C++Qt不用UI形式绘制出频率响应曲线和幅度响应曲线

为了在C++Qt中绘制频率响应曲线和幅度响应曲线，可以使用Qt Charts模块中的QChart和QLineSeries类，以及Qt Math Module中的QVector和qExp函数。以下是一个示例代码，用于生成一个简单的频率响应和幅度响应曲线：

#include <QtCharts/QChart>
#include <QtCharts/QChartView>
#include <QtCharts/QLineSeries>
#include <QtWidgets/QApplication>
#include <QtWidgets/QMainWindow>
#include <QtMath>

QT_CHARTS_USE_NAMESPACE

int main(int argc, char *argv[]) {
    QApplication a(argc, argv);

    // 创建线系列
    QLineSeries *frequencyResponseSeries = new QLineSeries();
    QLineSeries *amplitudeResponseSeries = new QLineSeries();

    // 设置采样频率和截止频率
    const int samplingFrequency = 8000;   // 采样频率
    const int cutoffFrequency = 1000;     // 截止频率

    // 计算频率响应和幅度响应
    const int n = 1000;
    QVector<double> frequencyResponse(n);
    QVector<double> amplitudeResponse(n);
    for (int i = 0; i < n; i++) {
        double frequency = (double)i * samplingFrequency / n;
        double w = 2.0 * M_PI * frequency;
        double x = w / cutoffFrequency;
        double magnitude = 1.0 / qSqrt(1.0 + x * x);
        double phase = -qAtan(x);
        frequencyResponse[i] = phase;
        amplitudeResponse[i] = magnitude;
        frequencyResponseSeries->append(frequency, phase);
        amplitudeResponseSeries->append(frequency, magnitude);
    }

    // 创建图表并添加线系列
    QChart *frequencyResponseChart = new QChart();
    frequencyResponseChart->legend()->hide();
    frequencyResponseChart->addSeries(frequencyResponseSeries);
    frequencyResponseChart->setTitle("Frequency Response");

    QChart *amplitudeResponseChart = new QChart();
    amplitudeResponseChart->legend()->hide();
    amplitudeResponseChart->addSeries(amplitudeResponseSeries);
    amplitudeResponseChart->setTitle("Amplitude Response");

    // 创建图表视图并设置大小
    QChartView *frequencyResponseChartView = new QChartView(frequencyResponseChart);
    frequencyResponseChartView->setRenderHint(QPainter::Antialiasing);
    frequencyResponseChartView->resize(800, 600);

    QChartView *amplitudeResponseChartView = new QChartView(amplitudeResponseChart);
    amplitudeResponseChartView->setRenderHint(QPainter::Antialiasing);
    amplitudeResponseChartView->resize(800, 600);

    // 创建主窗口并设置图表视图为中心窗口
    QMainWindow window;
    window.setCentralWidget(frequencyResponseChartView);
    window.resize(800, 600);
    window.show();

    // 显示幅度响应曲线
    amplitudeResponseChartView->show();

    return a.exec();
}

这个示例代码生成了一个简单的频率响应和幅度响应曲线，并将它们分别显示在两个Qt主窗口中。你可以根据需要修改数据和图表的设置来满足具体的需求。