3D grid size control

[Radhika Prasad]

I am unable to control the size of the 3D grid which comes in a default 20x20x20 size.

I am attaching the code snippet:

class Visualizer(object):

    def __init__(self):

        self.traces = dict()

        self.app = QtGui.QApplication(sys.argv)

        self.w = gl.GLViewWidget()

        self.w.opts['distance'] = 40

        self.w.setWindowTitle('pyqtgraph example: GLLinePlotItem')

        self.w.setGeometry(0, 110, 1920, 1080)

        self.w.show()

        # create the background grids

        gx = gl.GLGridItem()

        gx.rotate(90, 0, 1, 0)

        gx.translate(-3, 0, 0)

        #gx.setSize(50)

        self.w.addItem(gx)

        gy = gl.GLGridItem()

        gy.rotate(90, 1, 0, 0)

        gy.translate(0, -3, 0)

        self.w.addItem(gy)

        gz = gl.GLGridItem()

        gz.translate(0, 0, -3)

        self.w.addItem(gz)

        self.n = 100

        self.y = np.linspace(-3, 25, self.n)

        self.x = np.linspace(-3, 25, self.m)

Please help me in making a bigger grid (say 50x50x50).