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    <h1 class="heading"><a href="../index.html">
        <span>Presto 321 Documentation</span></a></h1>
    <h2 class="heading"><span>7.23. Color Functions</span></h2>
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  <div class="section" id="color-functions">
<h1>7.23. Color Functions</h1>
<dl class="function">
<dt id="bar">
<code class="descname">bar</code><span class="sig-paren">(</span><em>x</em>, <em>width</em><span class="sig-paren">)</span> &#x2192; varchar</dt>
<dd><p>Renders a single bar in an ANSI bar chart using a default
<code class="docutils literal"><span class="pre">low_color</span></code> of red and a <code class="docutils literal"><span class="pre">high_color</span></code> of green.  For example,
if <code class="docutils literal"><span class="pre">x</span></code> of 25% and width of 40 are passed to this function. A
10-character red bar will be drawn followed by 30 spaces to create
a bar of 40 characters.</p>
</dd></dl>

<dl class="function">
<dt>
<code class="descname">bar</code><span class="sig-paren">(</span><em>x</em>, <em>width</em>, <em>low_color</em>, <em>high_color</em><span class="sig-paren">)</span> &#x2192; varchar</dt>
<dd><p>Renders a single line in an ANSI bar chart of the specified
<code class="docutils literal"><span class="pre">width</span></code>. The parameter <code class="docutils literal"><span class="pre">x</span></code> is a double value between [0,1].
Values of <code class="docutils literal"><span class="pre">x</span></code> that fall outside the range [0,1] will be
truncated to either a 0 or a 1 value. The <code class="docutils literal"><span class="pre">low_color</span></code> and
<code class="docutils literal"><span class="pre">high_color</span></code> capture the color to use for either end of
the horizontal bar chart.  For example, if <code class="docutils literal"><span class="pre">x</span></code> is 0.5, <code class="docutils literal"><span class="pre">width</span></code>
is 80, <code class="docutils literal"><span class="pre">low_color</span></code> is 0xFF0000, and <code class="docutils literal"><span class="pre">high_color</span></code> is 0x00FF00
this function will return a 40 character bar that varies from red
(0xFF0000) and yellow (0xFFFF00) and the remainder of the 80
character bar will be padded with spaces.</p>
<div class="figure align-center">
<img alt="../_images/functions_color_bar.png" src="../_images/functions_color_bar.png" />
</div>
</dd></dl>

<dl class="function">
<dt id="color">
<code class="descname">color</code><span class="sig-paren">(</span><em>string</em><span class="sig-paren">)</span> &#x2192; color</dt>
<dd><p>Returns a color capturing a decoded RGB value from a 4-character
string of the format “#000”.  The input string should be varchar
containing a CSS-style short rgb string or one of <code class="docutils literal"><span class="pre">black</span></code>,
<code class="docutils literal"><span class="pre">red</span></code>, <code class="docutils literal"><span class="pre">green</span></code>, <code class="docutils literal"><span class="pre">yellow</span></code>, <code class="docutils literal"><span class="pre">blue</span></code>, <code class="docutils literal"><span class="pre">magenta</span></code>, <code class="docutils literal"><span class="pre">cyan</span></code>,
<code class="docutils literal"><span class="pre">white</span></code>.</p>
</dd></dl>

<dl class="function">
<dt>
<code class="descname">color</code><span class="sig-paren">(</span><em>x</em>, <em>low</em>, <em>high</em>, <em>low_color</em>, <em>high_color</em><span class="sig-paren">)</span> &#x2192; color</dt>
<dd><p>Returns a color interpolated between <code class="docutils literal"><span class="pre">low_color</span></code> and
<code class="docutils literal"><span class="pre">high_color</span></code> using the double parameters <code class="docutils literal"><span class="pre">x</span></code>, <code class="docutils literal"><span class="pre">low</span></code>, and
<code class="docutils literal"><span class="pre">high</span></code> to calculate a fraction which is then passed to the
<code class="docutils literal"><span class="pre">color(fraction,</span> <span class="pre">low_color,</span> <span class="pre">high_color)</span></code> function shown below.
If <code class="docutils literal"><span class="pre">x</span></code> falls outside the range defined by <code class="docutils literal"><span class="pre">low</span></code> and <code class="docutils literal"><span class="pre">high</span></code>
it’s value will be truncated to fit within this range.</p>
</dd></dl>

<dl class="function">
<dt>
<code class="descname">color</code><span class="sig-paren">(</span><em>x</em>, <em>low_color</em>, <em>high_color</em><span class="sig-paren">)</span> &#x2192; color</dt>
<dd><p>Returns a color interpolated between <code class="docutils literal"><span class="pre">low_color</span></code> and
<code class="docutils literal"><span class="pre">high_color</span></code> according to the double argument <code class="docutils literal"><span class="pre">x</span></code> between 0
and 1.0.  The parameter <code class="docutils literal"><span class="pre">x</span></code> is a double value between [0,1].
Values of <code class="docutils literal"><span class="pre">x</span></code> that fall outside the range [0,1] will be
truncated to either a 0 or a 1 value.</p>
</dd></dl>

<dl class="function">
<dt id="render">
<code class="descname">render</code><span class="sig-paren">(</span><em>x</em>, <em>color</em><span class="sig-paren">)</span> &#x2192; varchar</dt>
<dd><p>Renders value <code class="docutils literal"><span class="pre">x</span></code> using the specific color using ANSI
color codes. <code class="docutils literal"><span class="pre">x</span></code> can be either a double, bigint, or varchar.</p>
</dd></dl>

<dl class="function">
<dt>
<code class="descname">render</code><span class="sig-paren">(</span><em>b</em><span class="sig-paren">)</span> &#x2192; varchar</dt>
<dd><p>Accepts boolean value <code class="docutils literal"><span class="pre">b</span></code> and renders a green true or a red
false using ANSI color codes.</p>
</dd></dl>

<dl class="function">
<dt id="rgb">
<code class="descname">rgb</code><span class="sig-paren">(</span><em>red</em>, <em>green</em>, <em>blue</em><span class="sig-paren">)</span> &#x2192; color</dt>
<dd><p>Returns a color value capturing the RGB value of three
component color values supplied as int parameters ranging from 0
to 255: <code class="docutils literal"><span class="pre">red</span></code>, <code class="docutils literal"><span class="pre">green</span></code>, <code class="docutils literal"><span class="pre">blue</span></code>.</p>
</dd></dl>

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