@Carl Love 

Thanks so much

@Carl Love 

Thanks.

I have been provided an Excel file.

Please explain more about the process of filter out the Y column.

BOOK1.xlsx

@Carl Love 

Thanks 

I combined them as attached figure and used from previous code but I encounter with this error!

Error, (in Statistics:-LinearFit) unable to store '1/"Y"' when datatype=float[8]
 

Thanks

3dModelFit.mw

@Carl Love 

I want to obtain one optimal solution or surface that covers four group data Simultaneous.

Thanks

@Carl Love 

How I can do the same procedure for 4 separate groups data provided in the attached excel file.

Best

PLOTfitting.xls

@Carl Love 

Thanks so much

@Carl Love 

Thanks.

I have not been used ExcelTolls before, but I am ready to use it if you help.

Thanks

@Carl Love 

Thanks so much.

Yes, I have a theoretical model that has been fit to this data.

Z=(A+B*x)/(x+y), where A and B are constants.

Everything that works for this data is sufficient or maybe the smooth plot of the surface!!

Please guide me for available things that Maple can do.

Thanks

@Carl Love 

Thank so much.

I need surface i.e.,  z ~ f(x,y).

Thanks 

@Carl Love 

Thanks

I applied your comments in the attached file. How I can plot functions  p,q,r,s, versus time.

Best

equations2.mw

@Kitonum 

Thanks 

How I can write the result obtained in the final equation, i.e., Eq (l__1) as the format in which arrange according to the order of u__2  to reach a close and a simple form.

For example, in attached figure there is a sample for the result arranged versus x2 and y2, but in my file only there is u_2 as a single parameter

A (u_2)^5+B (u_2)^4+C (u_2)^3+D (u_2)^2+E (u_2)+....

@tomleslie 

Thanks my problem is solved.

Best

@acer 

Thanks so much.

Best,

Iman

@acer 

TEMPThanks,

But when I copy it into mathtype equation, the nations has many problems. please see attached file below.

@acer 

Sorry....end.mw
 

Download end.mw