How to convert geographic data to CSV - csv

I am trying to obtain accurate site geometry for a particular location in Autodesk Revit. The site in question is located near 19621 Waters Road, Germantown MD 20874-0000. The problem is that I can only import CSV or other comma delimited text, or a CAD format, into Revit, but height data for the region at the nessisary resolution is only available from USGS mational map thingey in ArcGrid, GeoTIFF, GridFloat, and BIL_16INT formats. I am working on a computer where (because of systemadmin stuff) I can't run any unapproved executables or anything, and my home computer doesn't have Windows, only Ubuntu. Does anyone know a way to convert the data to what I need, or know of a better whay to obtain this?


If your ARC GRID is an ascii file (not binary), don't worry about .asc and just open it in Notepad.
You will find there words xllcorner, yllcorner and cellsize, and values for cell centers. Keywords xllcorner and yllcorner are coordinates of the low left corner of the grid. (And you need to know what is the coordinate system of the file and if it is the same which you want to import as csv.)
Then you can calculate (for example in Excel) the coordinates of each cell center using cellsize. And then write all this in three columns x,y,value into a text file name.csv.


I have a routine that did thins using google earth, VBA and excel... You have to install the google earth developers package but it works pretty well- grabs images off GE and coordinates it with revit VIA a CSV file.
Revit Tricks Blogspot

Related

QGIS: all my points end up in the Atlantic Ocean

I'm following the tutorial guides in QGIS webpage, but I can't correctly import the dataset from the .csv file in the guide.
Here you can download the .csv file
Here you can download the shape .shp file
I imported the shp just by double clicking on it inside of QGIS
I pressed ctrl+L to open the delimited text layer window
from there i selected the .csv file using x as longitude and y as latitude
Here the result
Wrong point localization
What I did
The latitude and longitute coordinates look correct in the .csv file
I copied a location coordinates from the world map (ireland in my case) and I created a test .csv file with those coordinates. When import the csv file in my project it is placed in the atlantic Ocean and not in Ireland.
Is this a bug? I really can't understand what is happening.
As you can see the points are relatively well distributed, that means the original information is correct but there is something that has to do with the scale of the points that does not work (even tho coordinates are not ambiguous)

You will need to know a few things.
1.If the files you are using have coordinates systems assigned to them.
I am unsure about shp files as i deal mainly in Mesh Datasets and Rasters.
I do know that the CSV coordinates or Text file coordinates if they are GPS values ie:Lat Long have to be saved into a co-ordinates system value and that the QGIS project has to use the same coordinate system. The system uses the GPS coordinates to place the points accurately on the QGIS map. My Method is to use a site like bbox and use my Coordinates system of choice and record these Lat Long values into .CSV and then copy the same CRS settings from bbox within QGIS project then the shp and or imported files end up placed correctly when you load the imported text file layer or shp file. Also file formatting is important for text files like you have ie:CSV. If you set the CRS within the QGIS project if the layer you import in is from another CRS QGIS will automatically change this to the CRS you have set. If you do not have geographic information setout correctly you will have the problem you have now also another problem is if the file does not contain CRS information at all.
But from what you are telling us this looks like a CRS mismatch problem.
2.What the coordinates system is for the files you have ie:epsg 4326 or 3857 these are two very different different systems that can drastically alter the placement of your points.
3.If they dont have a coordinate system assigned to them then you will need to assign one and use this same coordinates system within QGIS project before you import in the files. .
4.If the files do contain coordinate systems references then in QGIS you will need to set the project CRS system to the same as the files you have. This will apply the CRS to all layers you add to this project weather they are vectors, mesh, rasters and or base layers.
Good luck.

Is it possible to export geometry data from a shapefile to CSV from QGIS?

I'm trying to get geometry data from a large quantity of shapefiles into a database (Google Datastore). The thing is, I don't need to work with maps, I just need the coordinates, so I would like just the numerical coordinates. Ideally I'd like to use CSV, but any plain text would be workable. I have a Mac and have been able to get QGIS installed (I also tried udig but the interface was baffling). While it is easy to load a shp file into QGIS as a vector layer, I'm lost as to how to export the geometry, or even if it is possible.
Does anyone know how to extract plain text geometry from a shp file? Ideally with QGIS, but any method would be appreciated.

The "You can simply right-click the layer entry in QGIS and select "Save as"" approach was right
But the "GEOMETRY=AS_WKT" in the OGR layer option was missing.
I may also be a good idea to convert the coordinate system to WGS 84, as CSV are usually expected not to be projected (and shapefile sometimes are)

You can simply right-click the layer entry in QGIS and select "Save as".
In the dialog, there's an option to save as "CSV".
There are plenty of options to refine the format of the generated CSV file, as well as there are many other file formats to choose from.

Update:
See here for a solution: https://gis.stackexchange.com/a/8846
Outdated Response:
It is possible, in a sort of roundabout way...
Open the attribute table for the layer you want to save.
Select all rows.
Copy the rows
Paste into a spreadsheet
Save the spreadsheet as a csv.
Unfortunately there is no way to do this directly in QGIS.
See here for more details:
https://gis.stackexchange.com/questions/8844/get-list-of-coordinates-for-points-in-a-layer/8911#8911

I notice world file is missing the zone paramter

I'm just trying to figure out how to create world file. I saw some explanation but I notice world file having the easting and northing values but not the zone value. So how the location of the map will be identified, or I'm missing something.
Thanking you.

The world file does specify numerical geographical location for an image, but it unfortunately does not contain any information about what coordinate systems is used.
Such information typically comes in a separate file with extension .prj and is defined usually with the WKT standard and via a unique EPSG code of the coordinate system.
To simplify the search for coordinate system definitions we created an online tool:
http://epsg.io/
There you can use simple search phrases and preview position of any coordinates on a map - and also download the .prj file mentioned above.
Because you have tagged your question with "maptiler" I expect you want to cut the map tiles from your geodata and world file with the MapTiler software.
The coordinate systems can be specified directly in MapTiler easily. See http://www.maptiler.com/how-to/coordinate-systems/

extracting CSV data

I am trying to build a custom map in Tile Mill and am new to programming in general so I apologize is if comes off as uninformed. I've done research but I'm not sure if I'm looking in the right place.
My basic question: this is an embedded map of restaurants in the SF area. Is there a way for me to extract the data for the locations to use in building a custom map of my own?
http://www.sfgate.com/food/top100/2012/map/
It seems that if the location markers exist on a map, that meta data is somewhere, I just don't know how/where to access it....I believe the raw formats for inputting location into a map are CSV or KML and wondering if there is a way to extra these data types from embedded maps.
Thanks!!

View the source of the page in question, look for the data (it's under the variable mapLocs, copy it from the page, and write a little script to convert their format to CSV.
^ this is likely against at least 2 different copyrights (newspaper's & geocoder's), so proceed at your own risk.

Best way to overlay an ESRI shapefile on google maps?

What is the best way to overlay a shapefile in Google Maps?
After some reading suggests that, converting shapefile into KML and overlaying KML in Google map is an option. If that is the case, how do I convert a shapefile into KMLs?
I believe there would be a few open source tools available for this conversion. Can anyone point to a tool to covert a shapefile to KML without any loss of data?

I like using (open source and gui friendly) Quantum GIS to convert the shapefile to kml.
Google Maps API supports only a subset of the KML standard. One limitation is file size.
To reduce your file size, you can Quantum GIS's "simplify geometries" function. This "smooths" polygons.
Then you can select your layer and do a "save as kml" on it.
If you need to process a bunch of files, the process can be batched with Quantum GIS's ogr2ogr command from osgeo4w shell.
Finally, I recommend zipping your kml (with your favorite compression program) for reduced file size and saving it as kmz.

as of 12.03.2019 FusionTables is no more...
Import the Shapefile into Google FusionTables ( http://www.google.com/fusiontables ) using http://www.shpescape.com/ and from there you can use the data in a number of ways, eg. display it using GoogleMaps.

I would not use KML. Instead, use GeoJSON which you can natively consume in Google Maps API now. It is a newer feature that didn't exist from the original responses.
In any case, simply open the SHP file in Quantum GIS, and then you can output it in any format you like (KML, GeoJSON).
If you are using Google Maps for Work, I found a premium extension that handles loading shapefiles directly where you can just connect direct to the shapefile that you generate from ESRI. I did a search on the CMaps site and found this snippet which loaded US by state shapefile: https://gmapsplugin.net/cmapsanalytics/assets/shapes/usstates.shp
var cMap = new centigon.locationIntelligence.MapView();
cMap.key([your_api_key]);
cMap.layerNames(["Basic Shapes"]);
cMap.dbfKeys([['Alabama','Alaska','Arizona','Arkansas','California','Colorado','Connecticut','Delaware','District of Columbia','Florida','Georgia','Hawaii','Idaho','Illinois','Indiana','Iowa','Kansas','Kentucky','Louisiana','Maine','Maryland','Massachusetts','Michigan','Minnesota','Mississippi','Missouri','Montana','Nebraska','Nevada','New Hampshire','New Jersey','New Mexico','New York','North Carolina','North Dakota','Ohio','Oklahoma','Oregon','Pennsylvania','Rhode Island','South Carolina','South Dakota','Tennessee','Texas','Utah','Vermont','Virginia','Washington','West Virginia','Wisconsin','Wyoming']]);
cMap.userShapeKeys([['Massachusetts','Minnesota','Montana','North Dakota','Hawaii','Idaho','Washington','Arizona','California','Colorado','Nevada','New Mexico','Oregon','Utah','Wyoming','Arkansas','Iowa','Kansas','Missouri','Nebraska','Oklahoma','South Dakota','Louisiana','Texas','Connecticut','New Hampshire','Rhode Island','Vermont','Alabama','Florida','Georgia','Mississippi','South Carolina','Illinois','Indiana','Kentucky','North Carolina','Ohio','Tennessee','Virginia','Wisconsin','West Virginia','Delaware','District of Columbia','Maryland','New Jersey','New York','Pennsylvania','Maine','Michigan','Alaska']]);
cMap.labels([['Massachusetts','Minnesota','Montana','North Dakota','Hawaii','Idaho','Washington','Arizona','California','Colorado','Nevada','New Mexico','Oregon','Utah','Wyoming','Arkansas','Iowa','Kansas','Missouri','Nebraska','Oklahoma','South Dakota','Louisiana','Texas','Connecticut','New Hampshire','Rhode Island','Vermont','Alabama','Florida','Georgia','Mississippi','South Carolina','Illinois','Indiana','Kentucky','North Carolina','Ohio','Tennessee','Virginia','Wisconsin','West Virginia','Delaware','District of Columbia','Maryland','New Jersey','New York','Pennsylvania','Maine','Michigan','Alaska']]);
cMap.polyDataSources([centigon.locationIntelligence.CMapAnalytics.DATA_PROVIDERS.SHAPE_DATAPROVIDER]);
cMap.layerTypes([centigon.mapping.Layer.TYPE.POLY]);
cMap.locations([["https://gmapsplugin.net/cmapsanalytics/assets/shapes/usstates.shp"]]);
cMap.panTo("USA");
cMap.zoomLevel(3);

Do you mean shapefile as in an Esri shapefile? Either way, you should be able to perform the conversion using ogr2ogr, which is available in the GDAL packages. You need the .shp file and ideally the corresponding .dbf file (which will provide contextual information).
Also, consider using a tool like MapShaper to reduce the complexity of your shapefiles before transforming them into KML; you'll reduce filesize substantially depending on how much detail you need.

Free "Export to KML" script for ArcGIS 9
Here is a list of available methods that someone found.
Also, it seems to me that the most efficient representation of a polygon layer is by using Google Maps API's polyline encoding, which significantly compresses lat-lng data. But getting into that format takes work: use ArcMap to export Shape as lat/lng coordinates, then convert into polylines using Google Maps API.

Just to update these answers, ESRI has included this tool, known as Layer to KML in ArcMap 10.X. Also, a Map to KML tool exists.
Simply import the desired layer (vector or raster) and choose the output location, resolution, etc. Very simple tool.

2018 already... I've found this fantastic online tool http://mapshaper.org/ to convert from ESRI shapefiles to SVG, TopoJSON, GeoJSON.
Here is the explanation of how to use it https://www.statsilk.com/maps/convert-esri-shapefile-map-geojson-format
Fast and straightforward! :)