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We are capturing sample points from survey maps. In between two points we have to introduce another point (as in fig), like - if the sample points are 42 and 42.5 we have to introduce another point with value 42.5. Is it possible to automate this process in QGIS using any plugin ?

enter image description here

3 Answers 3

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What are the distances between the columns? The distances between the points in one column are the same? I changed a bit the steps above.

  • create buffer with more than half way radius
  • cut the overlapping areas as separate polygons
  • create a calculated field to represent the area sizes. If the distances between point to point in column and column to column are different than you should get different area sizes. Check what is your average size of "point to point in column" polygons
  • query to select this sizes and generate the centroids based on selection or query to select the positive false intersections and delete them and generate the centroids on the rest.
  • polygons in QGIS) generate the centroids of these polygons

Hope it helps.

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  • Will definitely try this and let you know. Currently am doing this in excel.
    – joseph_k
    May 6, 2015 at 8:34
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If you connect your original points with lines (maybe using the points2one or PonitConnector plugin), you can:

  1. buffer those lines with a small value
  2. calculate the centroid of the buffers

You still have to calculate the value at the new points.


Alternatively, using an excel table with coordinates and values:

x = ( x1 + x2 ) / 2
y = ( y1 + y2 ) / 2
v = ( v1 + v2 ) / 2

This requires the neighbouring points in one line, or following lines.

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  • Already started to use excel for this. Exported the table to xls and introduced empty rows alternatively and got the average between two cells. Worked like a charm
    – joseph_k
    May 6, 2015 at 8:33
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I have an idea what may can help you, but I couldnt test it (I am not sure where are the necessary functions in qgis, but they should be available because the steps are built up from general GIS concepts)

I presume (based on the picture) the distance between the points are constant or near constant. Steps:

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  • It worked. But the thing is, we have 15 columns of such points and it didn't work well for that scenario. It worked great for a single line of points.
    – joseph_k
    May 4, 2015 at 5:08

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