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<refentry id="vrandi">
<indexterm id="IndexVrandi"><primary>vrandi</primary></indexterm>
<refentryinfo><title>Vectorial:Random</title></refentryinfo>
<refmeta>
<refentrytitle>vrandi</refentrytitle>
</refmeta>
<refnamediv>
<refname>vrandi</refname>
<refpurpose>
Generate a sort of 'vectorial band-limited noise'
</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<para>
Generate a sort of 'vectorial band-limited noise'
</para>
</refsect1>
<refsect1>
<title>Syntax</title>
<synopsis><command>vrandi</command> ifn, krange, kcps, ielements [, idstoffset] [, iseed]
[, isize] [, ioffset]</synopsis>
</refsect1>
<refsect1>
<title>Initialization</title>
<para>
<emphasis>ifn</emphasis> - number of the table where the vectorial signal will be generated
</para>
<para>
<emphasis>ielements</emphasis> - number of elements to process
</para>
<para>
<emphasis>idstoffset</emphasis> - (optional, default=0) -- index offset for the destination table
</para>
<para>
<emphasis>iseed</emphasis> (optional, default=0.5) -- seed value for the recursive pseudo-random formula. A value between 0 and +1 will produce an initial output of <emphasis>kamp * iseed.</emphasis> A negative value will cause seed re-initialization to be skipped. A value greater than 1 will seed from system time, this is the best option to generate a different random sequence for each run.
</para>
<para>
<emphasis>isize</emphasis> (optional, default=0) -- if zero, a 16 bit number is generated. If non-zero, a 31-bit random number is generated. Default is 0.
</para>
<para>
<emphasis>ioffset</emphasis> - (optional, default=0) -- a base value added to the random result.
</para>
</refsect1>
<refsect1>
<title>Performance</title>
<para>
<emphasis>krange</emphasis> - range of random elements (from -krange to krange)
</para>
<para>
<emphasis>kcps</emphasis> - rate of generated elements in cycles per seconds
</para>
<para>
This opcode is similar to <link linkend="randi"><citetitle>randi</citetitle></link>, but operates on vectors instead of with scalar values.
</para>
<para>
Though argument <emphasis>isize</emphasis> defaults to 0, thus using a 16-bit random number generator, using the newer 31-bit algorithm is recommended, as this will produce a random sequence with a longer period (more random numbers before the sequence starts repeating).
</para>
<para>
The output is a vector contained in <emphasis>ifn</emphasis> (that must be previously allocated).
</para>
<para>
All these operators are designed to be used together with other opocdes that operate with vector such as bmscan, <link linkend="adsynt"><citetitle>adsynt</citetitle></link> etc.
</para>
<para><emphasis>Note:</emphasis> bmscan not yet available on Canonical Csound
</para>
</refsect1>
<refsect1>
<title>Examples</title>
<para>
Here is an example of the vrandi opcode. It uses the file <ulink url="examples/vrandi.csd"><citetitle>vrandi.csd</citetitle></ulink>.
<example>
<title>Example of the vrandi opcode.</title>
<para>See the sections <link linkend="UsingRealTime"><citetitle>Real-time Audio</citetitle></link> and <link linkend="CommandFlags"><citetitle>Command Line Flags</citetitle></link> for more information on using command line flags.</para>
<xi:include href="examples-xml/vrandi.csd.xml" xmlns:xi="http://www.w3.org/2001/XInclude"/>
</example>
</para>
</refsect1>
<refsect1>
<title>See also</title>
<para>
<link linkend="vrandh"><citetitle>vrandh</citetitle></link>,
<link linkend="randi"><citetitle>randi</citetitle></link>
</para>
</refsect1>
<refsect1>
<title>Credits</title>
<para>Written by Gabriel Maldonado.</para>
<para>New in Csound 5 (Previously available only on CsoundAV)</para>
</refsect1>
</refentry>
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