# error with function using vtkArrayCalculator

**URL:** https://discourse.vtk.org/t/error-with-function-using-vtkarraycalculator/12526
**Category:** Support
**Created:** [October 24, 2023, 8:16am UTC](https://discourse.vtk.org/t/error-with-function-using-vtkarraycalculator/12526 "2023-10-24T08:16:22Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![Ludo](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/l/5f9b8f/32.png) [@Ludo](https://discourse.vtk.org/u/Ludo)
#### Post date: [October 24, 2023, 8:16am UTC](https://discourse.vtk.org/t/error-with-function-using-vtkarraycalculator/12526/1 "2023-10-24T08:16:22Z")

</div>

Hello everyone,

I’m creating streamline with vtkstreamtracer and in order to create vector from my data I’m using vtkArrayCalculator.

So far the data array name I was using was just a single word without space and had no issue so far.  
Now I would like to handle the possibility to have a data array name that contain space.

I saw that in Paraview this could be achieved by using double quote but in VTK (C#), I have the following error:  
Syntax error: expecting a variable name; see position 5

position 5 is the first double quote.

below is my code.

```auto
string FeatureName = "all";
string Function = "iHat*\"" + FeatureName + "\"+jHat*\"" + FeatureName + "\"+kHat*\"" + FeatureName + "\"";
vtkArrayCalculator Calculator = new vtkArrayCalculator();
Calculator.SetInputData(CellDataToPointData.GetOutput());
Calculator.AddScalarArrayName(FeatureName, 0);
Calculator.SetFunction(Function);
Calculator.SetResultArrayName("Result");
Calculator.Update();

```

Could you please tell my how to fix the issue?  
I really thank you in advance for your help