QTR-Quadtone RIP

Hi,

On occasions, I have managed to get Sergei Antonov's Pulse Reader
utility to scan spot readings and 21 step scales.

I am trying to modify a profile from the files section for use with a
different ink/paper combination by linearizing with the following L
values, or that is what I believe them to be, from scanning a 21 step
TIF RGB file:

18.94
20.16
26.21
31.71
38.82
43.20
46.79
49.34
52.63
56.17
59.93
63.21
66.60
69.99
73.53
76.80
80.34
83.89
87.37
91.07
95.28

However, I get rhe following message:  "Invalid linearize curve - not
constantly increasing.  Curve Creation failed."

Does this mean that every step should increase by the same amount?  If
so I do not understand the point.  If, however, it means that the
value in each step should be greater than the previous step, why does
this set of figures not work.  The following set does!

19.50
21.15
23.47
26.76
30.37
33.82
38.02
40.62
43.08
46.01
51.59
60.09
66.13
69.19
72.48
75.80
79.35
83.38
87.65
91.51
95.17


Can someone enlighten me please?


Colin