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POLYWARP question.



Hi everybody,

this is regarding POLYWARP function, in particular DEGREE argument. As far as I
understood by the Online Help, POLYWARP accepts the following polynomial models
depending on the value of DEGREE:

DEGREE = 0:
Xi = kx00
Yi = ky00

DEGREE = 1:
Xi = kx00 + kx01 Xo  +  kx10 Yo  +  kx11 XoYo

Yi = ky00 + ky01 Xo  +  ky10 Yo  +  ky11 XoYo
 

DEGREE = 2:
Xi = kx00 + kx01 Xo  +  kx10 Yo  +  kx11 XoYo + kx02Xo2+ kx20Yo2 + kx12 Xo2 Yo  + kx21XoYo2+ kx22 Xo2 Yo2

Yi = ky00 + ky01 Xo  +  ky10 Yo  +  ky11 XoYo + ky02Xo2+ ky20Yo2 + ky12 Xo2 Yo  + ky21XoYo2+ ky22 Xo2 Yo2
 

This is fine, but poor in flexibility: what happens if I want to consider a model like this, which acounts for 1st. degree crossed XY terms and 2nd. degree in X and Y?

Xi = kx00 + kx01 Xo  +  kx10 Yo  +  kx11 XoYo + kx02Xo2+ kx20Yo2
Yi = ky00 + ky01 Xo  +  ky10 Yo  +  ky11 XoYo + ky02Xo2+ ky20Yo2
 

Does anybody know any implementation/patch of POLYWARP which permits more freedom in considering
coeficients to obtain?
 

Thanks in advance,

Octavi.

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Octavi Fors Aldrich

Departament d'Astronomia i Meteorologia
Facultat de Fisica
Avgda. Diagonal 647
08028 Barcelona
SPAIN

Telf: 34-934021122
Fax:  34-934021133
e-mail: octavi@fajnm1.am.ub.es

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