NGC6864
 7 iterations.
Chebyshev coeffients a(0)T_0(u)+a(1)T_1(u)+..., where u is log (r/arcsec) mapped to [-1,1]
 a(0)=    20.434 +-  0.156
 a(1)=     5.927 +-  0.285
 a(2)=     1.166 +-  0.228
 a(3)=     0.317 +-  0.169
 a(4)=     0.174 +-  0.125
Power-of-x coeffients a(0)+a(1)x+a(2)x^2+..., where x=1+(r/r_c), r_c=0.83
 a(0)=     5.3101
 a(1)=     0.6508
 a(2)=     1.3579
 a(3)=    -0.5272
 a(4)=     0.0845
log r(arcsec)   mu_V    mu_V(fitted)  residual   weight  data set