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updates to Field calculator help from Alister Hood (fix #4405)

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alexbruy committed Feb 1, 2012
1 parent 7b2bf88 commit e23450e97c1512b790392ee7d0977848e6d4a38f
Showing with 18 additions and 14 deletions.
  1. +18 −14 resources/context_help/QgsFieldCalculator-en_US
@@ -15,26 +15,30 @@ The field calculator allows you to update fields with expressions.
</td>
<td>value of field <tt>column_name</tt></td>
</tr>
<tr><td>'string'</td><td>literal string value</td></tr>
<tr><td><i>number</i></td><td>number</td></tr>
<tr><td>'<tt>string</tt>'</td><td>literal string value</td></tr>
<tr><td><tt>number</tt></td><td>number</td></tr>
<tr><td>NULL</td><td>null value</td></tr>
<tr><td>exp(<tt>a</tt>)</td><td>Euler's number e to the power of <tt>a</tt></td></tr>
<tr><td>ln(<tt>a</tt>)</td><td>natural log (i.e. base e) of <tt>a</tt></td></tr>
<tr><td>log10(<tt>a</tt>)</td><td>log base 10 of <tt>a</tt></td></tr>
<tr><td>log(<tt>a</tt>,<tt>b</tt>)</td><td>log base <tt>b</tt> of <tt>a</tt></td></tr>
<tr><td>sqrt(<tt>a</tt>)</td><td>square root</td></tr>
<tr><td>sin(<tt>a</tt>)</td><td>sinus of <tt>a</tt></td></tr>
<tr><td>cos(<tt>a</tt>)</td><td>cosinus of <tt>b</tt></td></tr>
<tr><td>tan(<tt>a</tt>)</td><td>tangens of <tt>a</tt></td></tr>
<tr><td>asin(<tt>a</tt>)</td><td>arcussinus of <tt>a</tt></td></tr>
<tr><td>acos(<tt>a</tt>)</td><td>arcuscosinus of <tt>a</tt></td></tr>
<tr><td>atan(<tt>a</tt>)</td><td>arcustangens of <tt>a</tt></td></tr>
<tr><td>sin(<tt>a</tt>)</td><td>sine of <tt>a</tt></td></tr>
<tr><td>cos(<tt>a</tt>)</td><td>cosine of <tt>b</tt></td></tr>
<tr><td>tan(<tt>a</tt>)</td><td>tangent of <tt>a</tt></td></tr>
<tr><td>asin(<tt>a</tt>)</td><td>inverse sine of <tt>a</tt></td></tr>
<tr><td>acos(<tt>a</tt>)</td><td>inverse cosine of <tt>a</tt></td></tr>
<tr><td>atan(<tt>a</tt>)</td><td>inverse tangent of <tt>a</tt></td></tr>
<tr><td>to int(<tt>a</tt>)</td><td>convert string <tt>a</tt> to integer</td></tr>
<tr><td>to real(<tt>a</tt>)</td><td>convert string <tt>a</tt> to real</td></tr>
<tr><td>to string(<tt>a</tt>)</td><td>convert number <tt>a</tt> to string</td></tr>
<tr><td>lower(<tt>a</tt>)</td><td>convert string <tt>a</tt> to lower case</td></tr>
<tr><td>upper(<tt>a</tt>)</td><td>convert string <tt>a</tt> to upper case</td></tr>
<tr><td>length(<tt>a</tt>)</td><td>length of string <tt>a</tt></td></tr>
<tr><td>atan2(y,x)</td><td>arcustangens of y/x using the signs of the two arguments to determine the quadrant of the result.</td></tr>
<tr><td>replace(<tt>a</tt>,<i>replacethis</i>,<i>withthat</i>)</td><td>replace <i>replacethis</i> with <i>withthat</i> in string <tt>a</tt></td></td>
<tr><td>regexp_replace(<tt>a</tt>,<i>replacethis</i>,<i>withthat</i>)</td><td>replace the regular expression <i>replacethis</i> with <i>withthat</i> in string <tt>a</tt></td></td>
<tr><td>substr(<tt>a</tt>,from,len)</td><td>len characters of string <tt>a</tt> starting from from (first character index is 1)</td></td>
<tr><td>atan2(<tt>y</tt>,<tt>x</tt>)</td><td>inverse tangent of <tt>y</tt>/<tt>x</tt> using the signs of the two arguments to determine the quadrant of the result.</td></tr>
<tr><td>replace(<tt>a</tt>,<tt>replacethis</tt>,<tt>withthat</tt>)</td><td>replace <tt>replacethis</tt> with <tt>withthat</tt> in string <tt>a</tt></td></td>
<tr><td>regexp_replace(<tt>a</tt>,<tt>replacethis</tt>,<tt>withthat</tt>)</td><td>replace the regular expression <tt>replacethis</tt> with <tt>withthat</tt> in string <tt>a</tt></td></td>
<tr><td>substr(<tt>a</tt>,<tt>from</tt>,<tt>len</tt>)</td><td><tt>len</tt> characters of string <tt>a</tt> starting from <tt>from</tt> (first character index is 1)</td></td>
<tr><td><tt>a</tt> || <tt>b</tt></td><td>concatenate strings <tt>a</tt> and <tt>b</tt></td></tr>
<tr><td>$rownum</td><td>number current row</td></tr>
<tr><td>$area</td><td>area of polygon</td></tr>
@@ -43,8 +47,8 @@ The field calculator allows you to update fields with expressions.
<tr><td>$id</td><td>feature id</td></tr>
<tr><td>$x</td><td>x coordinate of point</td></tr>
<tr><td>$y</td><td>y coordinate of point</td></tr>
<tr><td>xat(n)</td><td>x coordinate of nth point of a line (indizes start at 0; negative values apply to the last index)</td></tr>
<tr><td>yat(n)</td><td>y coordinate of nth point of a line (indizes start at 0; negative values apply to the last index)</td></tr>
<tr><td>xat(<tt>n</tt>)</td><td>x coordinate of <tt>n</tt>th point of a line (indices start at 0; negative values apply to the last index)</td></tr>
<tr><td>yat(<tt>n</tt>)</td><td>y coordinate of <tt>n</tt>th point of a line (indices start at 0; negative values apply to the last index)</td></tr>
<tr><td><tt>a</tt> ^ <tt>b</tt></td><td><tt>a</tt> raised to the power of <tt>b</tt></td></tr>
<tr><td><tt>a</tt> * <tt>b</tt></td><td><tt>a</tt> multiplied by <tt>b</tt></td></tr>
<tr><td><tt>a</tt> / <tt>b</tt></td><td><tt>a</tt> divided by <tt>b</tt></td></tr>

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