INTERP L1,L2,L3,L4,K
where K is a label of a mask line of the form
XXXXX XXXX YY.YYY XX YYY.YY
interpolates columns denoted by Y masks by linear regression analysis
using X columns as regressors. If there are no X columns or only one
X column appears, the Y columns are interpolated by polynomial regres-
sion. In this case the degree m of the polynomial is given by the
specification DEGREE=m. Default is DEGREE=1.
The source data with complete X and Y values is given on lines L1-L2.
The interpolated (and extrapolated) Y values will be computed on
lines L3-L4 using given X values on the same lines.
In polynomial regression without X columns, L-L1+1 where L is the
current line number, is the basic regressor. In this case it is typical
that L3=L2+1.
Examples on the next page!
57 *INTERP A,B,C,D,E
58 E XX XX YYY.Y YYY.YY
59 A 10 5 15.5 25
60 * 0 3 3.5 3
61 * 7 4 11.5 18
62 B 2 -5 -2.5 -1
63 C 7 4 11.5 18.00
64 * 3 3 6.5 9.00
65 D 11 3 14.5 25.00
66 *.............................................................................................
67 *INTERP CUR+2,CUR+4,CUR+5,CUR+7,CUR+1 / DEGREE=2
68 * YYY
69 * 1
70 * 4
71 * 9
72 * 16
73 * 25
74 * 36
T = More information on operations for tables
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