# How to put function value at a particular location, in the calculator?

**URL:** https://discourse.paraview.org/t/how-to-put-function-value-at-a-particular-location-in-the-calculator/12457
**Category:** ParaView Support
**Created:** [July 6, 2023, 2:34pm UTC](https://discourse.paraview.org/t/how-to-put-function-value-at-a-particular-location-in-the-calculator/12457 "2023-07-06T14:34:16Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![kstar](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/k/59ef9b/32.png) [@kstar](https://discourse.paraview.org/u/kstar)
#### Post date: [July 6, 2023, 2:34pm UTC](https://discourse.paraview.org/t/how-to-put-function-value-at-a-particular-location-in-the-calculator/12457/1 "2023-07-06T14:34:16Z")

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Hi, my original problem involves finding the thickness of fluid jet. I need to find the location of points where the fluid velocity is half the velocity at the axis(y=0). My idea was to perform something like

U = u(xcordn,ycordn) / u(xcordn,0)

, so that the velocity in whole domain is normalised with the velocity at axis, and then later draw a contour line for value 0.5. But I guess we cant give coordinates this way. Is there any way to do this in calculator, or any other idea how to approach this problem?

Thanks