how to find a polynomial?

i have data for x and y values,by using these how to find a polynomial X=0.042672375396118 and Y=-0.17386168 , -0.18001581 , -0.19355754 ,

[Rik]

You have only a single x-value and 3 y-values?

If you have x-y pairs you can use polyfit.

[shahul thaufeek]

but in polyvit i am getting only answers,but my need is polynomial whether we can get polynomial using least square method can u tell me how to use least square method in matlab

[Rik]

Actually you don't get corresponding values from polyfit. You get the parameters. So for a third order polynomial described as y=p1*x^3+p2*x^2+p3*x+p4, polyfit will return a vector p formed by p=[p1 p2 p3 p4];

And it does use the least-squares method, as you can read in the doc.

[Rik]

Please don't use the answer field for comments, nor should you accept an answer if it doesn't solve your question.

If you have three sets of y-values and want to fit a single polynomial to your data, you need to replicate the x-values.

Answer 1

[shahul thaufeek]

Actually I have value like these

data is X value and

other columns are y values

[Image Analyst]

Looks like you figured it out yourself since you've accepted this answer. So I guess there's nothing left for us to answer or help you out with.