Chapter 12: Statistics 309
LinReg(ax+b) [Xlistname,Ylistname,freqlist,regequ]
QuadReg (ax
QuadReg (axQuadReg (ax
QuadReg (ax2+bx+c)
+bx+c)+bx+c)
+bx+c)
QuadReg (quadratic regression) fits the second-degree polynomial y=ax2+bx+c to the
data. It displays values for a, b, and c; when DiagnosticOn is set, it also displays a value
for R2. For three data points, the equation is a polynomial fit; for four or more, it is a
polynomial regression. At least three data points are required.
QuadReg [Xlistname,Ylistname,freqlist,regequ]
CubicReg—(a
CubicReg—(aCubicReg—(a
CubicReg—(ax
xx
x3+b
+b+b
+bx
xx
x2+c
+c+c
+cx
xx
x+d)
+d)+d)
+d)
CubicReg (cubic regression) fits the third-degree polynomial y=ax3+bx2+cx+d to the
data. It displays values for a, b, c, and d; when DiagnosticOn is set, it also displays a
value for R2. For four points, the equation is a polynomial fit; for five or more, it is a
polynomial regression. At least four points are required.
CubicReg [Xlistname,Ylistname,freqlist,regequ]
QuartReg—(a
QuartReg—(aQuartReg—(a
QuartReg—(ax
xx
x4+b
+b+b
+bx
xx
x3+c
+c+c
+cx
xx
x2+ dx+e)
+ dx+e)+ dx+e)
+ dx+e)
QuartReg (quartic regression) fits the fourth-degree polynomial y=ax4+bx3+cx2+dx+e to
the data. It displays values for a, b, c, d, and e; when DiagnosticOn is set, it also displays
a value for R2. For five points, the equation is a polynomial fit; for six or more, it is a
polynomial regression. At least five points are required.