scilab/modules/elementary_functions/help/en_US/bitwise/bitor.xml

   1 <?xml version="1.0" encoding="UTF-8"?>
   2 <!--
   3  *
   4  * Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
   5  * Copyright (C) 2016 - Samuel GOUGEON
   6  *
   7  * Copyright (C) 2012 - 2016 - Scilab Enterprises
   8  *
   9  * This file is hereby licensed under the terms of the GNU GPL v2.0,
  10  * pursuant to article 5.3.4 of the CeCILL v.2.1.
  11  * This file was originally licensed under the terms of the CeCILL v2.1,
  12  * and continues to be available under such terms.
  13  * For more information, see the COPYING file which you should have received
  14  * along with this program.
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  16  -->
  17 <refentry xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink"
  18 xmlns:svg="http://www.w3.org/2000/svg" xmlns:ns3="http://www.w3.org/1999/xhtml"
  19 xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:db="http://docbook.org/ns/docbook"
  20 xmlns:scilab="http://www.scilab.org" xml:id="bitor" xml:lang="en">
  21     <refnamediv>
  22         <refname>bitor</refname>
  23         <refpurpose>bitwise logical OR between element-wise integers of 2 arrays</refpurpose>
  24     </refnamediv>
  25     <refsynopsisdiv>
  26         <title>Syntax</title>
  27         <synopsis>
  28             w = bitor(u, v)
  29         </synopsis>
  30     </refsynopsisdiv>
  31     <refsection>
  32         <title>Parameters</title>
  33         <variablelist>
  34             <varlistentry>
  35                 <term>u, v, w</term>
  36                 <listitem>
  37                     <para>
  38                         scalars, vectors, matrices or hypermatrices of null or
  39                         positive integers encoded as decimal or integer numbers
  40                         of any signed or unsigned <link linkend="inttype">inttype</link>.
  41                         <warning>Sparse-encoded matrices are not accepted.</warning>
  42                     </para>
  43                     <para>
  44                         If <literal>u</literal> and <literal>v</literal> have
  45                         the same type and inttype, this one is the working one.
  46                         Otherwise,
  47                         <itemizedlist>
  48                             <listitem>
  49                                 if <literal>u</literal> or <literal>v</literal>
  50                                 is decimal-encoded, the working inttype is 0
  51                                 (real decimal), even if the other operand
  52                                 is int64- or uint64-encoded.
  53                             </listitem>
  54                             <listitem>
  55                                 if <literal>u</literal> and <literal>v</literal>
  56                                 are both encoded integers, the working inttype
  57                                 is the widest of both: int8 &lt; uint8 &lt;
  58                                 int16 &lt; uint16 &lt; int32 &lt; uint32 &lt;
  59                                 int64 &lt; uint64.
  60                             </listitem>
  61                         </itemizedlist>
  62                     </para>
  63                     <para>
  64                         The result <literal>w</literal> gets the type of the
  65                         working encoding.
  66                     </para>
  67                     <para>
  68                         <literal>u</literal> and <literal>v</literal> are
  69                         processed element-wise:
  70                         <itemizedlist>
  71                             <listitem>
  72                                 If <literal>u</literal> is a single value (scalar)
  73                                 and <literal>v</literal> is a vector, matrix or
  74                                 hypermatrix, <literal>u</literal> is priorly
  75                                 expanded as <literal>u*ones(v)</literal> in order
  76                                 to operate <literal>u</literal> with every
  77                                 <literal>v</literal> component.
  78                             </listitem>
  79                             <listitem>
  80                                 Conversely, <literal>v</literal> is priorly
  81                                 expanded as <literal>v*ones(u)</literal> if it
  82                                 is a single value.
  83                             </listitem>
  84                             <listitem>
  85                                 If neither <literal>u</literal> nor <literal>v</literal>
  86                                 are scalars, they must have the same sizes.
  87                             </listitem>
  88                         </itemizedlist>
  89                     </para>
  90                     <para>
  91                         <literal>w</literal> gets the sizes of
  92                         <literal>u</literal> or/and <literal>v</literal>
  93                         arrays.
  94                     </para>
  95                 </listitem>
  96             </varlistentry>
  97         </variablelist>
  98     </refsection>
  99     <refsection>
 100         <title>Description</title>
 101         For each pair of components <literal>u(i)</literal> and <literal>v(i)</literal>,
 102         <literal>bitor(u, v)</literal> computes and returns in <literal>w(i)</literal>
 103         the bitwise OR conjunction of <literal>u(i)</literal> and <literal>v(i)</literal>
 104         bits.
 105         <note>
 106             With encoded integers, <literal>bitor(u, v)</literal> is equivalent
 107             to <literal>u | v</literal>. However, <literal>u | v</literal>
 108             demands that <literal>u</literal> and <literal>v</literal> have
 109             the same inttype, while <literal>bitor(..)</literal> accepts
 110             mixed operands.
 111         </note>
 112         <note>
 113             For any decimal integer <literal>u</literal> greater than 2^52,
 114             only its bits from log2(u) down to log2(u)-52 are encoded and can
 115             be actually taken into account. Lower bits are not stored and are
 116             then ignored.
 117         </note>
 118     </refsection>
 119     <refsection>
 120         <title>Examples</title>
 121         <programlisting role="example"><![CDATA[
 122 bitor(25, 33)
 123 dec2bin([25 33 57]')  // binary representations
 124      ]]></programlisting>
 125         <screen><![CDATA[--> bitor(25, 33)
 126  ans  =
 127    57.
 128
 129 --> dec2bin([25 33 57]'))
 130  ans  =
 131 !011001  !
 132 !100001  !
 133 !111001  !
 134 ]]></screen>
 135         <para></para>
 136         <programlisting role="example"><![CDATA[
 137 // Between 2 simple rows with zeros and ones
 138 u = [0 1 0 1];
 139 v = [0 0 1 1];
 140 bitor(u, v)  // [0 1 1 1] expected
 141
 142 // Encoded integers such as int8 are accepted:
 143 u = int8([0 1 0 1]);
 144 v = int8([0 0 1 1]);
 145 bitor(u, v)
 146
 147 // Operands of mixed types are accepted.
 148 // The type of the result is decimal if a decimal operand is involved,
 149 // or the widest integer one otherwise:
 150 u = [0 1 0 1];
 151 v = [0 0 1 1];
 152 z = bitor(u, int64(v));         type(z)       // 1 : decimal representation
 153 z = bitor(uint8(u), int8(v));   typeof(z)     // uint8
 154 z = bitor(uint8(u), int32(v));  typeof(z)     // int32
 155
 156 // Usage with 2 matrices
 157 u = [  1  2  4  8
 158       25 33 25 33 ];
 159 v = [  2  4  8 16
 160       33 25 57 57 ];
 161 bitor(u, v)      //  [ 3 6 12 24 ;  57 57 57 57 ]   expected
 162
 163 // Usage with a distributed scalar:
 164 bitor([1 2 4 8 9 10 12], 8)  // == bitor([1 2 4 8 9 10 12], [8 8 8 8 8 8 8])
 165 bitor(4, [1 2 4 8 9 10 12])  // == bitor([4 4 4 4 4 4 4], [1 2 4 8 9 10 12])
 166     ]]></programlisting>
 167         <para></para>
 168         <programlisting role="example"><![CDATA[
 169 // With encoded integers, bitor(u,v) and u|v are equivalent:
 170 u = int8([2 3 10]);
 171 v = int8(6);
 172 [bitor(u, v) ; u | v]
 173 // ... but "|" demands operands with the same type:
 174 u | 6    // mismatching int8- | decimal- encodings
 175    ]]></programlisting>
 176         <screen><![CDATA[--> u = int8([2 3 10]);
 177 --> v = int8(6);
 178 --> [bitor(u, v) ; u | v]
 179  ans  =
 180   6  7  14
 181   6  7  14
 182 --> u | 6
 183 Undefined operation for the given operands.
 184 check or define function %i_g_s for overloading.
 185 ]]></screen>
 186         <para></para>
 187         <programlisting role="example"><![CDATA[
 188 // Examples with big decimal integers:
 189
 190 u = sum(2 .^(600+[0 3 9 20 45]))        // ~ 1.46D+194
 191 v = 2^630                               // ~ 4.46D+189
 192 w = bitor(u, v)
 193 w == (u+v)  // must be true, since u is built without the bit #630
 194 bitor(u, 2^645) == u   // true, since u has already its bit #645 set to 1
 195 bitor(u, 2^601) == u   // false
 196 //
 197 n = fix(log2(u))       // Index of the heaviest bit of u
 198 bitor(u, 2^(n-52)) == u   // false: The lightest bit of u was at 0 => This changes it
 199 bitor(u, 2^(n-53)) == u   // true: Addressing bits below the lightest doesn't change u
 200    ]]></programlisting>
 201     </refsection>
 202     <refsection role="see also">
 203         <title>See also</title>
 204         <simplelist type="inline">
 205             <member>
 206                 <link linkend="or_op">|</link>
 207             </member>
 208             <member>
 209                 <link linkend="or">or</link>
 210             </member>
 211             <member>
 212                 <link linkend="bitxor">bitxor</link>
 213             </member>
 214             <member>
 215                 <link linkend="bitand">bitand</link>
 216             </member>
 217             <member>
 218                 <link linkend="dec2bin">dec2bin</link>
 219             </member>
 220         </simplelist>
 221     </refsection>
 222     <refsection role="history">
 223         <title>History</title>
 224         <revhistory>
 225             <revision>
 226                 <revnumber>6.0</revnumber>
 227                 <revdescription>
 228                     <itemizedlist>
 229                         <listitem>
 230                             Extension to positive signed encoded integers
 231                         </listitem>
 232                         <listitem>
 233                             Extension to new int64 and uint64 inttypes
 234                         </listitem>
 235                         <listitem>
 236                             Operands of mixed types or inttypes are now accepted.
 237                         </listitem>
 238                         <listitem>
 239                             bitor(scalar, array) and bitor(array, scalar) are now supported.
 240                         </listitem>
 241                         <listitem>
 242                             Extension to decimal numbers greater than
 243                             2^32 and even than 2^52,
 244                             up to 1.80D+308 (== number_properties("huge")), for
 245                             the 52 heaviest encoded bits of their unsigned mantissa.
 246                         </listitem>
 247                     </itemizedlist>
 248                 </revdescription>
 249             </revision>
 250         </revhistory>
 251     </refsection>
 252 </refentry>