# How to Overlay Observed Data on NLME Simulation Plot

**URL:** <https://forum.certara.com/t/how-to-overlay-observed-data-on-nlme-simulation-plot/4283>\
**Category:** Phoenix\
**Created:** [July 9, 2025, 9:58pm UTC](https://forum.certara.com/t/how-to-overlay-observed-data-on-nlme-simulation-plot/4283 "2025-07-09T21:58:06Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Yook\_Noh](https://avatars.discourse-cdn.com/v4/letter/y/e480ec/32.png) [@Yook\_Noh](https://forum.certara.com/u/Yook_Noh)\
**Post date:** [July 9, 2025, 9:58pm UTC](https://forum.certara.com/t/how-to-overlay-observed-data-on-nlme-simulation-plot/4283/1 "2025-07-09T21:58:06Z")

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Hi there,  
I’m currently working on an NLME simulation job. I used a mixed-effects model to simulate the steady-state PK profile and reviewed the **Ind Simulation** plot in the output. The plot shows only the simulated concentrations, not the observed data.

 ![NLME sim plot 1](https://us1.discourse-cdn.com/certara/original/2X/e/e6677871826c991f55f1f58021cae767c3f3238e.png)

I’d like to compare the **simulated concentrations** with the **observed concentrations** by overlaying them in the same plot, but I couldn’t find an option to do this within the NLME interface.  
Could you please guide me on how to incorporate the observed data points into the simulation plot? Any help would be greatly appreciated.

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**Author:** ![Samer\_Mouksassi](https://avatars.discourse-cdn.com/v4/letter/s/ce7236/32.png) [@Samer\_Mouksassi](https://forum.certara.com/u/Samer_Mouksassi)\
**Post date:** [July 10, 2025, 11:30pm UTC](https://forum.certara.com/t/how-to-overlay-observed-data-on-nlme-simulation-plot/4283/2 "2025-07-10T23:30:50Z")

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you will have to do a separate plot using the buitl in xy plot object where you add another source for data which has the observed dat and the simulation table for the simualted profiles

 ![image](https://us1.discourse-cdn.com/certara/original/2X/4/4b9aad576de93539b81285898e97ba801590ed5e.jpeg)  
 ![image](https://us1.discourse-cdn.com/certara/original/2X/1/17f9daa6a5cf457004f7bf2d36ec387d4c312ba2.png)

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**Author:** ![Yook\_Noh](https://avatars.discourse-cdn.com/v4/letter/y/e480ec/32.png) [@Yook\_Noh](https://forum.certara.com/u/Yook_Noh)\
**Post date:** [July 11, 2025, 1:14am UTC](https://forum.certara.com/t/how-to-overlay-observed-data-on-nlme-simulation-plot/4283/3 "2025-07-11T01:14:06Z")

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Dear Samer,

Oh, I see. Thank you for the method. I’ll use it with another ‘XY Plot’ function.

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**Author:** ![SimonDavis](https://avatars.discourse-cdn.com/v4/letter/s/d9b06d/32.png) [@SimonDavis](https://forum.certara.com/u/SimonDavis)\
**Post date:** [July 18, 2025, 11:38am UTC](https://forum.certara.com/t/how-to-overlay-observed-data-on-nlme-simulation-plot/4283/4 "2025-07-18T11:38:39Z")

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In case you aren’t aware it is very easy to overlay data from different worksheets by using the option to “Add graphs” which when clicked will add additional mapping inputs. Simon.

 ![image](https://us1.discourse-cdn.com/certara/original/2X/f/f56ecab530af3502cdf08b160400ee94c85ffa94.png)

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**Author:** ![Yook\_Noh](https://avatars.discourse-cdn.com/v4/letter/y/e480ec/32.png) [@Yook\_Noh](https://forum.certara.com/u/Yook_Noh)\
**Post date:** [July 18, 2025, 8:27pm UTC](https://forum.certara.com/t/how-to-overlay-observed-data-on-nlme-simulation-plot/4283/5 "2025-07-18T20:27:41Z")

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Thank you, Simon. I didn’t know that function. It is very helpful to use.