# ActiViz/C# can't create a new vtkDataArray
**URL:** https://discourse.vtk.org/t/activiz-c-cant-create-a-new-vtkdataarray/1170
**Category:** Support
**Created:** [June 18, 2019, 10:52pm UTC](https://discourse.vtk.org/t/activiz-c-cant-create-a-new-vtkdataarray/1170 "2019-06-18T22:52:43Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@lucasouto](https://discourse.vtk.org/u/lucasouto)
#### Post date: [June 18, 2019, 10:52pm UTC](https://discourse.vtk.org/t/activiz-c-cant-create-a-new-vtkdataarray/1170/1 "2019-06-18T22:52:43Z")
Hi,
I’m trying to visualize a scalar field on an unstructured grid. I already managed to build and visualize an vtkUnstructuredGrid where Points and Cells where defined. Now I want to “plot” a scalar field on that grid…
For this, I think the easiest way is to do the following:
```
myVtkUnstructuredGrid.GetPointData().SetScalars(myScalarData);
```
The problem is ‘myScalarData’ needs to be an vtkDataArray. However I cannot create a new instance of this object. I tried the following, and they all give errors:
```
vtkDataArray myScalarData = new vtkDataArray();
vtkDataArray myScalarData = vtkDataArray.New();
vtkDataArray myScalarData = (vtkDataArray)vtkObject.New();
```
What am I doing wrong?
---
### Author:  [@cory.quammen](https://discourse.vtk.org/u/cory.quammen)
#### Post date: [June 19, 2019, 1:55am UTC](https://discourse.vtk.org/t/activiz-c-cant-create-a-new-vtkdataarray/1170/2 "2019-06-19T01:55:08Z")
`vtkDataArray` is a pure abstract superclass of the type-specific data arrays such as `vtkFloatArray`, `vtkDoubleArray`, etc., hence you cannot instantiate it. Create one of these array type subclasses instead, and you should have better luck.
---
### Author:  [@lucasouto](https://discourse.vtk.org/u/lucasouto)
#### Post date: [June 19, 2019, 9:10am UTC](https://discourse.vtk.org/t/activiz-c-cant-create-a-new-vtkdataarray/1170/3 "2019-06-19T09:10:48Z")
Thank you so much, that worked.
---
### Author:  [@cory.quammen](https://discourse.vtk.org/u/cory.quammen)
#### Post date: [June 19, 2019, 1:58pm UTC](https://discourse.vtk.org/t/activiz-c-cant-create-a-new-vtkdataarray/1170/4 "2019-06-19T13:58:42Z")
You are welcome 🙂