# How to force a predicted Flux model to give output numbers \> 0

**URL:** <https://discourse.julialang.org/t/how-to-force-a-predicted-flux-model-to-give-output-numbers-0/106623>\
**Category:** General Usage\
**Tags:** question, flux\
**Created:** [November 23, 2023, 11:56am UTC](https://discourse.julialang.org/t/how-to-force-a-predicted-flux-model-to-give-output-numbers-0/106623 "2023-11-23T11:56:32Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![EL-Bakkali-Jaafar](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/el-bakkali-jaafar/32/21412_2.png) [@EL-Bakkali-Jaafar](https://discourse.julialang.org/u/EL-Bakkali-Jaafar)\
**Post date:** [November 23, 2023, 11:56am UTC](https://discourse.julialang.org/t/how-to-force-a-predicted-flux-model-to-give-output-numbers-0/106623/1 "2023-11-23T11:56:32Z")

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Hi everybody,  
I have some inputs and outputs data for training a model using Flux package. These data by nature should be strictly positive.The training phase was done successfully however when I am trying to check it validity by using some test data, some of them were OK but others give negative values. How can I force the model to only outputted positive values.  
Thanks and greeting.

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**Author:** ![sylvaticus](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/sylvaticus/32/203883_2.png) [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Post date:** [November 23, 2023, 12:26pm UTC](https://discourse.julialang.org/t/how-to-force-a-predicted-flux-model-to-give-output-numbers-0/106623/2 "2023-11-23T12:26:37Z")

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Use as activation function of the last layer a function whose domain is in R+, most notably the `Relu` function.

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**Author:** ![EL-Bakkali-Jaafar](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/el-bakkali-jaafar/32/21412_2.png) [@EL-Bakkali-Jaafar](https://discourse.julialang.org/u/EL-Bakkali-Jaafar)\
**Post date:** [November 24, 2023, 8:21am UTC](https://discourse.julialang.org/t/how-to-force-a-predicted-flux-model-to-give-output-numbers-0/106623/3 "2023-11-24T08:21:49Z")

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Thank you a lot for your prompt reply.