# Setting the extents for OverlappingAMR data set

**URL:** https://discourse.paraview.org/t/setting-the-extents-for-overlappingamr-data-set/1084
**Category:** Development
**Created:** [December 26, 2018, 10:44pm UTC](https://discourse.paraview.org/t/setting-the-extents-for-overlappingamr-data-set/1084 "2018-12-26T22:44:07Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![Aandreyev](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/a/34f0e0/32.png) [@Aandreyev](https://discourse.paraview.org/u/Aandreyev)
#### Post date: [December 26, 2018, 10:44pm UTC](https://discourse.paraview.org/t/setting-the-extents-for-overlappingamr-data-set/1084/1 "2018-12-26T22:44:07Z")

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Hello all,

I am writing a parallel reader for our in house AMR data. I am close, but I have some confusion with the request information routine and it’s requirement for “UPDATE\_EXTENT” portion.

I am a bit confused what to put for the 6 numbers i\_lo, j\_lo,k\_lo, i\_hi, j\_hi, k\_hi since an overlapping AMR data set has a lot of Uniform Grids defined by AMR boxes. I understand the extents for each of the grids that make up an vtkOverlappingAMR data set, but how do I define only one?

Thanks in advance,  
Andrey