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I have a point layer with around 1.3 million features where one of the columns in the attributes table contains dates in the format YYYY-MM-DD.

Starting from an arbitrary date, say 2001-01-01, I would like to generate a series of maps which show all point features that have a date that is BEFORE that exogenously given starting date above and BEFORE every following month from then. In this example, I want to generate a map with all features before 2001-01-01, another one with all features before 2001-02-01, 2001-03-01 etc. Because I will have to generate many of such maps, I would like to automate this process.

To my knowledge, the atlas function will not do the job because it will iterate over each feature in the coverage layer. Also, I was not able to use the QGIS modeler with which I was hoping to make a selection by expression and then call the print composer.

I need to end up with the files map20010101.png, map20010201.png etc. saved to a folder for subsequent use. If that works via the print composer or not is not of importance.

Is there any functionality I was missing?

Software: QGIS 2.8.1, OS: MAX OSX


I have the same information in both, a string field and a date field. Making a selection works on the string field using the query builder, e.g. "date"<='2001-02-05', but not on the date field. The same applies to the Time Manager: The Time Manager works when I am using the string field, but not with the date field. However, that is not the problem for me. The problem is that the Time Manager makes "wrong selections" for my purposes, i.e. it selects observations that lie in intervals, e.g. "date">'2001-01-01' AND "date"='2001-01-31', but not "date"<='2001-01-01'.

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    This sounds like the QGIS version of gis.stackexchange.com/questions/144846 The solution there was, as underdark suggests, using a time-based tool (ArcGIS time slider) rather than atlas (ArcGIS data driven pages [DDP]). However one potential solution we discussed was using some sort of definition query on a bunch of stacked index features. It's not your points that would be the index, but a box that contains them all. Then each box copy has a definition query associated so it only loads points prior to whatever date. Don't know if that is possible or not, just a suggestion to explore. – Chris W May 24 '15 at 21:49
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The Time Manager plugin can be used to filter the points as you describe. It is worth noting though that it currently only supports exporting images at screen resolution.

To see the data for a specific month, make sure to set the Time frame size unit to month.

enter image description here

To view data incrementally, make sure to set the end time setting to accumulate features

enter image description here

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