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</noscript><div id="app" class="wrapper"><header id="tableau-help-article-header" class="container--full-width quick-help-header"><div class="container--centered"><div class="header__mobile-menu quick-help-hidden"><menu-tree-toggle/></div><div class="header__logo quick-help-hidden"><a href="https://www.tableau.com/en-us/"><img src="./Resources/tableau-logo.png" class="header__logo__img" alt="Tableau"/></a></div><div class="header__search"><search-header-help placeholder="Search"/></div></div></header><div class="container--navigation-top quick-help-hidden content-only-hidden"><div id="help-subheader" class="subheader print-hidden"><div class="container--centered"><h4 class="heading--subheader">Tableau Desktop and Web Authoring Help</h4></div></div><div class="container--top-links"><div class="container--centered container--breadcrumbs"><div><breadcrumb-links-help/></div></div><div id="help-container-menu-headings" class="container--menu-headings"><nav class="nav-medium-screen"><menu-heading-links-static-help menu-title="In this article" :disabled="false" :headings="pageHeadings"/></nav></div></div></div><div class="section--main container--full-width"><div class="container--centered"><nav class="nav-side nav-side--left" role="navigation"><menu-tree-help menu-title="Contents"/></nav><article role="main"><h1 id="contentH1">Spatial Functions</h1><div class="caption article__tags content-only-hidden quick-help-hidden"><span class="article__tags--applies-to">Applies to: Tableau Cloud, Tableau Desktop, Tableau Server</span><br/><span class="article__tags--role"> </span></div><div id="content-body">&#13; <p>Spatial functions allow you to perform advanced spatial analysis and combine spatial files with data in other formats like text files or spreadsheets. For example, you might have a spatial file of city council districts, and a text file containing latitude and longitude coordinates of reported potholes. You can use a spatial calculation when creating your data source to join these files and analyze which district takes the longest to repair potholes.</p>&#13; <p>You can also create a line that connects two data points for origin-destination maps. For example, you might have a spreadsheet of public transportation data that tells you where commuters began and ended their trips. You can use a spatial calculation to see what paths commuters are taking.</p>&#13; <h2 is="heading-item" :level="2" id="spatial-functions-available-in-tableau">Spatial functions available in Tableau</h2>&#13; <td>Notes</td>&#13; <p>Supported unit names (must be in quotation marks in the calculation, such as <code>'miles'</code>):&#13; </p><ul><li><i>meters</i>: meters, metres, m</li><li><i>kilometers</i>: kilometers, kilometres, km</li><li><i>miles</i>: miles, mi</li><li><i>feet</i>: feet, ft</li></ul>&#13; <td>Definition</td>&#13; <p>For spatial points, returns a polygon shape centered over a <code>&lt;spatial point&gt;</code>, with a radius determined by the <code>&lt;distance&gt;</code> and <code>&lt;unit&gt;</code> values.</p>&#13; <p>For linestrings, computes the polygons formed by including all points within the radius distance from the linestring.</p>&#13; <td>Example</td>&#13; <td><pre xml:space="preserve">BUFFER([Spatial Point Geometry], 25, 'mi')</pre><pre xml:space="preserve">BUFFER(MAKEPOINT(47.59, -122.32), 3, 'km')</pre><pre xml:space="preserve">BUFFER(MAKELINE(MAKEPOINT(0, 20),MAKEPOINT (30, 30)),20,'km'))</pre>&#13; <td>Notes</td>&#13; <p>Supported unit names (must be in quotation marks in the calculation, such as <code>'miles'</code>):&#13; <li><i>meters</i>: meters, metres, m</li>&#13; <li><i>kilometers</i>: kilometers, kilometres, km</li>&#13; <li><i>miles</i>: miles, mi </li>&#13; <li><i>feet</i>: feet, ft</li>&#13; <td>Notes</td>&#13; <p>Supported unit names (must be in quotation marks in the calculation, such as <code>'miles'</code>):&#13; <li><i>meters</i>: meters, metres, m</li>&#13; <li><i>kilometers</i>: kilometers, kilometres, km</li>&#13; <li><i>miles</i>: miles, mi</li>&#13; <li><i>feet</i>: feet, ft</li>&#13; <td>Notes</td>&#13; <p><code>MAKEPOINT</code> can't use the automatically generated latitude and longitude fields. The data source must contain the coordinates natively. </p>&#13; <p><code>SRID</code> is a spatial reference identifier that uses <a href="https://epsg.io/" target="_blank">ESPG reference system codes<span class="sr-only">(Link opens in a new window)</span></a> to specify coordinate systems. If <code>SRID</code> is not specified, WGS84 is assumed and parameters are treated as latitude/longitude in degrees.</p>&#13; <p>You can use <code>MAKEPOINT</code> to spatially-enable a data source so that it can be joined with a spatial file using a spatial join. For more information, see <a href="maps_spatial_join.htm" class="MCXref xref" xrefformat="{paratext}">Join Spatial Files in Tableau </a>.</p>&#13; <td>Definition</td>&#13; <td>Returns the geodetic path length of the line string or strings in the <code>&lt;geometry&gt;</code> using the given <code>&lt;units&gt;</code>. </td>&#13; <td>Example</td>&#13; <td><pre xml:space="preserve">LENGTH([Spatial], 'metres')</pre>&#13; <td>Notes</td>&#13; <td>The result is <code>&lt;NaN&gt;</code> if the geometry argument has no linestrings, though other elements are permitted. </td>&#13; <h3 is="heading-item" :level="3" id="outline">OUTLINE</h3>&#13; <td>Notes</td>&#13; <p>Useful for creating a separate layer for an outline that can be styled differently than the fill.</p>&#13; <p>Supports polygons within multipolygons.</p>&#13; <td>Definition</td>&#13; <td>Returns a string describing the structure of the spatial <code>&lt;geometry&gt;</code>, such as Empty, Point, MultiPoint, LineString, MultiLinestring, Polygon, MultiPolygon, Mixed, and unsupported</td>&#13; <td>Example</td>&#13; <td><pre xml:space="preserve">SHAPETYPE(MAKEPOINT(48.5, -123.1)) = "Point"</pre>&#13; <h2 is="heading-item" :level="2" id="use-a-spatial-calculation">Use a spatial calculation</h2>&#13; <h3 is="heading-item" :level="3" id="create-a-spatial-data-source-using-makepoint"><a name="Create"/>Create a spatial data source using MAKEPOINT</h3>&#13; <p>You can use MAKEPOINT to spatially-enable a data source so that it can be joined with a spatial file using a spatial join. To use MAKEPOINT, your data must contain latitude and longitude coordinates. </p>&#13; <li value="1">Open Tableau and connect to a spatial data source. </li>&#13; <li value="2">Under Connections, click Add to add a second, non-spatial data source. <p> The two data sources are added to the canvas.</p><p class="note--tip">Tip: To get the Join dialog box to appear, double-click (control click on Mac) a data source on the canvas.</p></li>&#13; <p>Drag the non-spatial data source onto the Join dialog box.</p>&#13; <li value="4">Click the Join icon.</li>&#13; <li value="5">In the Join dialog box that appears, do the following:<ul><li>Select a join type.</li><li>Under Data Source, select a spatial field from your spatial file to join by. Spatial fields have a globe icon next to them.</li></ul></li>&#13; <li value="6">For the non-spatial data source, select Create Join Calculation as the join clause. <br/><img src="Img/maps_spatialcalcs_csvspatial.png" alt=""/><p>The calculation should look something like this:</p><p class="example"><code> MAKEPOINT(Latitude,Longitude)</code></p></li>&#13; <li value="7">Seleck <span class="uicontrol">OK.</span></li>&#13; <p>Select the Intersects join clause operator to create a data source for spatial analysis.</p>&#13; <li value="9">When finished, close the Join dialog box.</li>&#13; <p>For more information on spatial joins, see <a href="maps_spatial_join.htm" class="MCXref xref" xrefformat="{paratext}">Join Spatial Files in Tableau </a>.</p>&#13; <h3 is="heading-item" :level="3" id="create-a-visualization-using-makeline"><a name="Create2"/>Create a visualization using MAKELINE</h3>&#13; <p>In Tableau Desktop, download the Flight Path workbook from Tableau Public, <a href="https://public.tableau.com/views/UseSpatialFunctionsMakeLineExampleWorkbook/FinishedFlightpaths?:embed=y&amp;:display_count=yes&amp;publish=yes&amp;:origin=viz_share_link" target="_blank">available here<span class="sr-only">(Link opens in a new window)</span></a>. </p>&#13; <li value="1">Navigate to a new worksheet.</li>&#13; <li value="2">Select Analysis &gt; Create Calculated Field.</li>&#13; <li value="3">In the calculation that opens, do the following:</li>&#13; <li>Name the calculated field Flight Paths</li>&#13; <li>Enter the following formula</li>&#13; <p class="example"><code> MAKELINE(MAKEPOINT([Lat],[Lng]),MAKEPOINT([Dest Lat],[Dest Lng]))</code>&#13; <p>This formula takes latitude and longitude coordinates from your origin and destination cities and turns them into geographic points for spatial analysis. Those coordinates are used to build to two-point lines between origin and destination. </p>&#13; <li value="4">When finished, click <span class="uicontrol">OK</span>. </li>&#13; <p>The new calculated field appears under Dimensions in the Data pane. Just like your other fields, you can use it in one or more visualizations.</p>&#13; <li value="5">From the Data pane, double-click Flight Paths to add it to your visualization, which should automatically render as a map. </li>&#13; <p>The calculation automatically produces curved geodesic lines when the lines span longer expanses of the globe.</p>&#13; <h3 is="heading-item" :level="3" id="visualize-an-area-with-buffer">Visualize an area with BUFFER</h3>&#13; <p>In Tableau Desktop, download the Flight Path workbook from Tableau Public, <a href="https://public.tableau.com/views/UseSpatialFunctionsMakeLineExampleWorkbook/FinishedFlightpaths?:embed=y&amp;:display_count=yes&amp;publish=yes&amp;:origin=viz_share_link" target="_blank">available here<span class="sr-only">(Link opens in a new window)</span></a>. </p>&#13; <li value="1">Navigate to a new worksheet.</li>&#13; <li value="2">Right-click the Data pane and select <span class="uicontrol">Create Parameter</span>.</li>&#13; <li value="3">In the Parameter dialog that opens, set the options below:<ul><li>Name the parameter Buffer Distance</li><li>Set the Data Type to Integer</li><li>Set Allowable values to Range</li><li>Set the Minimum range to 100, the Maximum range to 1000, and the step size to 100.</li></ul><p><img src="Img/map_buffer_2.png" alt=""/></p></li>&#13; <li value="4">When finished, click <span class="uicontrol">OK.</span></li>&#13; <p>This parameter allows us to customize the radius of our buffer, ranging from 100 to 1000 miles. Right-click the parameter and select <span class="uicontrol">Show Parameter.</span></p>&#13; <li value="5">Select <span class="uicontrol">Analysis</span> &gt; <span class="uicontrol">Create Calculated Field</span>.</li>&#13; <li value="6">In the calculation that opens, do the following:</li>&#13; <li>Name the calculated field Buffer</li>&#13; <li>Enter the following formula</li>&#13; <p class="example"><code> BUFFER(MAKEPOINT([Dest Lat],[Dest Lng]),[Buffer Distance],"miles")</code>&#13; <p>The BUFFER calculation takes point spatial data and converts it into shapes with a radius in miles determined by the Buffer Distance parameter. </p>&#13; <p class="note"><span class="uicontrol">Note</span>: Because BUFFER can only be used with point spatial data, we're converting the latitude and longitude data into a point with Makepoint, as demonstrated in the previous example. &#13; <li value="7">When finished, click <span class="uicontrol">OK</span>. </li>&#13; <p>The new calculated field appears in the Data pane. Just like your other fields, you can use it in one or more visualizations.</p>&#13; <li value="8">From the Data pane, double-click <span class="uicontrol">Buffer</span> to add it to your visualization, which should automatically render as a map. </li>&#13; <li value="9">Drag <span class="uicontrol">Destination</span> to the Color panel on the Marks card to complete the visualization.</li>&#13;