# Error while fining mainimum value on cells extracted along line
**URL:** https://discourse.paraview.org/t/error-while-fining-mainimum-value-on-cells-extracted-along-line/14536
**Category:** ParaView Support
**Tags:** vtk
**Created:** [May 2, 2024, 4:29am UTC](https://discourse.paraview.org/t/error-while-fining-mainimum-value-on-cells-extracted-along-line/14536 "2024-05-02T04:29:43Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@h1773](https://discourse.paraview.org/u/h1773)
#### Post date: [May 2, 2024, 4:29am UTC](https://discourse.paraview.org/t/error-while-fining-mainimum-value-on-cells-extracted-along-line/14536/1 "2024-05-02T04:29:43Z")
Hi i am extracting cells along a line and trying to find minimum value of a quantity on extracted cell but it is showing error. using paraview 5.12.
Below the error is shown. Any suggestions?
```auto
**Error: Failed to evaluate Expression '(density == min(density))'. The following exception stack should provide additional developer specific information. This typically implies a malformed expression. Verify that the expression is valid.**
**Warning: In vtkPythonSelector.cxx, line 104**
**vtkPythonSelector (000002C0E9199760): Could not invoke 'python_selector.execute()'**
**Traceback (most recent call last):**
**File "C:\Program Files\ParaView 5.12.0\bin\Lib\site-packages\paraview\detail\python_selector.py", line 80, in execute**
**maskArray = calculator.compute(inputs, query, ns=elocals)**
**File "C:\Program Files\ParaView 5.12.0\bin\Lib\site-packages\paraview\detail\calculator.py", line 167, in compute**
**retVal = eval(subEx, globals(), mylocals)**
**File "", line 1, in **
**File "C:\Program Files\ParaView 5.12.0\bin\Lib\site-packages\vtkmodules\numpy_interface\algorithms.py", line 394, in min**
**return _global_func(MinImpl(), array, axis, controller)**
**File "C:\Program Files\ParaView 5.12.0\bin\Lib\site-packages\vtkmodules\numpy_interface\algorithms.py", line 179, in _global_func**
**res = impl.serial_composite(array, axis)**
**File "C:\Program Files\ParaView 5.12.0\bin\Lib\site-packages\vtkmodules\numpy_interface\algorithms.py", line 382, in serial_composite**
**res = _apply_func2(algs.min, array, (axis,))**
**File "C:\Program Files\ParaView 5.12.0\bin\Lib\site-packages\vtkmodules\numpy_interface\algorithms.py", line 41, in _apply_func2**
**res.append(func(a, *args))**
**File "C:\Program Files\ParaView 5.12.0\bin\Lib\site-packages\vtkmodules\numpy_interface\internal_algorithms.py", line 423, in min**
**ans = numpy.min(narray, axis)**
**File "C:\Program Files\ParaView 5.12.0\bin\Lib\site-packages\numpy\core\fromnumeric.py", line 2953, in min**
**return _wrapreduction(a, np.minimum, 'min', axis, None, out,**
**File "C:\Program Files\ParaView 5.12.0\bin\Lib\site-packages\numpy\core\fromnumeric.py", line 86, in _wrapreduction**
**return reduction(axis=axis, out=out,**passkwargs)**
**File "C:\Program Files\ParaView 5.12.0\bin\Lib\site-packages\numpy\core\_methods.py", line 45, in _amin**
**return umr_minimum(a, axis, None, out, keepdims, initial, where)**
**ValueError: zero-size array to reduction operation minimum which has no identity**
**Generic Warning: In vtkSelection.cxx, line 753**
**No values to evaluate because there was an error in the selection evaluator.**
**ERROR: In vtkExecutive.cxx, line 730**
**vtkPVCompositeDataPipeline (000002C0CBE89450): Algorithm vtkPVExtractSelection (000002C0A6210690) returned failure for request: vtkInformation (000002C0F1BCA860)**
**Debug: Off**
**Modified Time: 24824554**
**Reference Count: 1**
**Registered Events: (none)**
**Request: REQUEST_DATA**
**FORWARD_DIRECTION: 0**
**ALGORITHM_AFTER_FORWARD: 1**
**FROM_OUTPUT_PORT: 0**
```
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [May 2, 2024, 7:52am UTC](https://discourse.paraview.org/t/error-while-fining-mainimum-value-on-cells-extracted-along-line/14536/2 "2024-05-02T07:52:11Z")
Please share your data