1<page xmlns="http://projectmallard.org/1.0/" 2 type="guide" 3 id="variable"> 4 5 <info> 6 <link type="guide" xref="index#equation"/> 7 </info> 8 9 <title>Variables</title> 10 11 <p> 12 To assign a value to a variable use the = symbol or choose the variable to assign to with the <gui>x</gui> button in <link xref="mouse">advanced mode</link>. 13 A variable name must only contain upper or lower characters. 14 </p> 15 <example> 16 <p> 17 x=5 18 </p> 19 <p> 20 value=82 21 </p> 22 </example> 23 <p> 24 Variables can be used in any equation and are substituted for their assigned value. 25 Variables can be inserted using the <gui>x</gui> button. 26 </p> 27 <example> 28 <p> 29 6x+3 30 </p> 31 <p> 32 xy−3x+7y−21 33 </p> 34 </example> 35 <p> 36 The following variables are always defined. 37 </p> 38 <table> 39 <tr> 40 <td><p>ans</p></td> 41 <td><p>Result of previous calculation</p></td> 42 </tr> 43 <tr> 44 <td><p>e</p></td> 45 <td><p><link xref="logarithm">Euler's Number</link></p></td> 46 </tr> 47 <tr> 48 <td><p>π</p></td> 49 <td><p><link xref="trigonometry">Pi</link></p></td> 50 </tr> 51 <tr> 52 <td><p>rand</p></td> 53 <td><p>Random value in the range [0,1] (changes on each read)</p></td> 54 </tr> 55 </table> 56</page> 57