The set of conventions, rules, or encoding systems that define how geographic features are represented with symbols on a map.

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32
votes
5answers
7k views

Curved point-to-point “route maps”

I have recently been looking at airlines web pages that display their routes departing a certain city to all other cities they service. I would like to be able to create similar curved routes between ...
25
votes
5answers
3k views

Coloring thousands of polygons so each is distinct from its neighbors?

I am using ArcGIS 10, and I have layers of the 2010 Census blocks, block groups, and tracts. There are thousands of polygons in these layers. I want to color them so that each is distinct from its ...
24
votes
5answers
3k views

Are there any international standards for map symbology?

We are going to let our users add points, polylines and polygons to a map. Are there any international standards for map symbology? For example for emergency symbols?
19
votes
2answers
975 views

Hand drawn sketchy symbology styles for GIS software

Often times in planning projects, a hand drawn, sketchy look is desirable in order to convey the preliminary nature of a project. Is anyone aware of any utilities/plugins for desktop GIS software (...
16
votes
3answers
5k views

Using ArcPy to get layer symbology?

Since ArcGIS 10 comes with ArcPy package, i'm wondering it is possible to use ArcPy functions to get Symbology (i.e color, width...) of a layer?
15
votes
3answers
830 views

Zigzag Line Symbol in QGIS

I'm looking for a zigzag line symbol in QGIS. Is there perhaps an easy way to do this that I'm missing? I have tried creating a marker line using a simple triangle marker (^) and adjusting the size of ...
14
votes
3answers
2k views

Best practices for visualising clustered features in web maps?

I'm looking for the best symbol to display clustered features in the ArcGIS Server JS API. I don't like the "fly-out" animated cluster symbol, as used in the Silverlight API clustering or the JS ...
14
votes
3answers
461 views

Is it possible to use symbols instead of colours to visualise raster cell values?

I have a raster image (GeoTIFF) with integer values. I know how to visualise raster values in QGIS using colormaps or similar, but I would like to assign symbols to each colour value instead - just ...
13
votes
4answers
24k views

Is there a SVG symbol library for qgis?

Im currently using default simple symbol capabilities or dingbat fonts for point objects. Is there maybe a SVG symbol library for qgis that is a bit more extensive than that which is included? I've ...
13
votes
3answers
5k views

Changing symbology at different scales in ArcMap?

I am using ArcMap 10 and I want to display my village parcel symbology differently at given scales. I have one idea to copy and paste same layer. But my question is that in a single layer, is it ...
12
votes
3answers
1k views

Crime mapping symbology

Are there any standard, publicly available symbol sets for crime mapping? What are their intended applications and their strengths and weaknesses?
12
votes
1answer
3k views

How to create desire lines in QGIS?

How can I show the flow coming from an Origin-Destination matrix as desire lines? I need a result like the one in the picture below. I need to scale them proportionally to its value (coming from a ...
11
votes
2answers
3k views

After joining shapefile with CSV file graduated symbols option unavailable in QGIS?

I have successfully joined data from a csv file to a shapefile in QGIS but for some reason I am having trouble symbolizing my data. I want to use a graduated symbology however this option is not ...
11
votes
1answer
4k views

Is there a line symbology that also shows vertices?

Is there such a thing as a line/vertices symbology? If not a workaround? In some situations, particularly when editing, I would like to see my lines as well as all the vertices similar to the effect I ...
11
votes
1answer
747 views

Is there cartographic convention to ordering legend items (high-low or low-high)?

When you symbolise a layer in ArcMap, the symbols are ordered from low value to high value by default. Is that necessarily "correct"? I've never officially studied cartography - is there a convention ...
11
votes
2answers
2k views

Is there a method to have the colour of a label automatically match the colour of the polygon indicated in the symbology tab?

My job requires that I produce several print maps every day, for a variety of different users. It is usually pretty straight-forward, but sometimes I have to make a map that uses rather confusing/...
10
votes
7answers
692 views

What is the point of standard symbology?

There are several questions on the site asking for standard symbology to represent markers of specific types of objects (i.e. Power Distribution, Crime Mapping, Emergency Symbols, Lakes). What is the ...
10
votes
4answers
7k views

How to use consistent symbology between multiple stretched rasters in ArcMap?

I have a series of continuous rasters representing the same phenomenon over time, so I need to use the same symbology across them all. So I set the stretched symbology of the first raster, with a ...
10
votes
1answer
636 views

What is the best way to represent bridges using a point vector layer in QGIS?

I'm working on a hiking/biking maps of trails in the woods which sometimes have bridges that need to be shown on the map. I'm trying to figure out the best way to capture and represent them using QGIS ...
10
votes
1answer
3k views

Permanently Change ArcMap's “Maximum Sample Size” Setting?

I've lately been working on feature classes with a huge number of polygons (e.g. all of the Census blocks within the Chicago metro area). I've been needing to symbolize them by quantities a fair ...
9
votes
2answers
1k views

How to Create Two Color Lines in QGIS?

I've been working on making mountain biking and hiking maps using Illustrator and I am now trying to move to QGIS so there's real GIS data powering the maps, making updating/scaling them easier than ...
9
votes
1answer
370 views

Adding labels with symbols to legend in ArcMap?

I'm creating a map with ArcGIS Desktop v10.2.2, showing museums as points. The museums layer has no symbol and the labels are made of a circle filled with color with the ID inside, taken from the [ID] ...
9
votes
1answer
472 views

Why is the OGC Symbology Encoding standard not being implemented and is SLD an alternative?

I searched exhaustively over the internet as well as at this How to export Symbology from ArcGIS to Microstation or QGIS? but didnt find a satisfactory answer. Hope to get the answers from the experts ...
9
votes
3answers
361 views

What does this style of line on Topographic maps indicate

If I was reading the purpose of this stackexchange site right, I could also ask general map questions. Not necessarily regarding software. Anyways, I was wondering if someone could inform me what ...
8
votes
2answers
6k views

How to change the appearance of a Feature.Vector that's already displayed?

I've created a bunch of Feature.Vectors from Point objects and assigned them a Style. Now I want to dynamically change the appearance of one of the features in real time; e.g., change it from red to ...
8
votes
4answers
4k views

Symbolising One-to-many relationships using ArcGIS Desktop?

I have a polygon feature class which has various extent areas with a name which is unique I also have a table (in a file geodatabase) that has the extent names with a score value. But there can be ...
8
votes
1answer
168 views

What is the best way to show antenna symbols on the map: point symbols or features (polygons)

I want to show a cellular network on a map. Input data is a .csv file where each string is cellular sector. The attributes are: sector id, its coordinates, its azimuth and an angle of antenna beam ...
8
votes
3answers
2k views

How to present three spatial variables in one map? [closed]

I want to assign 3 category of variables in a single map. In other words, I have to produce a cartographic visualization of the damage including a legend listing: damaged surface area in the ...
7
votes
3answers
907 views

Should I use a discrete or continuous scale for coloring a chloropleth?

I am making a choropleth for an upcoming local race using D3. There are two candidates running for an election. For any given polygon on my map, if the red candidate has more votes, the color should ...
7
votes
8answers
8k views

Manually classifying graduated data outside of range in ArcGIS for Desktop?

I have two shapefiles representing grids with values that are symbolized with graduated colors, shown below: You can see that the two shapefiles encompass similar ranges of data, but assign ...
7
votes
6answers
7k views

How do I cluster XY point data? (ArcGIS 9.3)

I have a whole bunch of icons displaying on a map, I want these clustered together as was suggested to me for a different question here... ArcGIS 9.3. How do I increase Picture Marker Symbol ...
7
votes
2answers
2k views

How to use a field-to-RGB mapping for symbology in QGIS?

Using QGIS version 1.7. I have a plain text file that lists a set of rgb values against a code. I want to use this colour table to colour a polygon layer by mapping one of its attribute fields ('...
7
votes
2answers
4k views

Modify raster layer display and symbology properties programmatically with arcpy or ArcObjects

I have over 1500 NITF files that I need to be able to modify the layer display and symbology of programmatically from within ArcMap. I need to set the properties outlined in red below: I've looked ...
7
votes
2answers
489 views

How to display nebulous boundaries between regions with indistinct edges?

I'm trying to map the boundaries between regions which don't necessarily have a hard edge. For example, areas where languages predominate don't have a distinct edge, but instead have a degree of ...
7
votes
1answer
101 views

Why are heights given at various points on roads?

In the OS 1:25000 map below I have circled some numbers next to roads. The key says "Ground survey height" and there is another entry (in brown) for "Air survey height", but since all the data in the ...
7
votes
1answer
488 views

How to migrate SVG-based styles for QGIS to other computers?

I'm working on a project that has involved creating many recolourable SVG icons and bringing them into QGIS. These are then used in layer symbologies, with these subsequent layer styles exported as ....
7
votes
3answers
3k views

Making custom, dynamically generated vector symbols in ArcGIS Desktop?

I am putting together a map of GPS-enabled vehicles, and I am hoping to display them with custom point symbols that change appearance based on a few attributes (things like velocity, heading, and a ...
6
votes
4answers
1k views

Can someone help me identify this part of the map?

I'm sure 1 is a road, but what are those bumps on the side? I'm guessing 2 is a footpath. I have no idea what 3 is, if you don't know what it is, fine, let's leave it at that. I searched for what ...
6
votes
3answers
2k views

How to normalize choropleth maps of census information?

I'm trying to improve on the census-based maps on this site, which shows census values at 5 scales from Collection Districts through to State. Currently the maps show whole numbers (eg total ...
6
votes
2answers
14k views

Using multiple attributes feature for symbology in ArcMap?

I am trying to make a map using US census data showing vacant housing to total housing on the same map. I came across the "multiple attributes" feature under the symbology tab and wondered if this ...
6
votes
2answers
905 views

How to symbolize features with NULL values in graduated symbology?

I have a polygon feature dataset, and an attribute from a different table that I join (one-to-one) within QGIS in order to symbolise the attributes as a choropleth map. However, not all polygon fields ...
6
votes
2answers
747 views

How to decide how to “stretch” raster imagery?

I have to symbolize a digital elevation model. ArcMap offers many different setting for stretching the symbology which all give widely different results. Some stretch methods symbolize the data so ...
6
votes
3answers
3k views

Is there ArcGIS Symbol Library PDF for ArcGIS Desktop i.e. index for symbols/line weights?

ESRI has an old set of PDFs from 2004 showing all the symbols available in ArcGIS at the time and their names. I don't need it often but if I'm searching for a certain symbol and don't know its name ...
6
votes
2answers
1k views

Including labels in map legend and point symbology of ArcGIS for Desktop?

I've been using gis.stackexchange for some time already and time has come for me to ask my first question here. I have point feature class with habitat types. There are two important attribute fields....
6
votes
2answers
2k views

How to display an arrow pointing to a specific bearing in QGIS

I have a number of point features which contain an attribute I call "bearing" and another one called "slope". Each point has a bearing between 0 to 359 degrees. And the slope is either "+15" or "-15", ...
6
votes
1answer
3k views

How do I make text show up on top of Markers using Carto in TileMill

I'm attempting to place intersection markers on a trail map. Each intersection has a number. I can't seem to get the text show up above the marker. If I use the opacity, I can see the text is ...
6
votes
1answer
2k views

How to create a style file for QGIS from a plain text file?

Using QGIS 1.7. I have a plain text file, which lists 115 rgb values against a map code for a geological map. Viz.: $ head gsv1Msymbology.txt MAPCODE RED GREEN BLUE Oc 143 255 255 WAT 255 255 255 ...
6
votes
2answers
937 views

Controlling “Fill Properties” in ArcGIS, so that that symbols are visible in legend?

I use marker fill symbols in my legend in ArcView 10, in order to identify different habitats, and frequently have to increase the separation of the symbols in order to make the map more readable. ...
6
votes
4answers
6k views

View vertices in ArcGIS

In ArcGIS, is it possible to change the polyline symbology to show vertices? Or do I need to extract the points via Feature Vertices To Points? This becomes a pain if I want to edit the source polygon/...
6
votes
3answers
1k views

How to place multiple symbols on one polygon centroid?

I am using QGIS for visualizing the health conditions of elderly living in an old age home, some of the elderly have multiple medical device with them and I want to show them on the map. Suppose I ...