CASTI-89 TITANIUM · CALC89
CubicReg
Fits a cubic polynomial y=a·x^3+b·x^2+c·x+d to data with least squares regression. The results are stored in stat variables such as stat.RegEqn.
Syntax
CubicReg X,Y[,[Freq][,Category,Include]]
- Group
- Statistics
- Arguments
- Takes the x list, the y list and optional frequency, category and include lists.
- Availability
- Included
- Menu path
- MATH ▸ Statistics ▸ CALC ▸ CubicReg
Example
| Input | Result |
|---|---|
| CubicReg {0,1,2,3,4},{0,1,8,27,64}:stat.RegEqn | 1.0·x3 |
Typing CubicReg {0,1,2,3,4},{0,1,8,27,64}:stat.RegEqn on the home screen and pressing ENTER returns 1.0·x3.
Keystrokes on the TI-89 Titanium
2NDMATH6▶6
The same key sequence inserts CubicReg in Calc89, and the AI tutor shows it step by step on the on-screen keypad.
Related commands
- ExpRegFits an exponential model y=a·b^x to data with least squares regression.
- FTest_2SampPerforms a two sample F test that compares the variances of two populations.
- LinRegBxFits a line y=a+b·x to data with least squares regression.
- LinRegMxFits a line y=m·x+b to data with least squares regression.
- LinRegtIntervalsComputes confidence intervals for a linear regression, for the slope or for a predicted response.
- LinRegtTestPerforms a t test on the slope of a linear regression and the correlation of the data.
- LnRegFits a logarithmic model y=a+b·ln(x) to data with least squares regression.
- LogisticFits a logistic growth model y=c/(1+a·ℯ^(−b·x)) to data.