[R] help with mars output

[Russell Brown]

I need help in interpreting some output of polymars.

The returned model by my command is:

m$model
  pred1    knot1 pred2 knot2       coefs           SE
1     0       NA     0    NA  1.32222163 0.0007806758
2     1       NA     0    NA -0.10904285 0.0006735827
3     1 1.193575     0    NA  1.25396217 0.0205092438
4     1 1.205400     0    NA -0.18020096 0.0261931173
5     1 1.230725     0    NA  0.04709508 0.0118559207
6     1 1.285400     0    NA -0.02593593 0.0097733958
7     1 1.317275     0    NA  0.03516571 0.0177043207


I'm trying to confirm the generated output of mars by manually entering the basis functions into my dataset, What I don't understand is that in the knot1 column there are to rows containing NA.  In the polymars literature I was reading this means that these basis functions are linear.

BF1 = MAX(0, A2 - 1.193575)
BF2 =MAX(0, 1.193575 -  A2)
BF3 = MAX(0, A2 - 1.2054)
BF5 = MAX(0, A2 - 1.230725)
BF7 = MAX(0, A2 - 1.2854)
BF11 = MAX(0, A2 - 1.317275)

RESPONSE = 1.32222163 - 0.10904285 * C2 + 1.25396217 * D2 - 0.18020096 *         E2 + 0.04709508 * F2 - 0.02593593 * G2 + 0.03516571 * H2

On the attached, the CLOSE column is my source data, the ESTIMATE is the column generated by polymars, the PREDICTION column is my formula.

Can I have some help with this please.