# Output equation for a generated surface in Plotly

**URL:** <https://community.plotly.com/t/output-equation-for-a-generated-surface-in-plotly/48229>\
**Category:** 📊 Plotly Python\
**Created:** [December 15, 2020, 2:25pm UTC](https://community.plotly.com/t/output-equation-for-a-generated-surface-in-plotly/48229 "2020-12-15T14:25:35Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![rberdon](https://avatars.discourse-cdn.com/v4/letter/r/919ad9/32.png) [@rberdon](https://community.plotly.com/u/rberdon)\
**Post date:** [December 15, 2020, 2:25pm UTC](https://community.plotly.com/t/output-equation-for-a-generated-surface-in-plotly/48229/1 "2020-12-15T14:25:36Z")

</div>

Hello Plotly Community,

I am currently working with some 3D data points and will create a surface plot. The question I have is, can you output an explicit equation for the surface generated by Plotly? I would like to be able to estimate a given Z value given any X or Y value within the parameter space. Please let me know if you have any thoughts.

Thanks,  
Randall Berdon

---

<div class="post-metadata">

**Author:** ![empet](https://avatars.discourse-cdn.com/v4/letter/e/977dab/32.png) [@empet](https://community.plotly.com/u/empet)\
**Post date:** [December 15, 2020, 6:51pm UTC](https://community.plotly.com/t/output-equation-for-a-generated-surface-in-plotly/48229/2 "2020-12-15T18:51:08Z")

</div>

@rberdon

Could you give more details on your data?

Are you defining a `go.Surface` based on x, y, z resulted from the discretization of an explicitly given surface, of equation z=f(x,y) or you have only the above arrays x, y, z acquired from measurements?

---

<div class="post-metadata">

**Author:** ![rberdon](https://avatars.discourse-cdn.com/v4/letter/r/919ad9/32.png) [@rberdon](https://community.plotly.com/u/rberdon)\
**Post date:** [December 15, 2020, 7:07pm UTC](https://community.plotly.com/t/output-equation-for-a-generated-surface-in-plotly/48229/3 "2020-12-15T19:07:25Z")

</div>

Thank you for responding @empet. I am defining a go.Surface based on x, y, z from arrays acquired from measurements. I want to take these measured points create a surface that fits these points and identify the equation of the fit surface. I am wondering if I can somehow output from Plotly directly the explicit equation for a surface that is created so I will know the z value of any given point.

Best,  
Randall Berdon

---

<div class="post-metadata">

**Author:** ![empet](https://avatars.discourse-cdn.com/v4/letter/e/977dab/32.png) [@empet](https://community.plotly.com/u/empet)\
**Post date:** [December 15, 2020, 7:49pm UTC](https://community.plotly.com/t/output-equation-for-a-generated-surface-in-plotly/48229/4 "2020-12-15T19:49:50Z")

</div>

@rberdon

Unfortunately you cannot get the surface equation. Not only Plotly cannot derive it, but I don’t think you can find a graphic library that returns the equation of a discrete surface.