On Mon, Jan 27, 2014 at 04:22:49AM -0700, Salman Manzoor wrote: > I am trying to find a slope distribution (gwyddion also refers to this as > Inclination graph) from a height matrix that I obtained with AFM. Could > someone explain how does gwyddion exactly calculate the slope at each pixel > (without local plane fitting)? And what it does when you select the 'Use > Local Plane Fitting'? And when you use Local Plane Fitting, there is an > option to change the number of pixels, are these pixels selected as a > square neighbourhood or linear row/column pixels?
The module is decribed here http://gwyddion.net/documentation/user-guide-en/statistical-analysis.html#slope-distribution The derivatives used when local plane fitting is not used are calculated from the minimum neighbourhood, i.e. the four neighbour pixels that share a side with the central one, with the elementary discrete differentation formula. For local plane fitting, the neighbourhood is square and centered on the pixel for odd sizes, shifted half-pixel up and to the left for even sizes. Regards, Yeti ------------------------------------------------------------------------------ CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments & Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431&iu=/4140/ostg.clktrk _______________________________________________ Gwyddion-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/gwyddion-users
