[pyqtgraph] SignalProxyを理解してグラフ上にカーソルを追従する十字線を作成する - Qiita

で色々なサンプルグラフが見れます。今回参考にしたのはCrosshair / Mouse interactionです。 SignalProxy SignalProxyのdocの内容 Object which collects rapid-fire signals and condenses them into a single signal or a rate-limited stream of signals. Used, for example, to prevent a SpinBox from generating multiple signals when the mouse wheel is rolled over it. Emits sigDelayed after input signals have stopped for a certain period of time.