SLA_PXY

Apply Linear Model

ACTION:: Given arrays of expected and measured $[x, y]$ coordinates, and a linear model relating them (as produced by sla_FITXY), compute the array of predicted coordinates and the RMS residuals.
CALL:: CALL sla_PXY (NP,XYE,XYM,COEFFS,XYP,XRMS,YRMS,RRMS)

NP	I	number of samples

XYE	D(2,NP)	expected $[x, y]$ for each sample

XYM	D(2,NP)	measured $[x, y]$ for each sample

COEFFS	D(6)	coefficients of model (see below)

XYP	D(2,NP)	predicted $[x, y]$ for each sample

XRMS	D	RMS in X

YRMS	D	RMS in Y

RRMS	D	total RMS (vector sum of XRMS and YRMS)

NOTES:

(1): The model is supplied in the array COEFFS. Naming the six elements of COEFFS $a, b, c, d, e$ & $f$ , the model transforms measured coordinates $[x_{m}, y_{m}]$ into predicted coordinates $[x_{p}, y_{p}]$ as follows:

$x_{p} = a + b x_{m} + c y_{m}$
$y_{p} = d + e x_{m} + f y_{m}$
(2): The residuals are $(x_{p} - x_{e})$ and $(y_{p} - y_{e})$ .
(3): If NP is less than or equal to zero, no coordinates are transformed, and the RMS residuals are all zero.
(4): See also sla_FITXY, sla_INVF, sla_XY2XY, sla_DCMPF