how can i check if lat-lon pair repeats

i have 3 arrays lat lon and temp.It means that it is the temperature at that particular lat-lon.However i want to check if the lat-lon pair repeats anywhere and if it does only retain the first one.Code would really be appreciated!!

[Walter Roberson]

duplicates http://www.mathworks.co.uk/matlabcentral/answers/63558-is-there-any-way-to-check-if-any-point-exactly-overlaps-with-another-point