temp = c2 / PI; break;
	case IS_HP:
		temp = 1 - c1 / PI; break;
	case IS_BP:
		temp = c2 / PI - c1 / PI; break;
	case IS_BS:
		temp = c1 / PI + 1 - c2 / PI; break;
	default:
		throw"error:hn_calculate_center_switch_invalid_filter_type!"; break;
	}
	print(temp, M);
	center_hn = temp;

	//从尾部出队，并从头部入队
	for (int i = M + 1; i < N; i++)
	{
		temp = que_hn.back();
		que_hn.pop_back();
		que_hn.push_front(temp);
		print(temp, i);
	}

	//循环过后，que_hn中的顺序还是0~M项。
	cout << endl << "hd(n)的长度为:" << 2 * que_hn.size() + 1;
	cout << endl << "其中n的范围为[0," << N - 1 << "]" << endl;
	cout << endl << endl;
}

3.2对w(n)存储空间和运算速度的改进

原代码：

void wn_calculate()
{
	cout << endl << "w(n)的计算结果为:w(n) = " << endl;

	ld temp = 0;
	for (int i = 0; i < N; i++)
	{
		temp = window_type.a - window_type.b * cos(i * PI / M) +
			window_type.c * cos(2 * i * PI / M);
		if (abs(temp) <= MIN)temp = 0;
		que_wn.push_back(temp);
		print(temp, i);
	}
	cout << endl << "w(n)的长度为:" << que_wn.size();
	cout << endl << "其中n的范围为[0," << N - 1 << "]" << endl;
}

改进后的代码：

void wn_calculate()
{
	cout << endl << "w(n)的计算结果为:w(n) = " << endl;
	ld temp = 0;
	for (int i = 0; i < M; i++)
	{
		temp = window_type.a - window_type.b * cos(i * PI / M)
			+ window_type.c * cos(2 * i * PI / M);
		que_wn.push_back(temp);
		print(temp, i);
	}

	//中心值
	center_que = 1;
	print(center_que, M);

	for (int i = M + 1; i < N; i++)
	{
		temp = que_wn.back();
		que_wn.pop_back();
		print(temp, i);
		que_wn.push_front(temp);
	}
	cout << endl << "w(n)的长度为:" << 2 * que_wn.size() + 1;
	cout << endl << "其中n的范围为[0," << N - 1 << "]" << endl;
}

3.3对h(n)存储空间和运算速度的改进

原代码：

void que_calculate()
{
	cout << endl << "h(n)的计算结果为:h(n) = " << endl;
	ld temp = 0;
	for (int i = 0; i < N; i++)
	{
		temp = que_hn.front() * que_wn.front();
		que.push_back(temp);
		print(temp, i);
		que_hn.push_back(que_hn.front()); que_hn.pop_front();
		que_wn.push_back(que_wn.front()); que_wn.pop_front();
	}
	cout << endl << "h(n)的长度为:" << que.size();
	cout << endl << "其中n的范围为[0," << N - 1 << "]" << endl;
}

改进后的代码：

void que_calculate()
{
	cout << endl << "h(n)的计算结果为:h(n) = " << endl;
	ld temp = 0;
	if (window_type.type != RECTANG)
	{
		for (int i = 0; i < M; i++)
		{
			temp = que_hn.front() * que_wn.front();
			que.push_back(temp);
			print(temp, i);
			que_hn.push_back(que_hn.front()); que_hn.pop_front();
			que_wn.push_back(que_wn.front()); que_wn.pop_front();
		}

		//中心值
		center_que = center_hn * center_wn;
		print(center_que, M);

		for (int i = M + 1; i < N; i++)
		{
			temp = que.back();
			que.pop_back();
			print(temp, i);
			que.push_front(temp);
		}
	}

	//如果是矩形窗，那就不用计算了，直接输出hn即可。
	else
	{
		for (int i = 0; i < M; i++)
		{
			temp = que_hn.front();
			que_hn.pop_front();
			que_hn.push_back(temp);
			print(temp, i);
		}

		//中心值
		print(center_hn, M);

		for (int i = M + 1; i < N; i++)
		{
			temp = que_hn.back();
			que_hn.pop_back();
			que_hn.push_front(temp);
			print(temp, i);
		}
	}
	cout << endl << "h(n)的长度为:" << 2 * que.size() + 1;
	cout << endl << "其中n的范围为[0," << N - 1 << "]" << endl;
}

四、代码部分

4.1总体代码

#include<iostream>
#include<cmath>
#include<deque>
#include <sstream>
#include<iomanip>
#include<cstring>
#include<string>
#include<deque>
using namespace std;

#define ERROR    0
#define RECTANG  1
#define	HANNING  2
#define HAMMING  3
#define BLACKMN  4

#define IS_LP 5
#define IS_HP 6
#define IS_BP 7
#define IS_BS 8
#define UN_KNOWN 9

#define MIN 10e-9
typedef long double ld;
const double PI = acos(-1.0);
//表达式中对小数的精确度
const int define_setpercision = 2;
//阻带衰减最大近似容忍度
const int tolerate = 3;

struct window_data
{
	int type;
	double a, b, c;
	ld accurate_transition_bandwith;
	ld approximate_transition_bandwith;
	ld sidelobe_peak_attenuation;
	ld min_stopband_attenuation;

	bool operator == (window_data w)
	{
		return ((this->type == w.type) && (this->a == w.a) && (this->b == w.b) && (this->c == w.c) &&
			(this->accurate_transition_bandwith == w.accurate_transition_bandwith) &&
			(this->approximate_transition_bandwith == w.approximate_transition_bandwith) &&
			(this->sidelobe_peak_attenuation == w.sidelobe_peak_attenuation) &&
			(this->min_stopband_attenuation == w.min_stopband_attenuation)) ? true : false;
	}
	friend ostream& operator <<(ostream& output, window_data window_type)
	{
		output << "window_type_data_detecting……" << endl;
		output << "window_type.type = " << window_type.type << endl;
		output << "window_type.a = " << window_type.a << endl;
		output << "window_type.b = " << window_type.b << endl;
		output << "window_type.c = " << window_type.c << endl;
		output << "window_type.accurate_transition_bandwith =    " <<
			window_type.accurate_transition_bandwith << endl;
		output << "window_type.approximate_transition_bandwith = " <<
			window_type.approximate_transition_bandwith << endl;
		output << "window_type.sidelobe_peak_attenuation =       " <<
			window_type.sidelobe_peak_attenuation << endl;
		output << "window_type.min_stopband_attenuation =        " <<
			window_type.min_stopband_attenuation << endl;
		output << endl << endl;
		return output;
	}
};

window_data windows[5] =
{
	{},
	{ RECTANG, 1.00, 0.00, 0.00, 1.80 * PI, 4.00 * PI, 13, 21 },
	{ HANNING, 0.50, 0.50, 0.00, 6.20 * PI, 8.00 * PI, 32, 44 },
	{ HAMMING, 0.54, 0.46, 0.00, 6.60 * PI, 8.00 * PI, 43, 53 },
	{ BLACKMN, 0.42, 0.50, 0.08, 11.0 * PI, 12.0 * PI, 58, 74 }
};

int filter_type;
window_data window_type;
static int N, M;

ld p1, p2, s1, s2, As, fs, c1, c2;

deque<ld>que_hn;	//长度N
deque<ld>que_wn;	//长度N
deque<ld>que;		//长度N

ld center_hn, center_wn, center_que;

//选择窗的类型
window_data choose()
{
	int i = 1;
	while (As > windows[i].min_stopband_attenuation)i++;
	if (i < 5)return windows[i];
	else if (i >= 5 && (As - windows[4].min_stopband_attenuation) <= tolerate)return windows[4];
	else
		throw"error:non_window_suits!";
}

void print(ld data, int pos)
{
	cout << setiosflags(ios::fixed) <<
		setprecision(4) << showbase << data << " ";
	if (pos % 5 == 4)cout << endl;
}

//判断选通滤波器类型
int check_types(ld p1, ld p2, ld s1, ld s2)
{
	if (p1 > p2 || s1 > s2 || s1 == p2 ||
		s2 == p1 || s1 == s2 || p1 == p2)
		return ERROR;
	if (s1 * p1 != 0)
		return (p2 > p1 && s2 > s1 && p1 != s1 && p2 != s2) ?
		((p1 > s1) ? IS_BP : IS_BS) : (ERROR);
	else
		return (s2 != p2) ? (s2 < p2 ? IS_HP : IS_LP) : (ERROR);
}

void change()
{
	//数字频率转换为数字角频率wp1,wp2,ws1,ws2;
	p1 *= (2 * PI / fs); p2 *= (2 * PI / fs);
	s1 *= (2 * PI / fs); s2 *= (2 * PI / fs);
	//求得wc1,wc2，相当于w0 - wc, w0 + wc;
	c1 = (p1 + s1) / 2; c2 = (p2 + s2) / 2;
	//计算N、M
	window_type = choose();
	if (filter_type == IS_BP || filter_type == IS_BS)
		if (abs(s2 - p2) != abs(s1 - p1))throw"error:非对称过渡带宽!";
	//谁不等于0就用谁
	N = (s1 - p1 == 0) ?
		ceil(window_type.accurate_transition_bandwith / abs(s2 - p2)) :
		ceil(window_type.accurate_transition_bandwith / abs(s1 - p1));
	N = (N % 2 == 1) ? N : (N + 1);
	M = (N - 1) / 2;
}



auto format_double_value(double val, int fixed) {
	std::ostringstream oss;
	oss << std::setprecision(fixed) << val;
	return oss.str();
}

void hn_output()
{
	cout << endl << "hd(n)表达式为:h(n) = ";
	string string_pi = "sin(n-" + format_double_value(M, define_setpercision) + ")π/"
		+ "((n-" + to_string(M) + ")π)";
	string string_c1 = "sin(n-" + to_string(M) + ")"
		+ format_double_value(c1 / PI, define_setpercision) + "π/"
		+ "((n-" + to_string(M) + ")π)";
	string string_c2 = "sin(n-" + to_string(M) + ")"
		+ format_double_value(c2 / PI, define_setpercision) + "π/"
		+ "((n-" + to_string(M) + ")π)";
	//对lp来说，c1=0，对hp来说，c2=0
	switch (filter_type)
	{
	case IS_LP:
		cout << string_c2; break;
	case IS_HP:
		cout << string_pi << " - " << string_c1; break;
	case IS_BP:
		cout << string_c2 << " - " << string_c1; break;
	case IS_BS:
		cout << string_c1 << " + " << string_pi
			<< " - " << string_c2; break;
	default:
		throw"error:hn_output!"; break;
	}
	cout << endl << "其中n的范围为[0," << N - 1 << "]" << endl;
}

//原代码
/*
void hn_calculate()
{
	cout << endl << "hd(n)的计算结果为:hd(n) = " << endl;
	ld temp = 0;
	bool is_limit = 0;
	for (int i = 0; i < N; i++)
	{
		is_limit = (i == M);
		switch (filter_type)
		{
		case IS_LP:
			temp = (is_limit == 1) ? (c2 / PI) :
				sin((i - M) * c2) / ((i - M) * PI); break;
		case IS_HP:
			temp = (is_limit == 1) ? (1 - c1 / PI) :
				sin((i - M) * PI) / ((i - M) * PI) -
				sin((i - M) * c1) / ((i - M) * PI); break;
		case IS_BP:
			temp = (is_limit == 1) ? (c2 / PI - c1 / PI) :
				sin((i - M) * c2) / ((i - M) * PI) -
				sin((i - M) * c1) / ((i - M) * PI); break;
		case IS_BS:
			temp = (is_limit == 1) ? (c1 / PI + 1 - c2 / PI) :
				sin((i - M) * c1) / ((i - M) * PI) +
				sin((i - M) * PI) / ((i - M) * PI) -
				sin((i - M) * c2) / ((i - M) * PI); break;
		default:
			throw"error:hn_calculate_switch_invalid_filter_type!"; break;
		}
		if (abs(temp) <= MIN)temp = 0;
		que_hn.push_back(temp);
		print(temp, i);
	}
}
*/

//改进后的代码
void hn_calculate()
{
	cout << endl << "hd(n)的计算结果为:hd(n) = " << endl;
	ld temp = 0;
	//入队0——M-1项
	for (int i = 0; i < M; i++)
	{
		switch (filter_type)
		{
		case IS_LP:
			temp = sin((i - M) * c2) / ((i - M) * PI); break;
		case IS_HP:
			temp = sin((i - M) * PI) / ((i - M) * PI) -
				sin((i - M) * c1) / ((i - M) * PI); break;
		case IS_BP:
			temp = sin((i - M) * c2) / ((i - M) * PI) -
				sin((i - M) * c1) / ((i - M) * PI); break;
		case IS_BS:
			temp = sin((i - M) * c1) / ((i - M) * PI) +
				sin((i - M) * PI) / ((i - M) * PI) -
				sin((i - M) * c2) / ((i - M) * PI); break;
		default:
			throw"error:hn_calculate_switch_invalid_filter_type!"; break;
		}

		//近似估计
		if (abs(temp) <= MIN)temp = 0;
		que_hn.push_back(temp);
		print(temp, i);
	}

	//中心值 第M+1个值
	switch (filter_type)
	{
	case IS_LP:
		temp = c2 / PI; break;
	case IS_HP:
		temp = 1 - c1 / PI; break;
	case IS_BP:
		temp = c2 / PI - c1 / PI; break;
	case IS_BS:
		temp = c1 / PI + 1 - c2 / PI; break;
	default:
		throw"error:hn_calculate_center_switch_invalid_filter_type!"; break;
	}
	print(temp, M);
	center_hn = temp;

	//从尾部出队，并从头部入队
	for (int i = M + 1; i < N; i++)
	{
		temp = que_hn.back();
		que_hn.pop_back();
		que_hn.push_front(temp);
		print(temp, i);
	}

	//循环过后，que_hn中的顺序还是0~M项。
	cout << endl << "hd(n)的长度为:" << 2 * que_hn.size() + 1;
	cout << endl << "其中n的范围为[0," << N - 1 << "]" << endl;
	cout << endl << endl;
}


//内部调用
string string_create(double A, double B, double C)
{
	string string_a, string_b, string_c, string_final;
	string_a = format_double_value(A, define_setpercision);
	string_b = " - " + format_double_value(B, define_setpercision)
		+ "cos(2nπ/("
		+ to_string(N) + "-1))";
	string_c = " + " + format_double_value(C, define_setpercision)
		+ "cos(4nπ/("
		+ to_string(N) + "-1))";
	if (B)string_a += string_b;
	if (C)string_a += string_c;
	return string_a;
}

void wn_output()
{
	cout << endl << "w(n)的表达式为:w(n) = ";
	if (window_type.type >= RECTANG && window_type.type <= BLACKMN)
		cout << string_create(window_type.a, window_type.b, window_type.c);
	else throw"error:wn_output_invalid_window_type.type!";
	cout << endl << "其中n的范围为[0," << N - 1 << "]" << endl;
}

//原代码
/*
void wn_calculate()
{
	cout << endl << "w(n)的计算结果为:w(n) = " << endl;

	ld temp = 0;
	for (int i = 0; i < N; i++)
	{
		temp = window_type.a - window_type.b * cos(i * PI / M) +
			window_type.c * cos(2 * i * PI / M);
		if (abs(temp) <= MIN)temp = 0;
		que_wn.push_back(temp);
		print(temp, i);
	}
	cout << endl << "w(n)的长度为:" << que_wn.size();
	cout << endl << "其中n的范围为[0," << N - 1 << "]" << endl;
}*/

//改进后的代码
void wn_calculate()
{
	cout << endl << "w(n)的计算结果为:w(n) = " << endl;
	ld temp = 0;
	for (int i = 0; i < M; i++)
	{
		temp = window_type.a - window_type.b * cos(i * PI / M)
			+ window_type.c * cos(2 * i * PI / M);
		que_wn.push_back(temp);
		print(temp, i);
	}

	//中心值
	center_que = 1;
	print(center_que, M);

	for (int i = M + 1; i < N; i++)
	{
		temp = que_wn.back();
		que_wn.pop_back();
		print(temp, i);
		que_wn.push_front(temp);
	}
	cout << endl << "w(n)的长度为:" << 2 * que_wn.size() + 1;
	cout << endl << "其中n的范围为[0," << N - 1 << "]" << endl;
}


//原代码
/*
void que_calculate()
{
	cout << endl << "h(n)的计算结果为:h(n) = " << endl;
	ld temp = 0;
	for (int i = 0; i < N; i++)
	{
		temp = que_hn.front() * que_wn.front();
		que.push_back(temp);
		print(temp, i);
		que_hn.push_back(que_hn.front()); que_hn.pop_front();
		que_wn.push_back(que_wn.front()); que_wn.pop_front();
	}
	cout << endl << "h(n)的长度为:" << que.size();
	cout << endl << "其中n的范围为[0," << N - 1 << "]" << endl;
}
*/

//改进后的代码
void que_calculate()
{
	cout << endl << "h(n)的计算结果为:h(n) = " << endl;
	ld temp = 0;
	if (window_type.type != RECTANG)
	{
		for (int i = 0; i < M; i++)
		{
			temp = que_hn.front() * que_wn.front();
			que.push_back(temp);
			print(temp, i);
			que_hn.push_back(que_hn.front()); que_hn.pop_front();
			que_wn.push_back(que_wn.front()); que_wn.pop_front();
		}

		//中心值
		center_que = center_hn * center_wn;
		print(center_que, M);

		for (int i = M + 1; i < N; i++)
		{
			temp = que.back();
			que.pop_back();
			print(temp, i);
			que.push_front(temp);
		}
	}

	//如果是矩形窗，那就不用计算了，直接输出hn即可。
	else
	{
		for (int i = 0; i < M; i++)
		{
			temp = que_hn.front();
			que_hn.pop_front();
			que_hn.push_back(temp);
			print(temp, i);
		}

		//中心值
		print(center_hn, M);

		for (int i = M + 1; i < N; i++)
		{
			temp = que_hn.back();
			que_hn.pop_back();
			que_hn.push_front(temp);
			print(temp, i);
		}
	}
	cout << endl << "h(n)的长度为:" << 2 * que.size() + 1;
	cout << endl << "其中n的范围为[0," << N - 1 << "]" << endl;
}



void input()
{
	string get_input;
	cout << endl << "欢迎登录FIR_DF设计系统!" << endl;
	cout << endl << "我们需要获取您的一些数据要求~" << endl;
	cout << "请输入您想设计的数字滤波器类型(包括lp、hp、bp、bs、unknown):";
	cin >> get_input;
	if (get_input == "lp")filter_type = IS_LP;
	else if (get_input == "hp")filter_type = IS_HP;
	else if (get_input == "bp")filter_type = IS_BP;
	else if (get_input == "bs")filter_type = IS_BS;
	else if (get_input == "unknown") filter_type == UN_KNOWN;
	else { cout << "error:输入错误！"; exit(0); }

	cout << endl << "下面是关于键入频率和衰减系数的指标的一些声明。\n\
声明:\n\
因为在模拟域中，低通滤波器的通带和阻带下截止频率均趋于负无穷，\n\
所以在数字域中，低通滤波器的通带和阻带下截止频率均趋于0，\n\
所以如果是低通滤波器，程序默认在通带和阻带下截频位置(p1、s1)键入0；\n\
同理，\n\
因为在模拟域中，高通滤波器的通带和阻带上截止频率均趋于正无穷，\n\
所以在数字域中，高通滤波器的通带和阻带上截止频率均趋于0，\n\
所以如果是低通滤波器，程序默认在通带和阻带上截频位置(p2、s2)键入0；" << endl;

	cout << endl << "请输入取样频率(Hz):"; cin >> fs;

	cout << endl << "请输入通带起始频率p1(Hz):";
	if (filter_type == IS_LP) { p1 = 0; cout << p1; }
	else cin >> p1;
	cout << endl << "请输入通带截止频率p2(Hz):";
	if (filter_type == IS_HP) { p2 = 0; cout << p2; }
	else cin >> p2;

	cout << endl << "请输入阻带起始频率s1(Hz):";
	if (filter_type == IS_LP) { s1 = 0; cout << s1; }
	else cin >> s1;
	cout << endl << "请输入阻带截止频率s2(Hz):";
	if (filter_type == IS_HP) { s2 = 0; cout << s2; }
	else cin >> s2;

	cout << endl << "请输入阻带衰减常数(dB):"; cin >> As;

	cout << endl;
	cout << "运算结果为:" << endl;
}

void data_output()
{
	cout << "data_output_for_detect…" << endl;
	cout << "c1 = " << c1 << endl;
	cout << "c2 = " << c2 << endl;
	cout << "N = " << N << endl;
	cout << "M = " << M << endl;
	cout << "所选窗函数类型为:";
	switch (window_type.type)
	{
	case RECTANG:cout << "RECTANG" << endl; break;
	case HANNING:cout << "HANNING" << endl; break;
	case HAMMING:cout << "HAMMING" << endl; break;
	case BLACKMN:cout << "BLACKMN" << endl; break;
	default:throw"error:data_output!"; break;
	}
	hn_output();
	hn_calculate();
	wn_output();
	wn_calculate();
	que_calculate();
}

void complication()
{
	system("color 0A");
	//input();
	filter_type = IS_LP, fs = 10000, p1 = 0, p2 = 2000, s1 = 0, s2 = 3000, As = 40;
	//filter_type = IS_BP, fs = 22000, p1 = 3500, s1 = 3000, p2 = 4500, s2 = 5000, As = 50;
	change();
	data_output();
}

int main()
{
	try
	{
		complication();
	}
	catch (const char* cc)
	{
		cout << cc << endl;
		exit(0);
	}
	return 0;
}

4.2代码效果图

4.3运行结果

五、日志

暂无。

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