# Scaling problem

**URL:** https://community.freefem.org/t/scaling-problem/3127
**Category:** General Discussion
**Created:** [April 21, 2024, 3:42pm UTC](https://community.freefem.org/t/scaling-problem/3127 "2024-04-21T15:42:57Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![Wilkinsonad01](https://avatars.discourse-cdn.com/v4/letter/w/f14d63/32.png) [@Wilkinsonad01](https://community.freefem.org/u/Wilkinsonad01)
#### Post date: [April 21, 2024, 3:42pm UTC](https://community.freefem.org/t/scaling-problem/3127/1 "2024-04-21T15:42:57Z")

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Hi all,  
I have ran my code to simulate cell growth diffusing a cross a thin rectangular domain of length 0.6 with a initial condition of c = exp(-75 x) over time t = 9.8. This seems to work perfectly fine. but when I scale the model down to a domain length 0.06, t = 0.98 and c = exp(-750 x), I get errors saying there is a singular matrix.

dt was also scaled from dt = 0.002 to dt = 0.0002

does anyone know why this might be and how to fix it?

thanks

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### Author: ![frederichecht](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.freefem.org/frederichecht/32/15_2.png) [@frederichecht](https://community.freefem.org/u/frederichecht)
#### Post date: [April 26, 2024, 4:25pm UTC](https://community.freefem.org/t/scaling-problem/3127/2 "2024-04-26T16:25:27Z")

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I think exp(-750 x) will be 0 and you system because crazy