...
The function returns the approximated value according to the selected fitting order. Extrapolation outside the x-range is performed according to the selected order of the curve for that dimension. The theoretical maximum order can be calculated using the following example relation:
Least_square_order=ROUND(SQRT(ORCA(TeLiTab_to_be_used#)),0)...
In this example syntax 1 is used, the TeLiTab containing the data is addressed in the Dataslot of the relation.
The syntax is
LEASQ(Pno%, Ndim%, "ColLab$_1" or ColNo%_1,.., "ColLab$_Ndim%" or ColNo%_Ndim%, Xint_1,..,Xint_Ndim%-1, Order%_1,..,Order%_Ndim%-1, [Xtrap%=0,1])
For two dimensional interpolation on a regression line (Order%=1) and a TeLiTab in the Dataslot, the argument sequence is the following:
y = LEASQ(1, 2, "XC", "YC", x, 1, 1)
With the following Telitab set in the Data slot:
|LEASQ1|
0
2 "XC" "YC"
"1" 1 1
"2" 2 4
"3" 6 9
"4" 8 16
"5" 12 25
"6" 12 36
"7" 16 49
"8" 17 64
"9" 17 81
"10" 10 100|
This relation returns for x = 12 a value of
y=46.45
Remarks
| 0
4 "VS" "PDRA" "N" "PS"
17.0 1.0 157.5 2300
18.0 1.0 170.0 2970
19.0 1.0 184.5 3940
20.0 1.0 199.0 5140
17.0 1.1 147.0 2255
18.0 1.1 159.0 2930
19.0 1.1 173.0 3900
20.0 1.1 187.5 5110
17.0 1.2 138.5 2245
18.0 1.2 150.3 2925
19.0 1.2 163.5 3915
20.0 1.2 177.5 5150
17.0 1.3 131.5 2250
18.0 1.3 142.5 2940
19.0 1.3 155.5 3950
20.0 1.3 169.0 5200
17.0 1.4 125.5 2270
18.0 1.4 136.5 2980
19.0 1.4 148.5 3990
20.0 1.4 161.0 5260|
The interpolation of shaft power "PS" is in a sense performed in the 'inward out' direction:
first PS(and idem NS) on PDRA and then PS(and idem NS) for fixed PDRA on VS.
The expressions are the following:
PShaft = LEASQ LEASQ(1, 3, "VS", "PDRA", "PS", VShip, Pitch, 3, 2, 1)
NShaft = LEASQ(1, 3, "VS", "PDRA", "N" ,VShip, Pitch, 3, 2, 1)
in which 1 is the Telitab set number, 3 is the number of address identifiers (Ndim%), the values for "Vs" and "PDRA" are given as interpolation input and "PS"/"N" (third address identifier) are the output values of the example functions. The selected order of the approximating curve in "VS" direction is 3 and in "PDRA" direction 2 is selected. '1' is added as value for Xtrap%, so no warning is issued in the event of extrapolation. The matrix interpolation can be applied in all except Method 2, obviously since only x,y data points are provided in that case.
...
The syntax is
LEASQ(0, Npoints%, x_1, y_1, x_2, y_2,…, x_n, y_n, xint, Order%, [Xtrap%=0,1])
If Pno%=0 (the first parameter in the expression), then all x_i and y_i values should be numeric expressions. The minimum number of x,y data points in the list Npoints%, being of X,Y points of the curve, is 2. Interpolation (and extrapolation) is performed according to the curve form selected in Order%.
...
These methods are similar to syntax 1. The data used is however not presented in the dataslot of the relation, but exists in an object or a telitab.
Quick links: Function Functions overview | Attribute overview | Constants overview | Dimensions overview