doc/crop.html

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   2 <html>
   3  <head>
   4   <title>Cropping Structures</title>
   5  </head>
   6  <body>
   7   <div><a href="./index.html">back to doc index</a></div>
   8   <p>Intended for use with the <a href="./concatenating.html">cat</a>
   9   function, crop can do some powerful things. Crop accepts a number and
  10   the data structure from which you want to crop.</p>
  11   <p>Start by initializing some variables.</p>
  12   <table width="100%" border="1"
  13    style="text-align: center; font-family:monospace">
  14    <tr>
  15     <td width="25%"><b>Input</b></td>
  16     <td width="15%"><b>Output</b></td>
  17     <td><b>Explanation</b></td>
  18    </tr>
  19    <tr>
  20     <td>(store "A" (vcat (cat 3 5 7) (cat 2 4 6) 2))</td>
  21     <td>[3 5 7]<br/>[2 4 6]<br/>[2 2 2]</td>
  22    </tr>
  23    <tr>
  24     <td>(store "u" (vcat 1 2 3))</td>
  25     <td>(1, 2, 3)</td>
  26    </tr>
  27    <tr>
  28     <td>(crop 2 A)</td>
  29     <td>[3 5]<br/>[2 4]<br/>[2 2]</td>
  30     <td>Get the 2 left columns <b>A</b>.</td>
  31    </tr>
  32    <tr>
  33     <td>(vcrop A 2)</td>
  34     <td>[3 5 7]<br/>[2 4 6]</td>
  35     <td>Get the bottom 2 rows of <b>A</b>.</td>
  36    </tr>
  37    <tr>
  38     <td>(crop A 1)</td>
  39     <td>(7, 6, 2)</td>
  40     <td>Only one column vector cropped from the right of <b>A</b>,
  41      it is automatically transformed into a vector.</td>
  42    </tr>
  43    <tr>
  44     <td>(vcrop 1 u)</td>
  45     <td>1</td>
  46     <td>Like the previous example, only one element is cropped from
  47      vector <b>u</b> so it is returned as a plain number.<br/>
  48      <b>NOTE:</b> To get this effect, you must use vcrop instead
  49      of crop.</td>
  50    </tr>
  51    <tr>
  52     <td>(crop 1 u)</td>
  53     <td>(1, 2, 3)</td>
  54     <td>Using crop on a vector just returns it.</td>
  55    </tr>
  56   </table>
  57  </body>
  58 </html>
  59