scilab/modules/string/help/pt_BR/evstr.xml

   1 <?xml version="1.0" encoding="UTF-8"?>
   2 <refentry xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink"
   3     xmlns:svg="http://www.w3.org/2000/svg" xmlns:ns4="http://www.w3.org/1999/xhtml"
   4     xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:db="http://docbook.org/ns/docbook"
   5     xmlns:scilab="http://www.scilab.org" xml:id="evstr" xml:lang="pt">
   6     <refnamediv>
   7         <refname>evstr</refname>
   8         <refpurpose>avaliação de expressões</refpurpose>
   9     </refnamediv>
  10     <refsynopsisdiv>
  11         <title>Seqüência de Chamamento</title>
  12         <synopsis>
  13             H = evstr(M)
  14             H = evstr(list(M, subExpr))
  15             [H, ierr] = evstr(..)
  16         </synopsis>
  17     </refsynopsisdiv>
  18     <refsection>
  19         <title>Parâmetros</title>
  20         <variablelist>
  21           <varlistentry>
  22             <term>M</term>
  23             <listitem>
  24               <para>matriz de strings</para>
  25             </listitem>
  26           </varlistentry>
  27           <varlistentry>
  28             <term>subExpr</term>
  29             <listitem>
  30               <para>vetor de strings</para>
  31             </listitem>
  32           </varlistentry>
  33           <varlistentry>
  34             <term>H</term>
  35             <listitem>
  36               <para>matriz</para>
  37             </listitem>
  38           </varlistentry>
  39           <varlistentry>
  40             <term>ierr</term>
  41             <listitem>
  42               <para>inteiro, indicador de erro</para>
  43             </listitem>
  44           </varlistentry>
  45         </variablelist>
  46     </refsection>
  47     <refsection>
  48         <title>Descrição</title>
  49         <para>
  50             Retorna o resultado da avaliação da matriz de strings <literal>M</literal>.
  51             Cada elemento da matriz deve definir uma expressão Scilab válida.
  52         </para>
  53         <para>
  54             Se a avaliação de <literal>M</literal> levar a um erro, a versão de
  55             valor de único retorno, <literal>H=evstr(M)</literal>, levanta erro de
  56             modo usual. A versão de dois valores de retorno,
  57             <literal>[H,ierr]=evstr(M)</literal> , por outro lado, não produz erro,
  58             mas retorna o número de erro em <literal>ierr</literal>.
  59         </para>
  60         <para>
  61             Se uma lista for fornecida, <literal>subExpr</literal> é um
  62             vetor de strings, que define subexpressões que são avaliadas antes da
  63             avaliação de <literal>M</literal>. Estas subexpressões devem ser referidas
  64             como <literal>%(k)</literal> em <literal>M</literal>, onde
  65             <literal>k</literal> é o índice da subexpressão em
  66             <literal>Subexp</literal>.
  67         </para>
  68         <warning>
  69             <itemizedlist>
  70                 <listitem>
  71                     <para>
  72                     Assignments like <literal>"a = 1"</literal> are not accepted as expressions,
  73                     neither in <varname>M</varname> nor in <varname>subExpr</varname>.
  74                     <function>execstr</function> must be used instead to evaluate such expressions.
  75                     </para>
  76                 </listitem>
  77                 <listitem>
  78                     <para>
  79                     Continuation marks <literal>".."</literal> are forbidden in expressions
  80                     in <varname>M</varname> as well as in <varname>subExpr</varname>.
  81                     </para>
  82                 </listitem>
  83             </itemizedlist>
  84         </warning>
  85         <note>Special aliases:
  86             <itemizedlist>
  87                 <listitem>
  88                         <literal>"Nan"</literal> and <literal>"NaN"</literal> are parsed as
  89                         <constant>%nan</constant>.
  90                 </listitem>
  91                 <listitem>
  92                         <literal>"Inf"</literal> and <literal>"INF"</literal> are parsed as
  93                         <constant>%inf</constant>.
  94                 </listitem>
  95             </itemizedlist>
  96         </note>
  97     </refsection>
  98     <refsection>
  99         <title>Exemplos</title>
 100         <programlisting role="example"><![CDATA[
 101 a = 1; b = 2; Z = ['a','b'] ;
 102 evstr(Z)
 103
 104 a = 1; b = 2; Z = list(['%(1)','%(1)-%(2)'],['a+1','b+1']);
 105 evstr(Z)
 106
 107 evstr('NaN'), evstr('Inf')
 108
 109 //The two return values version
 110 [H, ierr] = evstr(Z) // no error
 111 Z = ['a', 'b', 'c'] ;// the variable c is undefined
 112 [H, ierr] = evstr(Z) // error 4: Undefined variable: c
 113 ]]>     </programlisting>
 114     </refsection>
 115     <refsection>
 116         <title>Ver Também</title>
 117         <simplelist type="inline">
 118             <member>
 119                 <link linkend="execstr">execstr</link>
 120             </member>
 121             <member>
 122                 <link linkend="sci2exp">sci2exp</link>
 123             </member>
 124             <member>
 125                 <link linkend="strtod">strtod</link>
 126             </member>
 127             <member>
 128                 <link linkend="brackets">concatenation</link>
 129             </member>
 130         </simplelist>
 131     </refsection>
 132     <refsection role="history">
 133         <title>Histórico</title>
 134         <revhistory>
 135             <revision>
 136                 <revnumber>5.3.0</revnumber>
 137                 <revdescription>
 138                 <literal>"Nan"</literal> and <literal>"NaN"</literal> are now parsed as <literal>%nan</literal>.
 139                 <literal>"Inf"</literal> and <literal>"INF"</literal> are now parsed as <literal>%inf</literal>.
 140                 </revdescription>
 141             </revision>
 142             <revision>
 143                 <revnumber>6.0.1</revnumber>
 144                 <revdescription>
 145                   Simple comments are now supported in almost all possible input expressions,
 146                   whatever is the shape of <literal>M</literal>.
 147                 </revdescription>
 148             </revision>
 149         </revhistory>
 150     </refsection>
 151 </refentry>