Syntax: POLYFIT(X, Y, d)
X = a range representing a row or column vector of
independent variable values
Y = a range representing a row or column vector of
dependent variable values
d = polynomial degree in the range 1 to 10
POLYFIT generates the least squares polynomial fit. The output of this function is the vector of estimated y-values on the left hand side of the above equation. The input vector X and Y must both be row vectors or both column vectors. The output vector will be a row vector if X and Y are row vectors, and a column vector if X and Y are column vectors. The length of the output vector is equal the the length of the input vectors.
Example:
Matrix B1..B5 =
B | |
1 | 1 |
---|---|
2 | 3 |
3 | 3 |
4 | 4 |
5 | 5 |
Matrix C1..C5 =
C | |
1 | 3 |
---|---|
2 | 5 |
3 | 11 |
4 | 18 |
5 | 31 |
POLYFIT(B1..B5, C1..C5, 2) =
3.0857143 |
5.0571429 |
10.314286 |
18.857143 |
30.685714 |
Excel function: N/A