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I have a table comprising multipoints (tracks) and points (stops between tracks). there can be several consecutive multipoints.
now, i want to merge any points lying very closely to each other (spatially and temporally) and delete all multipoints lying between them.
if there would be only one multpoint and one point in turn, i could delete the correct multipoints with comparing the respective lead point with the respective lag point (window function), but in case of group_id's 434 - 437 there are three multipoints in a row. so, how to compare the next point with the previous point in each case, even if there are more than one multipoint between those points?

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This looks like a straightforward line simplification task. Does the time stamp play any role other than determining the correct sequence of points? – whuber Jun 12 '13 at 13:55
yes, it does, like some other attributes i left out here. i definitely need all informations from the points surrounding the deleted multipoints... – Berlin_J Jun 13 '13 at 7:22
That doesn't answer my question, Berlin, so let me rephrase: do you need the time stamps in order to determine the simplification method? If so, please indicate precisely how they are needed, because so far they do not look essential. – whuber Jun 13 '13 at 13:08

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