Pastable version of Tracking error in numbers

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            <pre class="sunburst"><span style="color:#E28964;">class</span> <span style="text-decoration:underline;">ENumber</span>
  
  <span style="color:#E28964;">attr_accessor</span> <span style="color:#3387CC;"><span style="color:#3387CC;">:</span>n</span>, <span style="color:#3387CC;"><span style="color:#3387CC;">:</span>e</span>
  
  <span style="color:#E28964;">def</span> <span style="color:#89BDFF;">initialize</span>(<span style="color:#3E87E3;"> number<span style="color:#3E87E3;">,</span> error </span>)
    <span style="color:#3E87E3;"><span style="color:#3E87E3;">@</span>n</span> <span style="color:#E28964;">=</span> number
    <span style="color:#3E87E3;"><span style="color:#3E87E3;">@</span>e</span> <span style="color:#E28964;">=</span> error
  <span style="color:#E28964;">end</span>

<span style="color:#AEAEAE;font-style:italic;">  <span style="color:#AEAEAE;font-style:italic;">#</span> Basic arithmetic. Call like (ENumber1 + ENumber2)</span>
  <span style="color:#E28964;">def</span> <span style="color:#89BDFF;">+</span>(<span style="color:#3E87E3;">o</span>); <span style="color:#3E87E3;">ENumber</span>.<span style="color:#89BDFF;">new</span>(<span style="color:#3E87E3;"><span style="color:#3E87E3;">@</span>n</span><span style="color:#E28964;">+</span>o.<span style="color:#89BDFF;">n</span>, <span style="color:#3E87E3;"><span style="color:#3E87E3;">@</span>e</span><span style="color:#E28964;">+</span>o.<span style="color:#89BDFF;">e</span>); <span style="color:#E28964;">end</span>
  <span style="color:#E28964;">def</span> <span style="color:#89BDFF;">-</span>(<span style="color:#3E87E3;">o</span>); <span style="color:#3E87E3;">ENumber</span>.<span style="color:#89BDFF;">new</span>(<span style="color:#3E87E3;"><span style="color:#3E87E3;">@</span>n</span><span style="color:#E28964;">-</span>o.<span style="color:#89BDFF;">n</span>, <span style="color:#3E87E3;"><span style="color:#3E87E3;">@</span>e</span><span style="color:#E28964;">+</span>o.<span style="color:#89BDFF;">e</span>); <span style="color:#E28964;">end</span>
  <span style="color:#E28964;">def</span> <span style="color:#89BDFF;">*</span>(<span style="color:#3E87E3;">o</span>); <span style="color:#3E87E3;">ENumber</span>.<span style="color:#89BDFF;">new</span>(<span style="color:#3E87E3;"><span style="color:#3E87E3;">@</span>n</span><span style="color:#E28964;">*</span>o.<span style="color:#89BDFF;">n</span>, <span style="color:#89BDFF;">multError</span>(o)); <span style="color:#E28964;">end</span>
  <span style="color:#E28964;">def</span> <span style="color:#89BDFF;">/</span>(<span style="color:#3E87E3;">o</span>); <span style="color:#3E87E3;">ENumber</span>.<span style="color:#89BDFF;">new</span>(<span style="color:#3E87E3;"><span style="color:#3E87E3;">@</span>n</span><span style="color:#E28964;">/</span>o.<span style="color:#89BDFF;">n</span>, <span style="color:#89BDFF;">multError</span>(o)); <span style="color:#E28964;">end</span>

<span style="color:#AEAEAE;font-style:italic;">  <span style="color:#AEAEAE;font-style:italic;">#</span> Trigonometric functions. Call like &quot;myENumber.cos&quot;</span>
  <span style="color:#E28964;">def</span> <span style="color:#89BDFF;">tan</span>; <span style="color:#89BDFF;">trig</span>(<span style="color:#3387CC;"><span style="color:#3387CC;">:</span>tan</span>); <span style="color:#E28964;">end</span>
  <span style="color:#E28964;">def</span> <span style="color:#89BDFF;">sin</span>; <span style="color:#89BDFF;">trig</span>(<span style="color:#3387CC;"><span style="color:#3387CC;">:</span>sin</span>); <span style="color:#E28964;">end</span>
  <span style="color:#E28964;">def</span> <span style="color:#89BDFF;">cos</span>; <span style="color:#89BDFF;">trig</span>(<span style="color:#3387CC;"><span style="color:#3387CC;">:</span>cos</span>); <span style="color:#E28964;">end</span>

<span style="color:#AEAEAE;font-style:italic;">  <span style="color:#AEAEAE;font-style:italic;">#</span> Print this ENumber with the number and error rounded to x and y, respectively.</span>
<span style="color:#AEAEAE;font-style:italic;">  <span style="color:#AEAEAE;font-style:italic;">#</span> Probably should find the real way to print a +/-. since it screws up when I edit</span>
<span style="color:#AEAEAE;font-style:italic;">  <span style="color:#AEAEAE;font-style:italic;">#</span> this file on a terminal without UTF-8 (ie. almost any terminal)</span>
  <span style="color:#E28964;">def</span> <span style="color:#89BDFF;">to_s</span>(<span style="color:#3E87E3;">x<span style="color:#E28964;">=</span><span style="color:#3387CC;">4</span><span style="color:#3E87E3;">,</span>y<span style="color:#E28964;">=</span>x</span>)
    <span style="color:#65B042;"><span style="color:#65B042;">&quot;</span>%.<span style="color:#DAEFA3;"><span style="color:#DAEFA3;">#{</span>x<span style="color:#DAEFA3;">}</span></span>f±%.<span style="color:#DAEFA3;"><span style="color:#DAEFA3;">#{</span>y<span style="color:#DAEFA3;">}</span></span>f<span style="color:#65B042;">&quot;</span></span> <span style="color:#E28964;">%</span> [<span style="color:#3E87E3;"><span style="color:#3E87E3;">@</span>n</span>, <span style="color:#3E87E3;"><span style="color:#3E87E3;">@</span>e</span>]
  <span style="color:#E28964;">end</span>

<span style="color:#E28964;">private</span>
  <span style="color:#E28964;">def</span> <span style="color:#89BDFF;">trig</span>(<span style="color:#3E87E3;">type</span>)
    fcn <span style="color:#E28964;">=</span> <span style="color:#9B859D;">Math</span>.<span style="color:#89BDFF;">method</span>(type)
    <span style="color:#3E87E3;">ENumber</span>.<span style="color:#89BDFF;">new</span>(fcn.<span style="color:#89BDFF;">call</span>(<span style="color:#3E87E3;"><span style="color:#3E87E3;">@</span>n</span>), <span style="color:#3387CC;">0.5</span><span style="color:#E28964;">*</span>(fcn.<span style="color:#89BDFF;">call</span>(<span style="color:#3E87E3;"><span style="color:#3E87E3;">@</span>n</span><span style="color:#E28964;">+@</span>e)<span style="color:#E28964;">-</span>fcn.<span style="color:#89BDFF;">call</span>(<span style="color:#3E87E3;"><span style="color:#3E87E3;">@</span>n</span><span style="color:#E28964;">-@</span>e)).<span style="color:#89BDFF;">abs</span> )
  <span style="color:#E28964;">end</span>

<span style="color:#E28964;">def</span> <span style="color:#89BDFF;">multError</span>(<span style="color:#3E87E3;">o</span>)
    (<span style="color:#3E87E3;"><span style="color:#3E87E3;">@</span>n</span> <span style="color:#E28964;">*</span> o.<span style="color:#89BDFF;">n</span>).<span style="color:#89BDFF;">abs</span> <span style="color:#E28964;">*</span> ((<span style="color:#3E87E3;"><span style="color:#3E87E3;">@</span>e</span> <span style="color:#E28964;">/</span> (<span style="color:#3E87E3;"><span style="color:#3E87E3;">@</span>n</span>.<span style="color:#89BDFF;">abs</span>)) <span style="color:#E28964;">+</span> (o.<span style="color:#89BDFF;">e</span> <span style="color:#E28964;">/</span> (o.<span style="color:#89BDFF;">n</span>.<span style="color:#89BDFF;">abs</span>)))
  <span style="color:#E28964;">end</span>
<span style="color:#E28964;">end</span>

<span style="color:#AEAEAE;font-style:italic;"><span style="color:#AEAEAE;font-style:italic;">#</span> Normally this file will be included as a library.</span>
<span style="color:#AEAEAE;font-style:italic;"><span style="color:#AEAEAE;font-style:italic;">#</span> If it's loaded directly, run the below. Demo/example/cheap-ass-unittest.</span>
<span style="color:#E28964;">if</span> <span style="color:#3E87E3;">__FILE__</span> <span style="color:#E28964;">==</span> <span style="color:#3E87E3;"><span style="color:#3E87E3;">$</span>0</span>
  n <span style="color:#E28964;">=</span> <span style="color:#3E87E3;">ENumber</span>.<span style="color:#89BDFF;">new</span>(<span style="color:#3387CC;">3</span>,<span style="color:#3387CC;">0.5</span>)
  m <span style="color:#E28964;">=</span> <span style="color:#3E87E3;">ENumber</span>.<span style="color:#89BDFF;">new</span>(<span style="color:#3387CC;">4</span>,<span style="color:#3387CC;">0.25</span>)
  
  puts (((m<span style="color:#E28964;">*</span>n).<span style="color:#89BDFF;">tan</span>)<span style="color:#E28964;">+</span>n).<span style="color:#89BDFF;">to_s</span>(<span style="color:#3387CC;">5</span>,<span style="color:#3387CC;">6</span>)
<span style="color:#E28964;">end</span>
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