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<h2><span class="refentrytitle"><a name="libgwyddion-Math.top_of_page"></a>Math</span></h2>
<p>Math — Mathematical utility functions</p>
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<div class="refsynopsisdiv">
<a name="libgwyddion-Math.synopsis"></a><h2>Synopsis</h2>
<pre class="synopsis">
#include <libgwyddion/gwyddion.h>
#define <a class="link" href="libgwyddion-Math.html#GWY-ROUND:CAPS" title="GWY_ROUND()">GWY_ROUND</a> (x)
#define <a class="link" href="libgwyddion-Math.html#GWY-SQRT3:CAPS" title="GWY_SQRT3">GWY_SQRT3</a>
#define <a class="link" href="libgwyddion-Math.html#GWY-SQRT-PI:CAPS" title="GWY_SQRT_PI">GWY_SQRT_PI</a>
#define <a class="link" href="libgwyddion-Math.html#ROUND:CAPS" title="ROUND()">ROUND</a> (x)
<a href="http://developer.gnome.org/doc/API/2.0/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> <a class="link" href="libgwyddion-Math.html#gwy-math-choleski-decompose" title="gwy_math_choleski_decompose ()">gwy_math_choleski_decompose</a> (<em class="parameter"><code><a href="http://developer.gnome.org/doc/API/2.0/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> n</code></em>,
<em class="parameter"><code><a href="http://developer.gnome.org/doc/API/2.0/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *matrix</code></em>);
<span class="returnvalue">void</span> <a class="link" href="libgwyddion-Math.html#gwy-math-choleski-solve" title="gwy_math_choleski_solve ()">gwy_math_choleski_solve</a> (<em class="parameter"><code><a href="http://developer.gnome.org/doc/API/2.0/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> n</code></em>,
<em class="parameter"><code>const <a href="http://developer.gnome.org/doc/API/2.0/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *decomp</code></em>,
<em class="parameter"><code><a href="http://developer.gnome.org/doc/API/2.0/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *rhs</code></em>);
<a href="http://developer.gnome.org/doc/API/2.0/glib/glib-Basic-Types.html#guint"><span class="returnvalue">guint</span></a> <a class="link" href="libgwyddion-Math.html#gwy-math-curvature" title="gwy_math_curvature ()">gwy_math_curvature</a> (<em class="parameter"><code>const <a href="http://developer.gnome.org/doc/API/2.0/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *coeffs</code></em>,
<em class="parameter"><code><a href="http://developer.gnome.org/doc/API/2.0/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *kappa1</code></em>,
<em class="parameter"><code><a href="http://developer.gnome.org/doc/API/2.0/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *kappa2</code></em>,
<em class="parameter"><code><a href="http://developer.gnome.org/doc/API/2.0/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *phi1</code></em>,
<em class="parameter"><code><a href="http://developer.gnome.org/doc/API/2.0/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *phi2</code></em>,
<em class="parameter"><code><a href="http://developer.gnome.org/doc/API/2.0/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *xc</code></em>,
<em class="parameter"><code><a href="http://developer.gnome.org/doc/API/2.0/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *yc</code></em>,
<em class="parameter"><code><a href="http://developer.gnome.org/doc/API/2.0/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *zc</code></em>);
<a href="http://developer.gnome.org/doc/API/2.0/glib/glib-Basic-Types.html#gint"><span class="returnvalue">gint</span></a> <a class="link" href="libgwyddion-Math.html#gwy-math-find-nearest-line" title="gwy_math_find_nearest_line ()">gwy_math_find_nearest_line</a> (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> x</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> y</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *d2min</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> n</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *coords</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *metric</code></em>);
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="returnvalue">gint</span></a> <a class="link" href="libgwyddion-Math.html#gwy-math-find-nearest-point" title="gwy_math_find_nearest_point ()">gwy_math_find_nearest_point</a> (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> x</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> y</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *d2min</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> n</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *coords</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *metric</code></em>);
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="returnvalue">gdouble</span></a> * <a class="link" href="libgwyddion-Math.html#gwy-math-fit-polynom" title="gwy_math_fit_polynom ()">gwy_math_fit_polynom</a> (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> ndata</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *xdata</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *ydata</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> n</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *coeffs</code></em>);
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="returnvalue">gdouble</span></a> <a class="link" href="libgwyddion-Math.html#gwy-math-humanize-numbers" title="gwy_math_humanize_numbers ()">gwy_math_humanize_numbers</a> (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> unit</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> maximum</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> *precision</code></em>);
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> <a class="link" href="libgwyddion-Math.html#gwy-math-is-in-polygon" title="gwy_math_is_in_polygon ()">gwy_math_is_in_polygon</a> (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> x</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> y</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *poly</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="type">guint</span></a> n</code></em>);
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="returnvalue">gdouble</span></a> * <a class="link" href="libgwyddion-Math.html#gwy-math-lin-solve" title="gwy_math_lin_solve ()">gwy_math_lin_solve</a> (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> n</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *matrix</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *rhs</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *result</code></em>);
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="returnvalue">gdouble</span></a> * <a class="link" href="libgwyddion-Math.html#gwy-math-lin-solve-rewrite" title="gwy_math_lin_solve_rewrite ()">gwy_math_lin_solve_rewrite</a> (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> n</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *matrix</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *rhs</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *result</code></em>);
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="returnvalue">gdouble</span></a> <a class="link" href="libgwyddion-Math.html#gwy-math-median" title="gwy_math_median ()">gwy_math_median</a> (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gsize"><span class="type">gsize</span></a> n</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *array</code></em>);
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="returnvalue">gdouble</span></a> <a class="link" href="libgwyddion-Math.html#gwy-math-median-uncertainty" title="gwy_math_median_uncertainty ()">gwy_math_median_uncertainty</a> (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gsize"><span class="type">gsize</span></a> n</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *array</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *uarray</code></em>);
<span class="returnvalue">void</span> <a class="link" href="libgwyddion-Math.html#gwy-math-sort" title="gwy_math_sort ()">gwy_math_sort</a> (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gsize"><span class="type">gsize</span></a> n</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *array</code></em>);
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> <a class="link" href="libgwyddion-Math.html#gwy-math-tridiag-solve-rewrite" title="gwy_math_tridiag_solve_rewrite ()">gwy_math_tridiag_solve_rewrite</a> (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> n</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *d</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *a</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *b</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *rhs</code></em>);
</pre>
</div>
<div class="refsect1">
<a name="libgwyddion-Math.description"></a><h2>Description</h2>
<p>
Functions <code class="function">gwy_math_SI_prefix()</code> and <a class="link" href="libgwyddion-Math.html#gwy-math-humanize-numbers" title="gwy_math_humanize_numbers ()"><code class="function">gwy_math_humanize_numbers()</code></a> deal with
number representation.
</p>
<p>
Nearest object finding functions <a class="link" href="libgwyddion-Math.html#gwy-math-find-nearest-line" title="gwy_math_find_nearest_line ()"><code class="function">gwy_math_find_nearest_line()</code></a> and
<a class="link" href="libgwyddion-Math.html#gwy-math-find-nearest-point" title="gwy_math_find_nearest_point ()"><code class="function">gwy_math_find_nearest_point()</code></a> can be useful in widget and vector layer
implementation.
</p>
<p>
And <a class="link" href="libgwyddion-Math.html#gwy-math-lin-solve" title="gwy_math_lin_solve ()"><code class="function">gwy_math_lin_solve()</code></a>, <a class="link" href="libgwyddion-Math.html#gwy-math-lin-solve-rewrite" title="gwy_math_lin_solve_rewrite ()"><code class="function">gwy_math_lin_solve_rewrite()</code></a>, and
<a class="link" href="libgwyddion-Math.html#gwy-math-fit-polynom" title="gwy_math_fit_polynom ()"><code class="function">gwy_math_fit_polynom()</code></a> are general purpose numeric methods.
</p>
</div>
<div class="refsect1">
<a name="libgwyddion-Math.details"></a><h2>Details</h2>
<div class="refsect2">
<a name="GWY-ROUND:CAPS"></a><h3>GWY_ROUND()</h3>
<pre class="programlisting">#define GWY_ROUND(x) ((gint)floor((x) + 0.5))
</pre>
<p>
Rounds a number to nearest integer.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td><p><span class="term"><em class="parameter"><code>x</code></em> :</span></p></td>
<td>A double value.</td>
</tr></tbody>
</table></div>
<p class="since">Since 2.5</p>
</div>
<hr>
<div class="refsect2">
<a name="GWY-SQRT3:CAPS"></a><h3>GWY_SQRT3</h3>
<pre class="programlisting">#define GWY_SQRT3 1.73205080756887729352744634150587236694280525381038
</pre>
<p>
The square root of 3.
</p>
</div>
<hr>
<div class="refsect2">
<a name="GWY-SQRT-PI:CAPS"></a><h3>GWY_SQRT_PI</h3>
<pre class="programlisting">#define GWY_SQRT_PI 1.77245385090551602729816748334114518279754945612237
</pre>
<p>
The square root of pi.
</p>
</div>
<hr>
<div class="refsect2">
<a name="ROUND:CAPS"></a><h3>ROUND()</h3>
<pre class="programlisting">#define ROUND(x) ((gint)floor((x) + 0.5))
</pre>
<div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Warning</h3>
<p><code class="literal">ROUND</code> is deprecated and should not be used in newly-written code.</p>
</div>
<p>
Rounds a number to nearest integer. Use <a class="link" href="libgwyddion-Math.html#GWY-ROUND:CAPS" title="GWY_ROUND()"><code class="literal">GWY_ROUND</code></a> instead.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td><p><span class="term"><em class="parameter"><code>x</code></em> :</span></p></td>
<td>A double value.</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gwy-math-choleski-decompose"></a><h3>gwy_math_choleski_decompose ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> gwy_math_choleski_decompose (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> n</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *matrix</code></em>);</pre>
<p>
Decomposes a symmetric positive definite matrix in place.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>n</code></em> :</span></p></td>
<td>The dimension of <em class="parameter"><code>a</code></em>.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>matrix</code></em> :</span></p></td>
<td>Lower triangular part of a symmetric matrix, stored by rows, i.e.,
matrix = [a_00 a_10 a_11 a_20 a_21 a_22 a_30 ...].</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>Whether the matrix was really positive definite. If <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#FALSE:CAPS"><code class="literal">FALSE</code></a>,
the decomposition failed and <em class="parameter"><code>a</code></em> does not contain any meaningful
values.</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gwy-math-choleski-solve"></a><h3>gwy_math_choleski_solve ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> gwy_math_choleski_solve (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> n</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *decomp</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *rhs</code></em>);</pre>
<p>
Solves a system of linear equations with predecomposed symmetric positive
definite matrix <em class="parameter"><code>a</code></em> and right hand side <em class="parameter"><code>b</code></em>.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>n</code></em> :</span></p></td>
<td>The dimension of <em class="parameter"><code>a</code></em>.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>decomp</code></em> :</span></p></td>
<td>Lower triangular part of Choleski decomposition as computed
by <a class="link" href="libgwyddion-Math.html#gwy-math-choleski-decompose" title="gwy_math_choleski_decompose ()"><code class="function">gwy_math_choleski_decompose()</code></a>.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>rhs</code></em> :</span></p></td>
<td>Right hand side vector. Is is modified in place, on return it
contains the solution.</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gwy-math-curvature"></a><h3>gwy_math_curvature ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="returnvalue">guint</span></a> gwy_math_curvature (<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *coeffs</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *kappa1</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *kappa2</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *phi1</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *phi2</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *xc</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *yc</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *zc</code></em>);</pre>
<p>
</p>
</div>
<hr>
<div class="refsect2">
<a name="gwy-math-find-nearest-line"></a><h3>gwy_math_find_nearest_line ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="returnvalue">gint</span></a> gwy_math_find_nearest_line (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> x</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> y</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *d2min</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> n</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *coords</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *metric</code></em>);</pre>
<p>
Finds the line from <em class="parameter"><code>coords</code></em> nearest to the point (<em class="parameter"><code>x</code></em>, <em class="parameter"><code>y</code></em>).
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>x</code></em> :</span></p></td>
<td>X-coordinate of the point to search.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>y</code></em> :</span></p></td>
<td>Y-coordinate of the point to search.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>d2min</code></em> :</span></p></td>
<td>Where to store the squared minimal distance, or <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>n</code></em> :</span></p></td>
<td>The number of lines (i.e. <em class="parameter"><code>coords</code></em> has 4<em class="parameter"><code>n</code></em> items).</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>coords</code></em> :</span></p></td>
<td>Line coordinates stored as x00, y00, x01, y01, x10, y10, etc.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>metric</code></em> :</span></p></td>
<td>Metric matrix (2x2, but stored sequentially by rows: m11, m12,
m21, m22), it must be positive definite. Vector norm is then
calculated as m11*x*x + (m12 + m21)*x*y + m22*y*y.
It can be <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>, standard Euclidean metric is then used.</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>The line number. It may return -1 if (<em class="parameter"><code>x</code></em>, <em class="parameter"><code>y</code></em>) doesn't lie
in the orthogonal stripe of any of the lines.</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gwy-math-find-nearest-point"></a><h3>gwy_math_find_nearest_point ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="returnvalue">gint</span></a> gwy_math_find_nearest_point (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> x</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> y</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *d2min</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> n</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *coords</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *metric</code></em>);</pre>
<p>
Finds the point from <em class="parameter"><code>coords</code></em> nearest to the point (<em class="parameter"><code>x</code></em>, <em class="parameter"><code>y</code></em>).
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>x</code></em> :</span></p></td>
<td>X-coordinate of the point to search.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>y</code></em> :</span></p></td>
<td>Y-coordinate of the point to search.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>d2min</code></em> :</span></p></td>
<td>Location to store the squared minimal distance to, or <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>n</code></em> :</span></p></td>
<td>The number of points (i.e. <em class="parameter"><code>coords</code></em> has 2<em class="parameter"><code>n</code></em> items).</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>coords</code></em> :</span></p></td>
<td>Point coordinates stored as x0, y0, x1, y1, x2, y2, etc.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>metric</code></em> :</span></p></td>
<td>Metric matrix (2x2, but stored sequentially by rows: m11, m12,
m21, m22). Vector norm is then calculated as
m11*x*x + (m12 + m21)*x*y + m22*y*y.
It can be <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>, standard Euclidean metric is then used.</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>The point number.</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gwy-math-fit-polynom"></a><h3>gwy_math_fit_polynom ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="returnvalue">gdouble</span></a> * gwy_math_fit_polynom (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> ndata</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *xdata</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *ydata</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> n</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *coeffs</code></em>);</pre>
<p>
Fits a polynom through a general (x, y) data set.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>ndata</code></em> :</span></p></td>
<td>The number of items in <em class="parameter"><code>xdata</code></em>, <em class="parameter"><code>ydata</code></em>.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>xdata</code></em> :</span></p></td>
<td>Independent variable data (of size <em class="parameter"><code>ndata</code></em>).</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>ydata</code></em> :</span></p></td>
<td>Dependent variable data (of size <em class="parameter"><code>ndata</code></em>).</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>n</code></em> :</span></p></td>
<td>The degree of polynom to fit.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>coeffs</code></em> :</span></p></td>
<td>An array of size <em class="parameter"><code>n</code></em>+1 to store the coefficients to, or <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>
(a fresh array is allocated then).</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>The coefficients of the polynom (<em class="parameter"><code>coeffs</code></em> when it was not <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>,
otherwise a newly allocated array).</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gwy-math-humanize-numbers"></a><h3>gwy_math_humanize_numbers ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="returnvalue">gdouble</span></a> gwy_math_humanize_numbers (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> unit</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> maximum</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> *precision</code></em>);</pre>
<p>
Finds a human-friendly representation for a range of numbers.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>unit</code></em> :</span></p></td>
<td>The smallest possible step.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>maximum</code></em> :</span></p></td>
<td>The maximum possible value.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>precision</code></em> :</span></p></td>
<td>A location to store <code class="function">printf()</code> precession, if not <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>.</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>The magnitude i.e., a power of 1000.</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gwy-math-is-in-polygon"></a><h3>gwy_math_is_in_polygon ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> gwy_math_is_in_polygon (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> x</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> y</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *poly</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="type">guint</span></a> n</code></em>);</pre>
<p>
Establishes wether the test point <em class="parameter"><code>x</code></em>, <em class="parameter"><code>y</code></em> is inside the polygon <em class="parameter"><code>poly</code></em>.
The polygon can be defined either clockwise or anti-clockwise and
can be a concave, convex or self-intersecting polygon.
</p>
<p>
</p>
<div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Warning</h3> Result can be either TRUE or FALSE if the test point
is *exactly* on an edge. </div>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>x</code></em> :</span></p></td>
<td>The x coordinate of the test point.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>y</code></em> :</span></p></td>
<td>The y coordinate of the test point.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>poly</code></em> :</span></p></td>
<td>An array of coordinate pairs (points) that define a
polygon.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>n</code></em> :</span></p></td>
<td>The number of corners of the polygon.</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>TRUE if the test point is inside poly and FALSE otherwise.</td>
</tr>
</tbody>
</table></div>
<p class="since">Since 2.7</p>
</div>
<hr>
<div class="refsect2">
<a name="gwy-math-lin-solve"></a><h3>gwy_math_lin_solve ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="returnvalue">gdouble</span></a> * gwy_math_lin_solve (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> n</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *matrix</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *rhs</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *result</code></em>);</pre>
<p>
Solve a regular system of linear equations.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>n</code></em> :</span></p></td>
<td>The size of the system.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>matrix</code></em> :</span></p></td>
<td>The matrix of the system (<em class="parameter"><code>n</code></em> times <em class="parameter"><code>n</code></em>), ordered by row, then
column.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>rhs</code></em> :</span></p></td>
<td>The right hand side of the sytem.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>result</code></em> :</span></p></td>
<td>Where the result should be stored. May be <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> to allocate
a fresh array for the result.</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>The solution (<em class="parameter"><code>result</code></em> if it wasn't <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>), may be <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> if the
matrix is singular.</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gwy-math-lin-solve-rewrite"></a><h3>gwy_math_lin_solve_rewrite ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="returnvalue">gdouble</span></a> * gwy_math_lin_solve_rewrite (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> n</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *matrix</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *rhs</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *result</code></em>);</pre>
<p>
Solves a regular system of linear equations.
</p>
<p>
This is a memory-conservative version of <a class="link" href="libgwyddion-Math.html#gwy-math-lin-solve" title="gwy_math_lin_solve ()"><code class="function">gwy_math_lin_solve()</code></a> overwriting
<em class="parameter"><code>matrix</code></em> and <em class="parameter"><code>rhs</code></em> with intermediate results.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>n</code></em> :</span></p></td>
<td>The size of the system.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>matrix</code></em> :</span></p></td>
<td>The matrix of the system (<em class="parameter"><code>n</code></em> times <em class="parameter"><code>n</code></em>), ordered by row, then
column.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>rhs</code></em> :</span></p></td>
<td>The right hand side of the sytem.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>result</code></em> :</span></p></td>
<td>Where the result should be stored. May be <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> to allocate
a fresh array for the result.</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>The solution (<em class="parameter"><code>result</code></em> if it wasn't <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>), may be <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> if the
matrix is singular.</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gwy-math-median"></a><h3>gwy_math_median ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="returnvalue">gdouble</span></a> gwy_math_median (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gsize"><span class="type">gsize</span></a> n</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *array</code></em>);</pre>
<p>
Finds median of an array of values using Quick select algorithm.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>n</code></em> :</span></p></td>
<td>Number of items in <em class="parameter"><code>array</code></em>.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>array</code></em> :</span></p></td>
<td>Array of doubles. It is modified by this function. All values are
kept, but their positions in the array change.</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>The median value of <em class="parameter"><code>array</code></em>.</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gwy-math-median-uncertainty"></a><h3>gwy_math_median_uncertainty ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="returnvalue">gdouble</span></a> gwy_math_median_uncertainty (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gsize"><span class="type">gsize</span></a> n</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *array</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *uarray</code></em>);</pre>
<p>
</p>
</div>
<hr>
<div class="refsect2">
<a name="gwy-math-sort"></a><h3>gwy_math_sort ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> gwy_math_sort (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gsize"><span class="type">gsize</span></a> n</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *array</code></em>);</pre>
<p>
Sorts an array of doubles using a quicksort algorithm.
</p>
<p>
This is usually about twice as fast as the generic quicksort function
thanks to specialization for doubles.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>n</code></em> :</span></p></td>
<td>Number of items in <em class="parameter"><code>array</code></em>.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>array</code></em> :</span></p></td>
<td>Array of doubles to sort in place.</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gwy-math-tridiag-solve-rewrite"></a><h3>gwy_math_tridiag_solve_rewrite ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> gwy_math_tridiag_solve_rewrite (<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> n</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *d</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *a</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *b</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gdouble"><span class="type">gdouble</span></a> *rhs</code></em>);</pre>
<p>
Solves a tridiagonal system of linear equations.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>n</code></em> :</span></p></td>
<td>The dimension of <em class="parameter"><code>d</code></em>.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>d</code></em> :</span></p></td>
<td>The diagonal of a tridiagonal matrix, its contents will be overwritten.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>a</code></em> :</span></p></td>
<td>The above-diagonal stripe (it has <em class="parameter"><code>n</code></em>-1 elements).</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>b</code></em> :</span></p></td>
<td>The below-diagonal stripe (it has <em class="parameter"><code>n</code></em>-1 elements).</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>rhs</code></em> :</span></p></td>
<td>The right hand side of the system, upon return it will contain the
solution.</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>
<a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if the elimination suceeded, <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#FALSE:CAPS"><code class="literal">FALSE</code></a> if the system is
(numerically) singular. The contents of <em class="parameter"><code>d</code></em> and <em class="parameter"><code>rhs</code></em> may be
overwritten in the case of failure too, but not to any meaningful
values.</td>
</tr>
</tbody>
</table></div>
</div>
</div>
<div class="refsect1">
<a name="libgwyddion-Math.see-also"></a><h2>See Also</h2>
<a class="link" href="libgwyddion-GwyNLFitter.html#GwyNLFitter" title="struct GwyNLFitter"><span class="type">GwyNLFitter</span></a>, non-linear least square fitter;
Math Fallback,
fallback mathematical functions
</div>
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