# Additive Selection not working for vtkScatterPlotMatrix

**URL:** <https://discourse.vtk.org/t/additive-selection-not-working-for-vtkscatterplotmatrix/15567>\
**Category:** Support\
**Created:** [May 5, 2025, 12:51pm UTC](https://discourse.vtk.org/t/additive-selection-not-working-for-vtkscatterplotmatrix/15567 "2025-05-05T12:51:13Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![roy](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/r/4da419/32.png) [@roy](https://discourse.vtk.org/u/roy)\
**Post date:** [May 5, 2025, 12:51pm UTC](https://discourse.vtk.org/t/additive-selection-not-working-for-vtkscatterplotmatrix/15567/1 "2025-05-05T12:51:14Z")

</div>

I’m rendering a scatterplot matrix in VTK, but the additive selection ([VTK: vtkScatterPlotMatrix Class Reference](https://vtk.org/doc/nightly/html/classvtkScatterPlotMatrix.html#afefa42e10b61ae8d7e1c66ef370d8827)) is not working as it should.

Only when I change the selection method for the big chart to SELECTION\_PLOTS using:

```auto
matrix->GetMainChart()->SetSelectionMethod(vtkChart::SELECTION_PLOTS);
matrix->GetMainChart()->SetSelectionMode(vtkContextScene::SELECTION_ADDITION);

```

it seems to work ONLY for the big plot whereas I want the corresponding selected points to be selected in the smaller plots as well like they get selected in the normal selection mode.

Any ideas on how I can fix this issue?