**** EXAMPLE 2
*    Creation of a small test pattern and projection data with execution of
*    a user-defined reconstruction algorithm and analysis.
*    
CREATE
Example 2,  A simple test pattern and projection data
SPECTRUM MONOCHROMATIC with energy at 75 KeV
OBJECTS   cx    cy    u     v     ang   den
ELIP      0.00  0.00  0.90  0.90  0.00  2.50
ELIP      0.00  0.00  0.80  0.60  0.00 -1.25
ELIP      0.00  0.00  0.21  0.25  0.00  0.10
LAST  1.00
PHANTOM AVERAGE 1 point for estimating pixel density
number of elements is 31  Size of a pixel is 0.07
RAYSUM AVERAGE 1 line for estimation of ray sum with weight
    1
GEOMETRY
PARALLEL UNIFORM LINE
RAYS USER-defined 63 rays per projection at spacing 0.05
ANGLES 30  EQUAL SPACING between the first and last angles which are
    0.0    174.0
MEASUREMENT PERFECT
BACKGROUND absorption is 0.0
RUN
*
PICTURE TEST
*
PROJECTION REAL
*
MODE LOWER constraint set at 0.0  UPPER constraint set at 2.5
*
SELECT USER RAYSEQ
STEP projections by 10 and rays by 1
*
STOP TERMINATION VARIANCE at 0.01
*
EXECUTE AVERAGE ART SMOOTH
Example 2a  underrelaxed art4 with variable tolerance
smoothing threshold is 0.2  Weights are 2.25 1.5 1.0
111111111111111111111111111111111111111111111111111
ART4  RELAXATION CONSTANT = 0.025  TOLERANCE VARIABLE decreasing
CONSTRAINT BOUND CONRELAX CONSTANT = 0.5 NOMLIZE at each iteration
*
STOP ITERATIONS = 30
*
EXECUTE ALP1
Example 2b  underrelaxed art with extrapolation
*
* Reset mode to unconstrained
MODE
*
EVALUATE RESOLUTION
Example 2a  underrelaxed art4
WHOLEPIC
2222222222222222222222222222222222222222
*
LINES COLUMNS 15 and 18 are to be printed
1         1         1         1
*
END