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>From: =?gb2312?q?=D9=BE=20=C1=F5?= <address@hidden> >Organization: ? >Keywords: 200503101156.j2ABuBv2003211 IDV earthquake plot Hi- >Thanks a lot for your reply. What I really want is to >mark up the locations of earthquakes on a map(china >e.g.). > >Here is my situation: I boasted to my teacher that I >can plot earthquake location with IDV days ago, and >before long he's gonna see my result. > >I got the data from several "earthquake catalogue" on >the web, so it's just in text format like below: >7.0N 127.4E 7 >57.0N 153.0W 7.4 >13.2N 88.7W 8 >5.7S 101.1E 7.2 >23.2N 70.0E 7.8 >6.1S 102.1E 7.4 >1.9N 126.5E 7.1 >47.2N 122.5W 7 Before you can read it into the IDV, it needs to be massaged a bit. First, you need to add a header that will explain how the data should be laid out and what the names of each of the columns are. Next, you'll need (in the current IDV version) to add in a column for time. For now, this can be just a column of zeros. Lastly, you'll have to change the lat/lon values to degrees. We currently don't handle the N/S/E/W format. The result will look like (for the data above): index->(Latitude, Longitude, magnitude, Time) Latitude Longitude magnitude Time 7.0 127.4 7 0 57.0 -153.0 7.4 0 13.2 -88.7 8 0 -5.7 101.1 7.2 0 23.2 70.0 7.8 0 -6.1 102.1 7.4 0 1.9 126.5 7.1 0 47.2 -122.5 7 0 Once you have this files massaged, then use the File Chooser to load it in and set the Data Source Type to "Text Point Data files" and add the source. You should get a Field in the Data Selector that says Point Data. Display this as a plot. At first you will see nothing. You'll need to create a station model that will display your particular data. From the Edit->Resources->Station Models menu, open the Station Model Editor. Use the File->New menu to create a new station model. Call it "Earthquake" or whatever you want. From the editor, click on the Value label on the left and then click in the canvas. That will put the glyph on and pop up a window to set the properties. In the Properties window, type "magnitude" (without the quotes) in the text field and click OK. Right click on the glyph in the canvas and from the pop-up menu, select Center->Center. Now, click the File->Save menu to save this layout. Now, from your Point Data Plot Control window, select the Earthquake station model and you should see the Earthquake magnitudes plotted at their respective locations. To use the power of the 3D nature of the IDV, if you have the depth of the earthquakes, you could plot them in 3D space as well. If you modify the file to look like (substituting the appropriate values): index->(Latitude, Longitude, magnitude, Time, Altitude) Latitude Longitude magnitude Time Altitude[unit="km"] 7.0 127.4 7 0 -20 57.0 -153.0 7.4 0 -10 13.2 -88.7 8 0 -5 -5.7 101.1 7.2 0 -50 23.2 70.0 7.8 0 -45 -6.1 102.1 7.4 0 -13 1.9 126.5 7.1 0 -4 47.2 -122.5 7 0 -0 You will see the locations in 3D. You can use the View->Viewpoint->Vertical Scale.. menu to set the vertical range from -50 to 0 km. You could also modify your station model (or create a new one) that would use a shape to show the locations (e.g. a sphere). See the section of the User's Guide on using the Station Model editor. If you knew the time, you could add in real times. See this document for the format of the text files: http://www.ssec.wisc.edu/~billh/README.text on how to format the text (or other fields). Good luck. Don Murray **************************************************************************** < Unidata User Support UCAR Unidata Program < (303)497-8643 P.O. Box 3000 < address@hidden Boulder, CO 80307 < ---------------------------------------------------------------------------- < Unidata WWW Service http://my.unidata.ucar.edu/content/support < ---------------------------------------------------------------------------- < NOTE: All email exchanges with Unidata User Support are recorded in the Unidata inquiry tracking system and then made publicly available through the web. If you do not want to have your interactions made available in this way, you must let us know in each email you send to us.