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#GEO
#FORMAT POLAR_VECTOR
# lat      lon     height     date       time   speed   direction
#DATA
 50.97     6.05      0      20030614     1200     4       90
 41.97     21.65     0      20030614     1200     5       330
 35.85     14.48     0      20030614     1200     11      170

#FORMAT NCOLS (Multi-column format)

This format allows any number of parameters to As the above file formats indicate, only one or two meteorological parameters may be stored in a geopoints file. To store more parameters in a single file, use a CSV file or something similar - see ASCII Tables. geopoints file. The #COLUMNS section is used to understand the columns, as they can be put in any order. The following column names are reserved and are treated specially: longitude, level, date, time, stnid. A column with a different name will be treated as a value column. The data should all be numeric, apart from stnid, which is stored as a string.

The start of an example file would look like the following:

#GEO
#FORMAT NCOLS
#COLUMNS
latitude longitude  time date       t2     o3    td    rh
#DATA
32.55   35.85  0600    20120218    273.9   35   280.3   75
31.72   35.98  1800    20120218    274.9   24   290.4   68
51.93   8.32   1200    20140218    278.9   28   300.5   34
41.1    20.82  1200    20150218    279.9   83   310.6   42

For Polar Vector geopoints, only the first value (speed) is considered during operations. For XY geopoints, both values are considered during most operations where it makes sense to do so. For the NCOLS format, all value columns are manipulated during operations.

Currently the level, date and time can only be used for filtering (or can be extracted into  into  Vector variables  variables for other uses). They must be present in the file but you can specify any dummy value if you do not intend to use them.

Storing and retrieving meta-data

A geopoints file can have a section of meta-data key-value pairs in its header before the #DATA section, as illustrated here:

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If geopoints variables contain meta-data and they are part of a geopointset, they can be filtered on their meta-data - see Geopointset for details.

Extracting and setting columns

There are two ways to extract columns of data from a geopoints variable.

1. Use the functions provided, e.g.

   Code Block
   language powershell
   lats = latitudes(gpt) vals = values(gpt)

   
   

2. Use column indexing, e.g.

   Code Block
   language powershell
   lats = gpt['latitude'] vals = gpt['value']

   
   

To assign values to a column, again there are 2 methods, but they have different behaviours:

1. Use the set_ functions provided - these create new geopoints variables and do not modify the originals, e.g.
   

   
   

   Code Block
   language powershell
   gpt_new = set_latitudes(gpt, lats) # lats is a vector

2. Use column indexing - this modifies the original geopoints variable and is therefore more efficient, e.g.
   

   
   

   Code Block
   language powershell
   gpt['latitude'] = lats # lats is a vector

Operations between geopoints and fieldsets

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