# Calculator using python math functions
**URL:** https://discourse.paraview.org/t/calculator-using-python-math-functions/1004
**Category:** ParaView Support
**Created:** [December 5, 2018, 2:26pm UTC](https://discourse.paraview.org/t/calculator-using-python-math-functions/1004 "2018-12-05T14:26:05Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@aharvey](https://discourse.paraview.org/u/aharvey)
#### Post date: [December 5, 2018, 2:26pm UTC](https://discourse.paraview.org/t/calculator-using-python-math-functions/1004/1 "2018-12-05T14:26:05Z")
I need to calculate a new variable in my dataset, but I need access to math functions that aren’t available in the calculator filter. Specifically, I want to use the python math.erf function. Is there any way I can access this?
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [December 5, 2018, 2:38pm UTC](https://discourse.paraview.org/t/calculator-using-python-math-functions/1004/2 "2018-12-05T14:38:52Z")
Calculator is not compatible with python. You want to use **Python Calculator** filter.
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### Author:  [@aharvey](https://discourse.paraview.org/u/aharvey)
#### Post date: [December 5, 2018, 2:41pm UTC](https://discourse.paraview.org/t/calculator-using-python-math-functions/1004/3 "2018-12-05T14:41:18Z")
Well yes, but how can I access other functions in the python calculator? I’m thinking I need something like an “import math” command, but I don’t know how to do that in that filter. I know I can load libraries with programmable filter, but I don’t know how to setup a new variable using it.
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [December 5, 2018, 10:46pm UTC](https://discourse.paraview.org/t/calculator-using-python-math-functions/1004/4 "2018-12-05T22:46:47Z")
You have access to the following methods :
>
As well as all numpy using `np.`
sadly this does not contain erf, nor math.
I suppose this importing math (and scipy) should be a good idea.
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### Author:  [@aharvey](https://discourse.paraview.org/u/aharvey)
#### Post date: [December 6, 2018, 1:27pm UTC](https://discourse.paraview.org/t/calculator-using-python-math-functions/1004/5 "2018-12-06T13:27:03Z")
I was able to get done what I wanted through the programmable filter. That allowed me to import math, which gave me access to math.erf, which in turn allowed me to define a lognormal CDF (my real end goal). If in the future math and scipy.stats to the python calculator can be added, that would be great!