Data Format Requirements for Importing Data to GeoMapApp

Data Tables

The first row in each file must contain text column headings. The column headings can be whatever you want, but the terms 'latitude' and 'longitude' will be automatically recognised. In the Config dialog box, you will be asked to confirm the correct latitude and longitude columns by selecting the headings used in your data table. Location must be expressed in decimal degrees, with negative values for southern and western hemispheres. Do not use N,E,S,W letters. The file may include a column which specifies the comma-separated RGB color code for each data record.

Data may be imported from local files or from remote URLs. The accepted formats are:

Microsoft Excel tables:

  1. Simple embedded formulas in cells such as addition, subtraction, multiplication and division only. For spreadsheets containing more complicated formulas, we strongly recommend that you save the spreadsheet as a comma- or tab-separated text file and import that.
  2. No special formatting - it may not be properly translated.
  3. If you are assigning a color to each table entry by including a column of Red,Green,Blue values in your table, you must be sure the R,G,B column is formatted "text". If it is formatted "number" the value "255,255,255" will be interpreted as 255255255 and will not work correctly.
  4. All decimal places are shown by GeoMapApp, even if hiddden in Excel.
  5. No size limit.

Ascii (text) tables:

  1. One row per line of ascii text.
  2. Columns may be tab-, comma- or pipe-separated.
  3. Select tab-separated, comma-separated or pipe-separated from the pull-down box in the upper-right part of the "Imported Data Tables" window.

A table copied from a spreadsheet can be directly pasted into the text box window and manipulated provided it has columns of latitude and longitude.

Data can also be typed directly into the text box window. Data in the text box window can be edited.

Shapefiles

Shapefiles can be imported from your local disk or by specifying a URL. Shapefiles must be in geographic coordinates (Latitude and Longitude). Shapefile import in UTM coordinates has not yet been implemented. When importing a shapefile, select the *.shp file name but ensure that the *.dbf and *.shx components exist in the same directory. So, for example, to import a shapefile called "worlds.shp" the associated files "worlds.dbf" and "worlds.shx" must be located in the same directory as "worlds.shp".

Similarly, if importing a shape file using the URL option, only the *.shp file needs to be specified but all three files must reside at the URL.

Image Overlay Files

Images may be imported from local files. The accepted file formats are:

  1. *.jpg, *.tiff and *.png files. You will be prompted for geographic bounding coordinates.
  2. *.kmz and *.kml files, as from Google Earth. Only simple, uncomplicated files are supported.

Grid Files

Grids may be imported from local file systems (see note about disk location, below). The accepted grid file formats are:

  1. GMT3 legacy .cf (.grd) format and GMT4 default .nf (.grd) grids.
  2. ESRI ASCII (*.asc)
  3. ESRI Binary (*.hdr / *.flt)
  4. GRD98 (*.G98, Big-Endian format only)
  5. ASCII Polar (*.asc)

Choosing a Disk Location for your Grid Files

The grid import process creates a number of tiling directories and related files that are used for internal purposes. To avoid having these internal files and folders scattered about on your computer we strongly recommend that, before importing a grid, you place it a new folder. The tiling folders will be created in that same space. When importing several grids at the same time, place all of the grids in one folder. When importing individual grids one at a time, place each in its own folder otherwise the tiling directories will be overwritten each time.  

Grids - Out of Memory Problem

There may be limitations on the maximum grid size that can be imported depending upon the memory allocation of your computer. If an out-of-memory error occurs or if the import process seems to hang, it is likely that more memory has to be allocated. For that, the .jar version of GeoMapApp needs to be run from the command line. Linux/Unix installations are already .jar files. Mac and Windows users need simply go the GeoMapApp download page and select the Linux/Unix download - the GeoMapApp.jar file will be downloaded. Once the .jar file is available, open a terminal command window, as follows. For Windows 7 users, go to the Start menu, type "cmd" in the search box and select the "cmd" program from the list. For Windows XP users, go to the Start menu, select "Run" and in the Run window type "cmd". For Mac users, go to Finder > Applications > Utilities > Terminal. In the terminal command window, change directory to the location of the GeoMapApp.jar file (if it was downloaded to your Desktop, simply type "cd Desktop"). Then, type "java -jar -Xmx512m GeoMapApp.jar" and press enter. The -Xmx option specifies the maximum memory that can be used by the program being run. If that still is not enough memory, try using the -Xmx1024m option. By using this memory allocation approach, grids up to 800 MBytes in size have been successfully imported to GeoMapApp.