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section-geocoding.html
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section-geocoding.html
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<title>mapschool: Geocoding: a free introduction to geo</title>
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<h1><a href='./'>mapschool: Geocoding</a></h1>
<p>a free introduction to geo.</p>
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<p>A great deal of geographic data is none of the above - instead of being composed of the numbers that computers understand, it is stored as text data - references to placenames, streets, addresses, and so on.</p>
<p>Unfortunately, this isn't directly mappable. Due to variance in naming and the many definitions of place, there's an indirect and often inaccurate process involved in transforming the words 'United States' into the point <code>-120, 40</code>. This process is what we call <strong>geocoding</strong>.</p>
<p>The opposite process is <strong>reverse geocoding</strong>, where the readily available data is precise geographic positions, and the objective is a human description, like <code>United States</code> or <code>1714 14th Street</code>. Likewise, this isn't always accurate - one place on earth can be inside of overlapping and conflicting boundaries or between address points.</p>
<p>Geocoding and reverse geocoding can be very tricky: coordinate position errors, poorly formatted address data, and an ever-changing grid of streets and buildings contribute to the difficulty in turning addresses into coordinates, or vice versa.</p>
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