What format to open lat-long file

Q&A
1

Hi everyone
I have a set of files with lats & longs of objects in two columns separated by tabs. How can I import them on GPlates, and how can I apply to them my own set of euler poles to rotate them?
thanks
gio

1 Like
2

One option is to write a small program to convert the coordinates into geojson. GPlates can open geojson file.

import json
import numpy as np

lats = np.random.uniform(low=-90, high=90, size=(50,))
lons = np.random.uniform(low=-180, high=180, size=(50,))
np.savetxt('test.csv', np.c_[lons,lats],header='lon,lat',comments='', fmt='%.4f, %.4f')

data = np.genfromtxt('test.csv',skip_header=1, delimiter=',')

json_data={}
json_data['type']="FeatureCollection"
json_data["features"]=[]

for row in data:
    print(row)
    feature={}
    feature['type'] = "Feature" 
    feature["geometry"]={}
    feature["properties"]={}
    feature["geometry"]['type'] = "Point"
    feature["geometry"]['coordinates'] = [row[0], row[1]]
    json_data["features"].append(feature) 

with open('test.json', 'w') as outfile:
    json.dump(json_data, outfile)
3

To rotate them, you need rotation file.

See this link
https://docs.google.com/document/d/1nghszKv4BZpfl5vWQSBFhRfM5HrzJaj2wT1L39xXPjA/pub

4

In regards to loading the lat lon data, an alternative is to try Christian’s idea mentioned at…

https://mailman.sydney.edu.au/pipermail/gplates-discuss/2017-March/000593.html

…specifically…

probably the most simple way: Make sure you have lon lat columns only (no metadata/attibutes!) then save the file as *.gmt and load it into GPlates (suffixing .gmt will make GPlates think it is GMT’s OGR format - http://gmt.soest.hawaii.edu/doc/latest/GMT_Docs.html#the-gmt-vector-data-format-for-ogr-compatibility).

5

THANK YOU mchin very helpful!

6

THANK YOU John I’ll try out your suggestion