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New Join Areas feature in MAPublisher 8.4

The upcoming release of MAPublisher 8.4 introduces many new features. One of the new features is called Join Areas. We have received a lot of requests from our customers to create area objects by merging common attribute values. This geoprocessing function is generally known as “dissolve”.

The picture below shows polygon objects from a USA Counties layer. The goal is to create a layer with state boundaries and summing the population count by joining the objects of the counties layer.

USA County MAP

In the MAP Attributes panel of the USA Counties layer, every object of the counties layer contains attribute information including county name, state name, FIPS codes, area in km2, population and so on. We’ll be using the StateName attribute value to combine all the county polygons into one polygon per state.

MAP Attribute of the USA County layer

This is the new Join Area dialog box. On the left side, we’ll specify 1) target layer, 2) destination (output) layer, 3) join type and 4) join method. We are trying to create state boundaries from the counties target layer so we’ll select a join type based on the StateName attribute and output it to a new layer called USA States. The join will create compound paths and since our goal is to create state polygons, we’ll dissolve borders between adjacent sub-areas.

On the right side of the dialog box are attribute value operations available for each column. These operations determine what kind of the values will result for every attribute and the operations available are different for each data type (String, Real, Integer). The screenshot below shows the attribute value operation set to Sum for Population attribute (Integer data type). When the Join Area is complete, each state polygon will have the sum of the population of all the counties that belong to it.

After running the Join Areas function, county polygons are dissolved into state boundaries.

The population values show the total sum from all the counties for every state.

This is just one example of how Join Areas can be used. It was initially a feature request and with some discussion and planning, it became real. If you have any feature requests for MAPublisher, Geographic Imager or PDF Maps, please feel free to drop us a line at support@avenza.com. We’re happy to hear from all of you!

Making dashed lines intersect at every intersection in MAPublisher

One of the great advantages of using Adobe Illustrator for a mapping project is that you can make great line styles easily. For example, to make a double line stroke and one of them is dashed:

01: Double Stroke Line

Double strokes are a line graphic style where two different line strokes overlap each other. For example, the image shows that there is a stroke with a brown color and its stroke size is 3 pts. On top of this brown line, there is a 1 pt white dash line:

02: Double stroke lines with the settings shown in the appearance panel

You might have an experience where you duplicated one line layer and assigned a different style for lines in each of those layers. However, this has some disadvantages. The file size will increase because all the line segments as well as the attribute information attached to every line object is duplicated. Also, when you apply the double stroke line to road layer, the white dash line does not intersect nicely at every intersection of the map:

02: Double stroke problem

With Adobe Illustrator CS5, these problems are solved.

0) Create a graphic style like the one shown above.

1) Open the Pathfinder panel (Window > Pathfinder).

03: Pathfinder Tool

2) Select all the line objects in the line layer.
Click the outline tool 04: Pathfinder - outline tool .

This function in the Pathfinder tool breaks lines at every intersection.

03: Pathfinder - function: breaking lines at every intersection

All the selected objects which were selected at Step 2 will be broken into segments at every intersection and they will be grouped as one object in the layer.

04: Pathfinder result - all the objects are now grouped.

3) Having the grouped objects selected, apply the graphic style with the double stoke.

4) The white dashed line is intersected at every intersection nicely.
05: dashed lines intersect at every intersection

Quick tip

When creating double stroke, make sure to select the option trick tool “Align dashes to corners & path ends, adjusting length to fit” available next to the dash line option.

Note

Since this operation involves a pathfinder functions, the attribute information will not be matintained after the “outline” function is applied to those selected line works. Our development team is looking for a possible solution to keep the attribute information for the future version of MAPublisher.