# Sparse Efficiency Warning

**URL:** https://bempp.discourse.group/t/sparse-efficiency-warning/110
**Category:** Bempp
**Created:** [7 December 2021 11:59 UTC](https://bempp.discourse.group/t/sparse-efficiency-warning/110 "2021-12-07T11:59:17Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![Gustavo](https://yyz2.discourse-cdn.com/free1/user_avatar/bempp.discourse.group/gustavo/32/36_2.png) [@Gustavo](https://bempp.discourse.group/u/Gustavo)
#### Post date: [7 December 2021 11:59 UTC](https://bempp.discourse.group/t/sparse-efficiency-warning/110/1 "2021-12-07T11:59:17Z")

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Hi,

I am totally new to BEMPP and I am still figuring out how to do some stuff.

Everytime I ran some code I find here in the Discourse, most of the times I get this warning:

**SparseEfficiencyWarning: splu requires CSC matrix format**

Any hint on how can I solve this?

Thanks in advance,  
Gustavo

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### Author: ![mscroggs](https://yyz2.discourse-cdn.com/free1/user_avatar/bempp.discourse.group/mscroggs/32/3_2.png) [@mscroggs](https://bempp.discourse.group/u/mscroggs)
#### Post date: [7 December 2021 16:30 UTC](https://bempp.discourse.group/t/sparse-efficiency-warning/110/2 "2021-12-07T16:30:47Z")

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This is a warning that scipy gives to warn that it’s changing the format of a sparse matrix. There’s not a lot we can do to avoid this conversion, so you can safely ignore this error.

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### Author: ![Elwin](https://yyz2.discourse-cdn.com/free1/user_avatar/bempp.discourse.group/elwin/32/38_2.png) [@Elwin](https://bempp.discourse.group/u/Elwin)
#### Post date: [29 April 2022 12:50 UTC](https://bempp.discourse.group/t/sparse-efficiency-warning/110/3 "2022-04-29T12:50:27Z")

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In case someone wants to suppress the warning message, use the following code snippet in your script.

```auto
import warnings
warnings.filterwarnings("ignore", message="splu requires CSC matrix format")

```