From d54fe7c1f704a63824c5bfa0ece65245572e9b27 Mon Sep 17 00:00:00 2001 From: Joseph Hunkeler Date: Wed, 4 Mar 2015 21:21:30 -0500 Subject: Initial commit --- src/slalib/sun67.htx/node159.html | 145 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 145 insertions(+) create mode 100644 src/slalib/sun67.htx/node159.html (limited to 'src/slalib/sun67.htx/node159.html') diff --git a/src/slalib/sun67.htx/node159.html b/src/slalib/sun67.htx/node159.html new file mode 100644 index 0000000..6cf76da --- /dev/null +++ b/src/slalib/sun67.htx/node159.html @@ -0,0 +1,145 @@ + + + + +SLA_PXY - Apply Linear Model + + + + + + + + + + + + +
+ +next + +up + +previous +
+ Next: SLA_RANDOM - Random Number +
+Up: SUBPROGRAM SPECIFICATIONS +
+ Previous: SLA_PVOBS - Observatory Position & Velocity +

+

+

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) +

+

+
GIVEN: +
+
+ + + + + + + + + + + + + + + + + +
NPInumber of samples
XYED(2,NP)expected $[\,x,y\,]$ for each sample
XYMD(2,NP)measured $[\,x,y\,]$ for each sample
COEFFSD(6)coefficients of model (see below)
+

+
RETURNED: +
+
+ + + + + + + + + + + + + + + + + +
XYPD(2,NP)predicted $[\,x,y\,]$ for each sample
XRMSDRMS in X
YRMSDRMS in Y
RRMSD 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: +
xp = a + bxm + cym
+ yp = d + exm + fym
+
2. +
The residuals are (xp-xe) and (yp-ye). +
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 +
+
+ +next + +up + +previous +
+ Next: SLA_RANDOM - Random Number +
+Up: SUBPROGRAM SPECIFICATIONS +
+ Previous: SLA_PVOBS - Observatory Position & Velocity +

+

+

+SLALIB --- Positional Astronomy Library
Starlink User Note 67
P. T. Wallace
12 October 1999
E-mail:ptw@star.rl.ac.uk +
+ + -- cgit