Tag Archives: .csv files
Features vs. feature services in ArcGIS Online
When adding features to your map from local data files, such as delimited text files (.csv and .txt) or shapefiles, the data contained in those files needs to be web-enabled before it can be used in the web map. There … Continue reading
Uploading client data to perform thematic mapping on the server
You might have read this blog post about dynamic layers in ArcGIS 10.1 for Server that describes how you can change a map service layer’s symbology on a per-request basis. In this blog post, I’ll describe a JavaScript application that takes dynamic layers to the next step and allows server-side thematic mapping using data from your local machine. Server-side rendering is useful, especially when downloading features onto a client’s browser is expensive. For example, in this particular app downloading all 3,000+ county polygons onto a client’s browser could be very slow, assuming the server is even allowed to send that many features at once.
You can try the application here:
This application allows a client to upload a CSV file onto the server and to draw counties based on an attribute from the uploaded file. As part of that process, the application executes a geoprocessing task which converts the CSV file into a table in a file geodatabase, then sets a join and a renderer to a sublayer in the dynamic map service layer. Note that every draw request that goes to the map service needs to include the full definition of the join and the renderer because requests are stateless. Continue reading
Exploring more earthquakes (let me count the ways)
This morning we awoke to the local news and reports of a big quake near Tonga, and also a couple of other sizable quakes near Sacramento. So we thought this might be a good excuse to explore several ways you can look at earthquake information using ArcGIS Explorer.
First, we went to the USGS earthquake site where we found a variety of earthquake information available in a number of different formats. As we looked at things we noticed that (as usual) there’s a lot of activity in Alaska and along the Kenai Peninsula. While we could have viewed things on the globe, we toggled ArcGIS Explorer to 2D mode then set our map projection to UTM Zone 6.
We first took a look at the KML found on the USGS site in Explorer.
We found a link to a time series KML in the popup window of the above KML, and took a look at that. Here we’ve pulled out the Explorer time slider to show the entire date range from 2007 to current.
Next we downloaded the .csv file, and added it to ArcGIS Explorer using Add Content, then choosing text files. By adding from the .csv file we could choose from a variety of attributes to display in the popup window.
Using the same text file from above we opened it in ArcCatalog as a feature class, creating a shapefile, and set the projection to WGS84 (the same as the input lat/long coordinates).
In ArcMap we used graduated symbols to show the quake events in different sizes and colors. Using the layer properties we turned off some fields and created aliases for others, then toggled on the HTML popup property. And then we exported it as a layer package which we added to ArcGIS Explorer.
And finally we connected to the GeoRSS feed to view the dynamic live feed from the USGS.
So that makes 5 ways that we used the data available from the USGS.
Weather Today, Weather Yesterday
NOAA’s National Weather Service Storm Prediction Center publishes tornado, wind, and hail reports on a daily basis, as well as offers an historical archive of past events. Under reports you can find the current storm reports, and also search back in time to retrieve previous reports. The reports are delivered as .CSV files, one of the formats that can be imported directly in ArcGIS Explorer.
Here’s yesterday’s hail reports shown in Explorer. By clicking on the report location we can view additional information, and can see there was golf ball size hail reported near El Paso, Texas, mostly pea-sized hailstones in Rosita, Colorado, and quarter-sized hail covering the ground near Elizabeth, Colorado.
And here’s what the hail report looked like a year ago yesterday. There were many more hail events reported, and the hailstorms stretched from the Oklahoma panhandle through eastern Kansas, across the southeast corner of Nebraska, and on into Iowa and parts of South Dakota and Minnesota.
To make the maps, we downloaded the .csv file with the events that we wanted from the NOAA Web site. Once we saved the .csv file locally, we used File > Import and opened the file.
Using the Import Text File Wizard, most of the defaults worked perfectly. On the first panel we just accepted all of them (after looking at Data Preview to make sure things looked ok), and clicked Next…
On the second panel most of the defaults were exactly what we wanted, but we made two additions. First, we chose the Location field from the .csv file as our Title Field. This is what we wanted to be displayed as the hover text, and is also the title of the popup window. We also chose Comments as the field from the .csv file to use in the Description. This is what we wanted shown in the popup window contents.
And here’s the final result:
See the File Import Wizard Help topic for more information on importing files.
