line_chart.html

<h3>NAME</h3>
line_chart(): Generate an ASCII multi-line chart based on an arbitrary query.

<h3>TYPE</h3>
Procedure

<h3>DESCRIPTION</h3>
<p>
	Given an arbitrary query, generate a poor man's ASCII multi-line chart visualizing
	query's data. Visualization includes multi-line plot, x-axis extreme values, 
	y-axis approximated values and an optional legend.
</p>
<p>
	Height of query is currently fixed, and width of query varies by amount of returned rows.
</p>


<h3>SYNOPSIS</h3>
<p>
<blockquote><pre>line_chart(
	IN values_query TEXT, 
	IN chart_legend TEXT
  )
  READS SQL DATA</pre></blockquote>
</p>
<p>
  Input:
  <ul>
    <li>
    	<strong>values_query</strong>: a query producing data to be visualized. Query columns are
    	assumed as follows:
    	<ul>
    		<li>First column makes for <i>"x"</i> values. <i>line_chart()</i> will sort the
    		results by first column ascending. The type of this column is arbitrary; it could
    		be numerical, temporal etc.</li>
    		<li>2nd [, 3rd [...]] columns are <i>"y"</i> values. You may provide up to 
    		<strong>8</strong> data columns, totaling <strong>9</strong> columns together with
    		the first <i>"x"</i> values column. Note, however, that due to low ASCII plotting
    		resolution, more columns make for less readable visualization.
    		<br/>Values of these columns are expected to be numerical.
    		</li>
    	</ul>
	</li>
    <li>
    	<strong>chart_legend</strong>: comma delimited text, listing the desired
    	legend items. There should be the same number of tokens in this parameter as there
    	are data columns in the query. However, <i>line_chart()</i> will work with less that
    	number or more; the result of a nonmatching number is a nonmatching legend.
    	<br/>You may pass <strong>NULL</strong> or <strong>''</strong> (empty text) to
    	avoid displaying a legend. 
	</li>
  </ul>
</p>

<h3>EXAMPLES</h3>
	<p>
		Show a simple sine & log computation:
	<blockquote><pre>mysql&gt; call line_chart("select n, log(n), sin(n/5)+2 from numbers where n > 0 order by n limit 80", "log n, 2 + sin n/5");
+---------+----------------------------------------------------------------------------------+
| y_scale | common_schema_chart                                                              |
+---------+----------------------------------------------------------------------------------+
| 4.38    | ---------------------------------------------------------------------########### |
| 4.11    | -----------------------------------------------------################----------- |
| 3.83    | ----------------------------------------#############--------------------------- |
| 3.56    | ------------------------------##########---------------------------------------- |
| 3.29    | -----------------------#######-------------------------------------------------- |
| 3.01    | -----*****-------######-------------*****---------------------------*****------- |
| 2.74    | ---**-----**-####-----------------**-----**-----------------------**-----**----- |
| 2.46    | -**-------##**-------------------*---------**-------------------**---------*---- |
| 2.19    | *------###----*----------------**------------*-----------------*------------**-- |
| 1.92    | -----##--------*--------------*---------------**-------------**---------------*- |
| 1.64    | ----#-----------**----------**------------------*-----------*------------------* |
| 1.37    | ---#--------------**-------*---------------------**-------**-------------------- |
| 1.10    | --#-----------------*******------------------------*******---------------------- |
| 0.82    | -#------------------------------------------------------------------------------ |
| 0.55    | -------------------------------------------------------------------------------- |
| 0.27    | -------------------------------------------------------------------------------- |
| 0.00    | #------------------------------------------------------------------------------- |
|         | v::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::v |
|         | 1                                                                             80 |
|         |     # log n                                                                      |
|         |     * 2 + sin n/5                                                                |
+---------+----------------------------------------------------------------------------------+
</pre></blockquote>
	</p>


<h3>ENVIRONMENT</h3>
MySQL 5.1 or newer

<h3>SEE ALSO</h3>
<a href="google_line_chart.html">google_line_chart()</a>

<h3>AUTHOR</h3>
Shlomi Noach