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Such specificity
of variables has allowed to use effectively at the second stage of experiments
the gradient procedure in which moving on all variables of eight-parametrical
conformity measure is carried out simultaneously and basically is independent.
During searching delays are possible (misses of steps on some variables)
if parameters with higher priority were not arranged yet. In final variant
the following system of priorities was used: (+, A), (P1, P2), (D), (B1,
B2, =) where - "+" and "=" designate moving in cross and longitudinal directions
accordingly. The step on any variable increases half (with the count
of restriction on maximum value - see further) if the it is executed in
the same direction, as previous, and decreases otherwise. Thus it is considered,
that those variables were arranged, the step on which became less, than
1/4 from the maximum admissible value on the given variable.

The last values
were chosen from the most common reasons so that as a result of each
step the new approximating segment not too overstepped the bounds of old
onethe. Steps in a longitudinal direction (and on length of the branches)
were limited to value B/2, and in cross - D/2. Steps on the angle and curvature
should not oscillate ends of the segment on value bigger than D/2, i.e.
A*MAX(B1, B2)/0.7 and
P * (B/0.7)/2 should not exceed D/2. In order to prevent* *discretization
*disclosures* of analysed contours, the value of parameter D was
limited from below to the value ranging 0.5 - 2.5 distances between adjacent
points of the raster. From above parameter D was limited by value B/2.

Particularly
such restrictions are organized so, that at the approach to one of them
it is authorized to make the following step only on half of the distance
before this restriction. It simply enough ensures a possibility of increase
of a step if a necessity of movement in the opposite direction exists.
Initial steps on separate components were chosen equal to the half of
their greatest possible values. Thus initial values of parameters B and
D were accepted equal 10 and 4 accordingly, and as much as the possible
admissible step value on D equal 0.5. Search procedure of the next conformity
measure maximum stopped when steps on all variables became smaller, than 0.2
of their maximum possible admissible values.

As a rule, search
of the maximums corresponding to contour segments required on the average
60-80 steps on theof declination angle and position in the cross direction
at 8-12 steps in the longitudinal direction.