I have a shapefile with a road network and it seems like the roads are all listed as 1 big polyline. Is this typical is it possible to get a road network where the roads are listed individually and have names associated with them?
thanks,
Jeff
If someone sent me a shapefile of roads where all the roads were a single polyline, I would assume the person was playing a practical joke on me.
Typically, a useful shapefile of roads would at least be broken into a single line for each defined road, or even better, a network intersection-to-intersection segment shapes.
It's not a trivial task to split up a single polyline into a more useful multi-segmented shapefile.
Doing a quick Google search returns a couple of free solutions for shapefile editors although I can't vouch for any of them. I use my company's own codebase written in C# using Tatuk for working with shapefiles.
http://www.nrdb.co.uk/nrdbview/
http://www.forestpal.com/blog/?p=21
Related
I'm in the process of buying a 7.5 acre plot of land in a wooded, hilly area. I would estimate that the elevation varies about 50 feet from the bottom of the creek to the top of the hill. I would like to find a good method for measuring the topography of the land so I can create a 3D model. It would be tremendously useful to be able to try out different land development ideas and to simulate locations for future buildings.
My low-tech version of doing this would be to set up a laser level and go around taking elevation measurements in a 3' or so grid pattern. As I thought about that, I realized that smartphones and similar devices have quite a few sensors built in that might make this a lot easier.
I learned about software that will use a drone to capture data and images to automatically generate a topo map and 3D model. Drone Deploy is one such tool. I do have a DJI Phantom 4, but I don't know if it's feasible to fly such an intricate path among trees to scan the entire property. I wonder if there's another way to use this amazing modern hardware (phone or drone) to make my task easy.
I would appreciate hearing any thoughts and ideas about this!
The thing with dronedeploy is that you fly above the trees usually 30meters is ok. In a cross pattern.
Why do you want to fly between the trees? You have to explain that first.
In 2007, when I was young and foolish and before I knew about Open Street Map, I started an urban historical map project. I was working in Illustrator, it was going to be an interactive Flash piece, and my process was to draw the maps first, with the thought that I'd label some, but not all, of the street later on.
As we know Flash was began to die about 2010 and I put the project away for a number of years. I picked it up again a couple years ago and continued my earlier practice of just drawing streets and water features, this time with the intention of making it a conventional web map. Now I'm pretty close to finishing the drawing of a five-layer (1871, 1903, 1932, 1952 and 2016) historical map of a medium-sized city, though it still lacks labels.
My problem now is how to add large numbers of labels, many of them duplicates. There could be as many as 10,000 for all five layers, though as a practical matter I may have to settle for a smallish fraction of that number. Based on web searches I gather my workflow is unusual and that mine is therefore an unusual problem.
I've exported my maps and brought them into QGIS and played with the software a little. The process of adding labels to objects doesn't seem terribly efficient or user-friendly, but that's probably due to my unfamiliarity with the program.
So my question is this: Are there any tricks to speed up the painful process of adding large numbers of duplicate labels in either QGIS or ArcGIS? Since so many of the streets exist in all five layers, functionality like the ability to select multiple objects in different layers and edit their attributes simultaneously in the Attribute Table would be a godsend. (Doesn't seem possible.) So would the ability to copy the attributes from one object and paste them onto other objects. Or the ability to do either of these things in Illustrator via a plugin and then export the data along with the shapes to a GIS program.
Thanks for your help!
If I understand the issue correctly I think are several different solutions. When you say that you
Typically for a spatial layer in ArcGIS or QGIS you define how to label all features in a layer once by defining a label scheme to use across all features, 1 or 1 million. This assumes that each feature in the layer has one or more attributes in the associated table for the layer.
How are you converting the Illustrator vectors to a spatial layer? DXF?
You will likely have better/faster responses to this question by posting it to the GIS Stack exchange. https://gis.stackexchange.com/
I have been gaining interest in data visualization lately. I especially enjoy articles with narrative driven data-viz like the ones in http://polygraph.cool/ for example.
What would be a great 'hello world' project to learn about conveying information effective through data viz? I'm not sure where to start.
Thanks!
Two subreddits come to mind. Here you can find some nice applications of data visualizations, and here you can keep up to date datasets that get published. Put those two together and you can come up with some novel ideas. Looking forward to seeing your stuff in /r/dataisbeautiful!
How about starting with a data density app?
If you search on my name and "data density" you'll find some routines on the web, but that would be cheating. The way the system works is to take reciprocal of squared distance plus a fudge factor to prevent 1/d when the sample pixel point is very close to a data point. So you get the density of a 2D scatterplot.
You then need a nice visual representation of a linear scale, using colours to represent value changes. I'll give you those, I have several colour palettes at
http://www.malcolmmclean.site11.com/www/datadensity/colourschemes.c
http://www.malcolmmclean.site11.com/www/datadensity/colourschemes.h
I'm trying to create an animation of the population density of the Appalachian region from roughly 1790 to 2010 in decennial steps at the county level.
I've successfully created a choropleth for 2010 by modifying what was done in this tutorial by Nathan Yau. I've run into a few problems. For one, US county boundaries evolve rapidly over time so I can't use the same SVG file as in the tutorial. I think I need to do the following:
Obtain historical county boundaries as GIS files from here.
Convert GIS files into SVG files using Kartograph (after installing its numerous dependencies).
Obtain population data (with FIPS info) for each county in Appalachian region since 1790 from US census data.
Mimic what was done in tutorial to create choropleth for each decade and stitch together into animation.
This just seems insanely complicated for something so simple and I'm new to a lot of this so I'm not convinced I'll be able to get all of it to work. I guess my questions are the following:
Will the strategy I outlined work? Is there a better/simpler way to do what I'm trying to do?
Also, as for getting the census data, this also seems harder than it has to be. I just want a simple .csv file with say FIPS label, county name, and population for a given year, and yet the best I can find is something like this with a link to the actual source in some arcane format.
Thanks for any help!
You can download tables of population data by county from the US Census here:
http://factfinder2.census.gov/faces/tableservices/jsf/pages/productview.xhtml?src=bkmk
My name is John and I am a grad student at the University of Florida. As part of my research one of my tasks is to create a piece of software that is to display a map of the surrounding area, which shows the current location (from a GPS), and to implement a shapefile (as a boundary outline). I am not able to really get enough information to get on the right track on how to do this, and would appreciate any assistance!
The project involves a large-scale robot that will be operated by tele-communication in rough terrain. So this mapping and gps software will need to be entirely offline, but the location in use will be known. It is very preferred to find a cost effective means to doing this process (maybe even a simple API that could do the simple task, dll libraries, or active x.
My initial guess is to use a geo-referenced image (that I would get the lat and long of and know the boundaries of that image). Then from a GPS I then would treat the image as an XY plot somehow and that would provide the current position. Obviously even this step can be a challenge depending on what kind of image, map, kml file, etc that I can find and use.
So I would appreciate any advice, suggestions, or comments.
Suggest you online reference source code, and then modify their own, this project is currently on the Internet, you can through search engines to find. Good luck!