I'm using QGIS 2.4.0 and I have a shapefile of points with elevation data and X and Y coordinates. I'm using windows 7 OS.
The idea is to create a contour line SHP using my point data.
My question is: How do I start working on that issue? Is there a function? Is there a step by step process?
Using the Contour plugin. Generate isolines and/or filled contours a set of data points.
There are a number of tools in QGIS for generating contours, though most require a raster input rather than vector points. As such, your best bet is to use the Contour Lines From Points tool:
Models -> [Example Models] -> Contour lines from points
You have to set up the SAGA plugin. You can do it based on the documentation: QGIS Configuring external applications.
The tool takes a vector input and generates a contour line vector. You simply need to enter your points file and the attribute containing the 'z-value', an output grid resolution, and a contour interval.
Maybe it is too late to answer, but someone like me might have the same need.
I had a layer of points and I only wanted to visualize the perimeter or the contour. In QGIS 2.12 I only had to use the vector Research Tools "Polygon from Layer Extent" (from the vector menu) and voilà! The other option is to use a convex hull.In my case the first option (fastest) solve my problem as my points where regularly arranged in their extent.
