# plot a 2d numpy.ndarray with vtkStructuredGrid

**URL:** https://discourse.vtk.org/t/plot-a-2d-numpy-ndarray-with-vtkstructuredgrid/13432
**Category:** Support
**Tags:** python
**Created:** [March 4, 2024, 11:15am UTC](https://discourse.vtk.org/t/plot-a-2d-numpy-ndarray-with-vtkstructuredgrid/13432 "2024-03-04T11:15:36Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![sian](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/s/ecd19e/32.png) [@sian](https://discourse.vtk.org/u/sian)
#### Post date: [March 4, 2024, 11:15am UTC](https://discourse.vtk.org/t/plot-a-2d-numpy-ndarray-with-vtkstructuredgrid/13432/1 "2024-03-04T11:15:36Z")

</div>

Hi everyone:

I’m a beginner of VTK and want to use vtkStructuredGrid to plot a 2d numpy.ndarray data. The size is 768 x 1201, but there are some problems in my code:

 ![image](https://discourse.vtk.org/uploads/default/original/2X/6/6cd0da8791bd1337bfeae90b0852a1447d8d591c.jpeg)

where the real image should be like:

 ![image](https://discourse.vtk.org/uploads/default/original/2X/2/29aff7cba5417ddfe82bad9d458c4f6f2617b4e2.jpeg)

my code is:

```auto
    def sliceToStructuredGrid3(self, pos: []):
        self._tmp_point_data_array = numpy_support.numpy_to_vtk(num_array=self._data[pos, :, :].ravel(), deep=False,
                                                                array_type=vtk.VTK_FLOAT)
        self._point_data_array = vtk.vtkFloatArray()
        self._point_data_array.SetNumberOfComponents(1)
        self._point_data_array.SetName("Scalars")
        self._point_data_array.SetArray(self._tmp_point_data_array, 1 * self._num_n2 * self._num_n1, 1)

        self._tmp_point_array = (
                (np.column_stack(np.where(np.ones_like(self._data[pos, :, :]))) + 0) * 1 * 1).astype(
            np.float32)
        self._point_array = vtk.vtkFloatArray()
        self._point_array.SetNumberOfComponents(3)
        self._point_array.SetNumberOfTuples(self._tmp_point_array.shape[0])
        self._point_array.SetArray(self._tmp_point_array, 1 * self._num_n2 * self._num_n1 * 3, 1)
        point_set = vtk.vtkPoints()
        point_set.SetData(self._point_array)

        patch_structured_grid = vtk.vtkStructuredGrid()
        patch_structured_grid.SetDimensions(1, self._num_n2, self._num_n1)
        patch_structured_grid.SetPoints(point_set)
        patch_structured_grid.GetPointData().AddArray(self._point_data_array)
        patch_structured_grid.GetPointData().SetActiveScalars("Scalars")

        return patch_structured_grid

    slice = block.sliceToStructuredGrid3([200])

    lut = vtk.vtkLookupTable()
    lut.SetNumberOfColors(256)
    lut.SetRange(0, 7000)
    lut.Build()

    mapper = vtk.vtkDataSetMapper()
    mapper.SetInputData(slice)
    mapper.SetLookupTable(lut)
    mapper.SetScalarRange(0, 7000)

    actor = vtk.vtkActor()

    polyProperty = vtk.vtkProperty()
    polyProperty.SetInterpolationToPBR()
    actor.SetProperty(polyProperty)
    actor.SetMapper(mapper)

    renderer = vtk.vtkRenderer()
    renderer.UseFXAAOn()
    renderer.GetUseFXAA()
    render_window = vtk.vtkRenderWindow()
    render_window.AddRenderer(renderer)
    render_window_interactor = vtk.vtkRenderWindowInteractor()
    render_window_interactor.SetRenderWindow(render_window)

    renderer.AddActor(actor)
    renderer.ResetCamera() 
    render_window.Render() 
    render_window_interactor.Start() 

```

what should I do to plot the data correctly?

thanks for everyone’s help.