code: def imageHoverEvent(event):
      """Show the position, pixel, and value under the mouse cursor."""
      if event.isExit():
          p1.setTitle("")
          return
      pos = event.pos()
      i, j = pos.y(), pos.x()
      i = int(np.clip(i, 0, data.shape[0] - 1))
      j = int(np.clip(j, 0, data.shape[1] - 1))
      val = data[i, j]
      ppos = img.mapToParent(pos)
      x, y = ppos.x(), ppos.y()
      p1.setTitle(
          "pos: (%0.1f, %0.1f)  pixel: (%d, %d)  value: %.3g"
          % (x, y, i, j, val)
      )
  
imports: import numpy
  import pyqtgraph
  from pyqtgraph.Qt import QtGui
label_desc: Use image node_id 3 for calling a global function with example usage: imageHoverEvent(event) without return types