Subject: Marine Geospatial Ecology Tools (MGET) help
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| From: | "Jason Roberts" <> |
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| To: | "'Linda Gwen Waters'" <> |
| Cc: | <> |
| Subject: | RE: [mget-help] trouble with quivers depicting bottom currents |
| Date: | Tue, 5 Feb 2013 15:04:27 -0500 |
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Hi Linda, Nice to hear from you from this time zone! :-) I am in Washington D.C. currently... The quiver arrows are simply lines in shapefile (or geodatabase feature class, if you outputted them there). As far as I can tell, you should be able to intersect them with another GIS layer and get something. I would check the coordinate systems on both layers and make sure they both have a coordinate system defined. Then make sure they overlay visually in ArcMap. Sounds like you already did that, of course, and are wondering why the intersect does not work even though ArcMap shows a visual intersection. If you are stumped, feel free to privately send me a zip of shapefiles. I’ll see if I can determine what is happening. You should also be able to use standard ArcGIS tools to convert the vectors to points. Under Data Management toolbox à Features à Feature Vertices to Points. That will let you extract the end point of each vector. Will that work for you? Best, Jason From: Linda Gwen Waters [mailto:] Dear Jason, I'm trying to use MGET to generate a series of current vectors (at only 3 points) that are weekly averages over a 5 year time span. I managed to generate a test case of one set of quiver arrows. I wanted to use the intersect tools to find the correspondence with geographic regions (defined as polygons) where I already know species presence or absence that same week. When I try to do this, however, I get a table with no data even though I can see visually that the arrow intersects one of my polygons. Am I doing something incorrect or is what I'm trying to do not possible with MGET generated quivers? If not, does MGET have a tool to convert the u and v current vectors into a new geographic point location defining the endpoint of the vector as a lat/lon coordinate? For reference, you met me when I took your tutorial course in Portugal. I was the outside American student. Sincerely, Linda Waters North Carolina State University |