/usr/share/doc/dpuser-doc/function_transmatrix.html is in dpuser-doc 3.3+p1+dfsg-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 | <html>
<head>
<meta name="Author" content="Thomas Ott">
<title>DPUSER - The Next Generation: Function transmatrix</title>
<style type="text/css" title="currentStyle">
@import "dpuser.css";
</style>
<link rel="shortcut icon" href="dpuser.ico" type="image/xicon">
</head>
<body>
<div id="header">DPUSER - The Next Generation</div>
<div id="menu">
<ul>
<li><a href="index.html">Introduction</a></li>
<li><a href="history.html">History</a></li>
<li><a href="syntax.html">Syntax</a></li>
<li><a href="operators.html">Operators</a></li>
<li><a href="ifandloop.html">Structural commands</a></li>
<li><a href="variables.html">Data types</a></li>
<li><a href="plotting.html">Graphics</a></li>
<li><a href="fitsfiles.html">Fits files</a></li>
<li><a href="category.html">Category index</a></li>
<li><a href="functions.html">Function index</a></li>
<li><a href="procedures.html">Procedure index</a></li>
<li><a href="pgplot.html">Pgplot index</a></li>
<li><a href="examples.html">Examples</a></li>
<hr>
<li><a href="qfitsview.html">QFitsView documentation</a></li>
<hr>
</ul>
<form method="GET" action="search.html">
<input type="text" size=15 name="keywords">
<input type="submit" value="Search">
</form>
</div>
<div id="content">
<h1 class="declaration">function transmatrix</h1>
<p>
Compute the transformation matrix for two reference coordinate systems. It is described by a first order polynomial if the number of reference sources is <= 6, else a second order polynomial is used. The transformation function will be calculated using a least squares fit to given coordinates. Note that if either in REFSTARS or in IMSTARS a coordinate is exactly (-1, -1), this star will not be used to calculate the transformation matrix.
<br><br><b><font size=+2>Syntax</font></b><br>
<i>result</i> = transmatrix(REFSTARS, IMSTARS [, xerror, yerror][, /silent] [, /linear] [, /cubic] [, /rotation])
<br><br><b><font size=+2>Arguments</font></b><br>
<table CELLSPACING=0 CELLPADDING=0>
<tr VALIGN=TOP><td nowrap>REFSTARS: </td>
<td> A matrix 2xm (m >= 3) with positions of the reference stars in the reference frame (= masterlist)</td></tr>
<tr VALIGN=TOP><td nowrap>IMSTARS: </td>
<td> A matrix 2xm (same size as REFSTARS) with the positions of the same stars in the image to be transformed.</td></tr>
<tr VALIGN=TOP><td nowrap>xerror: </td>
<td> If set to a named variable, the residual error of the coordinate transform in the first axis is returned.</td></tr>
<tr VALIGN=TOP><td nowrap>yerror: </td>
<td> If set to a named variable, the residual error of the coordinate transform in the second axis is returned.</td></tr>
</table>
<br><br><b><font size=+2>Switches</font></b><br>
<table CELLSPACING=0 CELLPADDING=0>
<tr VALIGN=TOP><td nowrap>/silent: </td>
<td> Printing of output is suppressed</td></tr>
<tr VALIGN=TOP><td nowrap>/linear: </td>
<td> A 1st order polynomial is fitted (even when more than 6 reference sources are supplied)</td></tr>
<tr VALIGN=TOP><td nowrap>/cubic: </td>
<td> A 3rd order polynomial is fitted (at least 10 reference sources)</td></tr>
<tr VALIGN=TOP><td nowrap>/rotation: </td>
<td> A rotational transformation is fitted (at least 4 reference sources): x' = x0 + f*cos(a)*x - f*sin(a)*y, y' = y0 + f*sin(a)*x + f*cos(a)*y</td></tr>
</table>
<br><br><b><font size=+2>Returns</font></b><br>
For 1st and 2nd order polynomials: A matrix 2x6 which describes the coordinate transformation matrix:
<br><tt> x' = result[1,1] + result[1,2]*x + result[1,3]*y + result[1,4]*xy + result[1,5]*x^2 + result[1,6]*y^2</tt>
<br><tt> y' = result[2,1] + result[2,2]*x + result[2,3]*y + result[2,4]*xy + result[2,5]*x^2 + result[2,6]*y^2<br></tt>
For 3rd order polynomials: A matrix 2x10 which describes the coordinate transformation matrix:
<br><tt> x' = result[1,1] + result[1,2]*x + result[1,3]*y + result[1,4]*xy + result[1,5]*x^2 + result[1,6]*y^2 + result[1,7]*x^2y + result[1,8]*xy^2 + result[1,9]*x^3 + result[1,10]*y^3</tt>
<br><tt> y' = result[2,1] + result[2,2]*x + result[2,3]*y + result[2,4]*xy + result[2,5]*x^2 + result[2,6]*y^2 + result[2,7]*x^2y + result[2,8]*xy^2 + result[2,9]*x^3 + result[2,10]*y^3<br> </tt>
For rotational transformation: A matrix 1x4 which describes the coordinate transformation matrix:
<br><tt> x' = result[1] + result[3] * cos(result[4])*x - result[3] * sin(result[4])*y</tt>
<br><tt> y' = result[2] + result[3] * sin(result[4])*x + result[3] * cos(result[4])*y</tt>
<br><br><b><font size=+2>See also</font></b><br>
<a href = "function_transcoords.html">function transcoords</a><br>
<a href = "function_transform.html">function transform</a><br>
</div>
<div id="copyright">
Copyright © Thomas Ott ---- DPUSER - The Next Generation 3.3 (Rev. )
</div>
</body>
</html>
|