from PyQt5.QtWidgets import QWidget, QVBoxLayout, QHBoxLayout, QPushButton, QFileDialog, QTableWidgetItem, QApplication from PyQt5.QtCore import Qt from qfluentwidgets import TitleLabel, BodyLabel, TableWidget, PushButton, SubtitleLabel, SpinBox, ComboBox, InfoBar,InfoBarPosition, FluentIcon import pyqtgraph as pg # 延迟导入：这些库只在需要时才导入，加快应用启动速度 # import numpy as np # from openpyxl import load_workbook, Workbook class FunctionFitInterface(QWidget): def __init__(self, parent=None): super().__init__(parent) # 延迟导入标志 self._libs_loaded = False self.setObjectName("functionFitInterface") main_layout = QHBoxLayout(self) main_layout.setSpacing(24) # 左侧：数据输入区 left_layout = QVBoxLayout() left_layout.setSpacing(16) self.dataTable = TableWidget(self) self.dataTable.setColumnCount(2) self.dataTable.setHorizontalHeaderLabels(["x", "y"]) self.dataTable.setColumnWidth(0, 125) self.dataTable.setColumnWidth(1, 125) left_layout.addWidget(self.dataTable) btn_layout = QHBoxLayout() add_row_btn = PushButton("添加一行") add_row_btn.clicked.connect(self.add_row) del_row_btn = PushButton("删除选中行") # 新增按钮 del_row_btn.clicked.connect(self.delete_selected_row) # 绑定槽函数 btn_layout.addWidget(add_row_btn) btn_layout.addWidget(del_row_btn) # 添加到布局 left_layout.addLayout(btn_layout) btn_layout = QHBoxLayout() import_btn = PushButton("导入 Excel") import_btn.clicked.connect(self.import_excel) export_btn = PushButton("导出 Excel") export_btn.clicked.connect(self.export_excel) btn_layout.addWidget(import_btn) btn_layout.addWidget(export_btn) left_layout.addLayout(btn_layout) self.dataTable.setMinimumWidth(280) self.dataTable.setMaximumWidth(280) main_layout.addLayout(left_layout, 1) self.add_row() # 右侧：图像展示区 right_layout = QVBoxLayout() right_layout.setSpacing(12) right_layout.addWidget(SubtitleLabel("函数图像预览")) # 占位符，实际的canvas会在_load_heavy_libraries中创建 self.canvas_placeholder = QWidget() self.canvas_layout = QVBoxLayout(self.canvas_placeholder) self.canvas_layout.setContentsMargins(0, 0, 0, 0) right_layout.addWidget(self.canvas_placeholder, stretch=1) self.resultLabel = BodyLabel("") self.resultLabel.setWordWrap(True) # 自动换行 right_layout.addWidget(self.resultLabel) # 拟合阶数和输出语言选择（合并到同一行） options_layout = QHBoxLayout() self.spinBox = SpinBox() self.spinBox.setRange(1, 10) self.spinBox.setValue(2) options_layout.addWidget(SubtitleLabel("拟合阶数")) options_layout.addWidget(self.spinBox) self.langBox = ComboBox() self.langBox.addItems(["C/C++", "Python"]) options_layout.addWidget(SubtitleLabel("输出语言")) options_layout.addWidget(self.langBox) right_layout.addLayout(options_layout) # 代码显示和复制按钮 self.codeLabel = BodyLabel("") self.codeLabel.setWordWrap(True) # 自动换行 right_layout.addWidget(self.codeLabel) btn_layout = QHBoxLayout() # 新增一行布局 fit_btn = PushButton(FluentIcon.UNIT,"拟合并绘图") fit_btn.clicked.connect(self.fit_and_plot) btn_layout.addWidget(fit_btn) copy_btn = PushButton(FluentIcon.COPY, "复制代码") copy_btn.clicked.connect(self.copy_code) btn_layout.addWidget(copy_btn) right_layout.addLayout(btn_layout) main_layout.addLayout(right_layout, 2) def _load_heavy_libraries(self): """延迟加载大型库，提高应用启动速度""" if self._libs_loaded: return global np, load_workbook, Workbook import numpy as np from openpyxl import load_workbook, Workbook # 创建 PyQtGraph 画布 self.plot_widget = pg.PlotWidget() self.plot_widget.setBackground('w') # 白色背景 self.plot_widget.showGrid(x=True, y=True, alpha=0.3) self.plot_widget.setLabel('left', 'y') self.plot_widget.setLabel('bottom', 'x') self.plot_widget.setTitle('graph of a function') # 将 plot_widget 添加到占位符布局中 if hasattr(self, 'canvas_layout'): self.canvas_layout.addWidget(self.plot_widget) self._libs_loaded = True def add_row(self): row = self.dataTable.rowCount() self.dataTable.insertRow(row) # 可选：初始化为空字符串 self.dataTable.setItem(row, 0, QTableWidgetItem("")) self.dataTable.setItem(row, 1, QTableWidgetItem("")) def delete_selected_row(self): selected = self.dataTable.selectedItems() if selected: rows = set(item.row() for item in selected) for row in sorted(rows, reverse=True): self.dataTable.removeRow(row) def import_excel(self): self._load_heavy_libraries() # 延迟加载库 path, _ = QFileDialog.getOpenFileName(self, "导入 Excel", "", "Excel Files (*.xlsx)") if path: wb = load_workbook(path) ws = wb.active self.dataTable.setRowCount(0) for row_data in ws.iter_rows(min_row=2, values_only=True): # 跳过表头 row = self.dataTable.rowCount() self.dataTable.insertRow(row) for col, value in enumerate(row_data[:2]): item = QTableWidgetItem(str(value) if value is not None else "") self.dataTable.setItem(row, col, item) def export_excel(self): self._load_heavy_libraries() # 延迟加载库 path, _ = QFileDialog.getSaveFileName(self, "导出 Excel", "", "Excel Files (*.xlsx)") if path: data = self.parse_data() if data is not None: wb = Workbook() ws = wb.active ws.append(["x", "y"]) for row in data: ws.append(row) wb.save(path) def parse_data(self): data = [] row_count = self.dataTable.rowCount() for row in range(row_count): try: x_item = self.dataTable.item(row, 0) y_item = self.dataTable.item(row, 1) if x_item is None or y_item is None: continue x = float(x_item.text()) y = float(y_item.text()) data.append([x, y]) except Exception: continue return data if data else None def fit_and_plot(self): self._load_heavy_libraries() # 延迟加载库 data = self.parse_data() if not data: self.resultLabel.setText("数据格式错误或为空") self.codeLabel.setText("") return x = np.array([d[0] for d in data]) y = np.array([d[1] for d in data]) degree = self.spinBox.value() coeffs = np.polyfit(x, y, degree) # 用更密集的横坐标画拟合曲线 x_fit = np.linspace(x.min(), x.max(), 100) y_fit = np.polyval(coeffs, x_fit) # 清空并重新绘图 self.plot_widget.clear() # 绘制原始数据点（蓝色散点） scatter = pg.ScatterPlotItem( x=x, y=y, pen=None, brush=pg.mkBrush(0, 0, 255, 120), # 蓝色半透明 size=10, name='raw data' ) self.plot_widget.addItem(scatter) # 绘制拟合曲线（红色线条） pen = pg.mkPen(color=(255, 0, 0), width=2) # 红色线条 curve = self.plot_widget.plot( x_fit, y_fit, pen=pen, name='Fitted curve' ) # 添加图例 self.plot_widget.addLegend() formula = self.poly_formula(coeffs) self.resultLabel.setText(f"拟合公式: {formula}") lang = self.langBox.currentText() code = self.generate_code(coeffs, lang) self.codeLabel.setText(code) def poly_formula(self, coeffs): terms = [] degree = len(coeffs) - 1 for i, c in enumerate(coeffs): power = degree - i if abs(c) < 1e-8: continue if power == 0: terms.append(f"{c:.6g}") elif power == 1: terms.append(f"{c:.6g}*x") else: terms.append(f"{c:.6g}*x^{power}") return " + ".join(terms) def generate_code(self, coeffs, lang): degree = len(coeffs) - 1 if lang == "C/C++": code = "double poly(double x) {\n return " elif lang == "Python": code = "def poly(x):\n return " else: code = "" terms = [] for i, c in enumerate(coeffs): power = degree - i if abs(c) < 1e-8: continue if power == 0: terms.append(f"{c:.6g}") elif power == 1: terms.append(f"{c:.6g}*x") else: terms.append(f"{c:.6g}*pow(x,{power})" if lang == "C/C++" else f"{c:.6g}*x**{power}") code += " + ".join(terms) code += ";\n}" if lang == "C/C++" else "" return code def copy_code(self): clipboard = QApplication.clipboard() clipboard.setText(self.codeLabel.text()) # 弹出提示 InfoBar.success( title='复制成功', content="代码已复制到剪贴板！", orient=Qt.Horizontal, isClosable=True, position=InfoBarPosition.TOP, duration=2000, parent=self )