3d curve fitting for a data set

I have 6 data points in 3d. I need to fit a curve to that points and find the equation of that curve. Figure and matlab code is attached.Figure 3 in the code is the one that I need to fit a curve.

Answer 1

[Prabhan Purwar]

Hi,

I would suggest you to kindly have a look at the Curve Fitting Toolbox it can perform the surface fitting. Use the Curve Fitting App to perform the fitting interactively or see "Fit and Plot a Polynomial Surface" on this documentation page for instructions on how to do it programmatically.

If you don't have Curve Fitting Toolbox, see the "Multiple Regression" section on this documentation page.

If the above doesn't work could you please elaborate upon what you are trying to achieve through code, as it will help us to give an appropriate solution.

Thanks

[Hetti Mudiyanselage Chanuka Bhaggya Gunarathne]

Hi,

Thank you for the reply but in my problem I have to fit a curveto the data points(curve in 3d) not a surface in 3d.

[Prabhan Purwar]

Hi,

In 3D space curve fitting takes place as z=f(x,y) which gives a 3D curve/surface, In order to get the relation in 2 variables, the third variable can be eliminated using a relation between the other two variables.

For example

• Get z=f(x,y) equation for surface
• Get f(x)=y equation from 2D curve fitting
• eliminate the variable of your choice (y in this case)

Thanks

Answer 2

[VIGNESH BALAJI]

@Prabhan Purwar I have a similar question, How do I write a script in matlab without curve fitting tool to fit data of a 3D point as a line ?

[Torsten]

https://stackoverflow.com/questions/2298390/fitting-a-line-in-3d

[VIGNESH BALAJI]

@Torsten I ideally want to generate a catenary curve (2d) to fit a 3D dataset