Example: Import Shapefile and Create a Map

In this example, we show the step by step process to import a shapefile and to create a map.


To fit into this documentation, illustrations show a small Manifold desktop, with only a few panes, docked to the right side.  In real life we use a much larger Manifold desktop, and more panes would be turned on, with panes docked to the left or to the right, or undocked, as we prefer.   Right-click a pane's tab to change where it is docked.  Manifold will remember that new arrangement for our next session.





Launch Manifold and choose File - Import.  



Navigate to the folder desired and click on the .shp file desired, and press Import.   See the SHP, Shapefiles topic for more on the multi-file ensemble that comprises a "shapefile."





A new drawing called Idaho and a new table called Idaho Table are created in the Project pane.   Double-click the Idaho drawing to open it in a drawing window.





Experienced GIS uses will recognize the horizontally spread-out look of a Latitude / Longitude projection.   To see what projection is used, we can click on the Info pane.   The pane reports that GCS_World_Geodetic_1984_(WGS84) is used, which is a synonym used by some GIS packages for  Latitude / Longitude coordinate system.   The WGS84 datum is almost universally used in modern times for Latitude / Longitude projection, but some packages like to make the use of that datum part of the name.


Tech Tip:  Manifold will read whatever projection information is specified in the accessory files, such as a .prj file, that accompany the .shp shapefile to specify coordinate systems.  Depending on which program created the shapefile, different names for the same thing may be used.  For example, shapefiles in Latitude / Longitude coordinate system might state the coordinate system in use is GCS_World_Geodetic_1984_(WGS84), which is exactly the same as Latitude / Longitude using the WGS84 ellipsoid, just using a different name.    


If we like to use the same nomenclature for all of our data, we can take a moment to click the coordinate picker button in the Info pane and choose Reproject Component, and then chose Latitude / Longitude from the pop up menu.  That does not change anything in the coordinate system in use except to change the name to what is the usual terminology in Manifold.





We can do better than the default gray formatting for Idaho.   We choose View - Panes - Style to open the Style pane.





In the Style pane we click the Fill color properties button for areas.  The buttons are not captioned since everyone working with Manifold after the first few minutes knows what they are, based on the area, line and point symbols that appear.





In the pull down menu we choose a medium orange color for fill color.  The window immediately redraws using that color.

Create a Map

So far, we have displayed the imported drawing in a drawing window.  If we like, we can display it in a map.  Displaying the Idaho drawing in a map makes it more convenient to have other layers, such as background layer of Bing Streets or OpenStreetMap streets, that provide context.   There are three ways to quickly create a map in Manifold with Idaho as a layer.  Which we use depends on what projection we want to use for the map and what layers we want the map to contain.





We will use the third approach in this example.  


We click on the Project pane tab, to switch to the Project pane.





We choose File - Create - New Map.  





That launches the New Map dialog with all the drawings in the project available as layers, in this case, just the Idaho drawing.    


If we had very many drawings, images, and other possible layers in the project, we might want to limit our choices for layers (to avoid cluttering the dialog) to only the Idaho drawing.  In that case, we could have right-clicked onto the Idaho drawing and chosen Create - New Map.   That would have launched the New Map dialog with the Idaho drawing automatically picked as a layer for the map.  


The New Map dialog also allows us to create the new map named however we want, using whatever projection we want, and optionally containing a Base layer below the Idaho drawing that is any of the imageservers in our Favorite Data Sources collection.


By default, the Base layer will be the last imageserver layer we used as a base layer.  We can choose (none) from the pull-down list of imageservers in our Favorites list.  For this example we will use Bing Maps Street Map as a base layer.   This will add a layer pulled from the Bing streets web server.


The default projection used for maps is Pseudo-Mercator, or whatever other default we have specified in Tools - Options.  Pseudo-Mercator is a good choice when using imageserver base layers, since those almost always also use Pseudo-Mercator (Bing does).    We could choose a different projection using the coordinate system picker button, or we could use whatever projection the Idaho drawing uses by right-clicking on Idaho in the list pane and choosing Use Coordinate System.   We will use the default choice, Pseudo-Mercator.   See the Maps topic for details on use the other controls, if desired.





In the New Map dialog we leave the default name Map.  We check the box for Idaho to use that drawing as a layer, and we and press Create Map.


If there are other drawings in the project, those will appear as possible layers in the New Map dialog.  We can add multiple drawings to the new map as layers by checking their boxes as well, before pressing Create Map.





That creates a new Map in the project, along with a Bing Maps data source.  We double-click on the Map to open it.




The map window opens with a view that is zoomed to fit Idaho, with the background layer automatically filling in details from the Bing web server.     When maps consist of one of the standard image server layers built into Manifold, like Bing streets, plus additional layers that are drawings or images, on initial opening the map window automatically will be zoomed to fit one of the additional layers, ignoring the extent of the image server layer (which is always worldwide).


The Idaho drawing is in Latitude / Longitude, but it is automatically re-projected on the fly into Pseudo-Mercator to match the projection used by the map window.


For a more appealing display, we use the mouse wheel to zoom out one click of the mouse wheel.





We choose the Layers pane and double-click into the opacity value for the Idaho layer, to change it to 70.


The North Arrow, Scale Bar, Legend, and Grid virtual layers provide virtual overlays in map windows to show a north arrow, a scale bar, a legend, or a grid or latitude and longitude reticule over the window.  Those virtual layers are not used in this example.





The result is a partially transparent Idaho, which lets some of the Bing background layer be seen.  We have zoomed out slightly in the illustration above to show more of the surrounding map.  This is a subtle effect that provides better visual context than a completely opaque area for Idaho.   We Shift-click the Map tab to undock the map window.





We can move the undocked map window around on our Windows desktop and resize it as we like.   


Many Manifold users will work with two or three monitors so they have a large Windows desktop, and many prefer to undock their map windows and arrange them on the big desktop, so they can see multiple windows at the same time.  In the illustration above we can see how the same Idaho drawing is simultaneously seen in its own, native Latitude / Longitude projection in a drawing window even as it participates as a layer in a map window that uses Pseudo-Mercator projection, the Idaho layer being re-projected on the fly for display purposes into Pseudo-Mercator.


About that datum - A "datum" is the Earth ellipsoid used by a particular coordinate system, with the WGS84 ellipsoid being far and away the most popular in modern times, since it is the default used by most GPS systems.  Naming a coordinate system by using the name of the ellipsoid is weird, since the same ellipsoid can be used in millions of coordinate systems, like Latitude / Longitude, Lambert Conformal Conic, Mercator, and zillions of others.    So using a name like GCS_World_Geodetic_1984_(WGS84) as a synonym for Latitude / Longitude is using the name of an ellipsoid for the name of a coordinate system, when really an ellipsoid and a coordinate system are two different things.  That's OK.  When we see a coordinate system called the same name as the name of an ellipsoid, it's usually a safe bet that what they really mean is Latitude / Longitude using that specific ellipsoid.



Manifold 9 - Re-Project a Shapefile  - New coordinate system dialogs make it easier than ever to re-project data, often in only one click. This video shows how to import a shapefile and then rapidly re-project it into different coordinate systems. We then show how maps re-project their contents on the fly for display and how to exploit that to rapidly show data in different projections.


See Also





Info Pane: Component


Layers Pane


Style Pane


File - Export


Reproject Component


SHP, Shapefiles


Example: Edit a Shapefile In Place - How to edit a shapefile "in place," that is, leaving the data in the shapefile and only linking it into a project and not importing it into the project.


Example: Reproject a Drawing - An essential example on changing the projection of a drawing, either within the drawing itself, or by changing the projection of a map window that shows the drawing and on the fly reprojects the drawing for display.


Example: Import a Shapefile - ESRI shapefiles are a very popular format for publishing GIS and other spatial data.  Unfortunately, shapefiles often will not specify what projection should be used.  This example shows how to deal with that quickly and easily.