# Append Attributes filter only keeping one data array

**URL:** https://discourse.paraview.org/t/append-attributes-filter-only-keeping-one-data-array/10118
**Category:** ParaView Support
**Created:** [August 8, 2022, 3:44pm UTC](https://discourse.paraview.org/t/append-attributes-filter-only-keeping-one-data-array/10118 "2022-08-08T15:44:05Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![atompaul](https://discourse.paraview.org/user_avatar/discourse.paraview.org/atompaul/32/9722_2.png) [@atompaul](https://discourse.paraview.org/u/atompaul)
#### Post date: [August 8, 2022, 3:44pm UTC](https://discourse.paraview.org/t/append-attributes-filter-only-keeping-one-data-array/10118/1 "2022-08-08T15:44:05Z")

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ParaView for Mac 5.10.1

I have two XDMF files, each containing a unique data array. The first one contains an array “t”, and the second contains the array “domain\_labels”.

I am trying to combine them using the Append Attributes filter. I select both inputs, apply an AppendAttributes filter, but the result only contains a single data array. It seems to contain the array of the object I select first. If I try clicking “Change Input”, both the sources are selected as I expect. I try reselecting but no matter what I do, it only contains the data from the object I select first.

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### Author: ![mwestphal](https://discourse.paraview.org/user_avatar/discourse.paraview.org/mwestphal/32/17_2.png) [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [August 9, 2022, 2:08am UTC](https://discourse.paraview.org/t/append-attributes-filter-only-keeping-one-data-array/10118/2 "2022-08-09T02:08:22Z")

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Hi @atompaul ,

AppendAttributes requires both sources to have the same number of cells and points. Is that the case here ?

Best,