On Mon, Sep 15, 2014 at 11:55:11AM +0200, Mathias Müller wrote: > Ok, I got it work. I do not know why, but compiling against gwyddion > stable [0] works fine but for the nightly > snaptshot it doesn't. Moving to array position [1] works flawless with > the desired image output.
This looks like you are overwriting the stack somewhere. Running under valgrind may not help in this case but still it is worth trying. > But this leads to problem #2. I am applying the > gwy_data_field_fft_postprocess(data_field_fft_r,TRUE) ; to my > fft data obtained via: > > gwy_data_field_2dfft(data_field,NULL,data_field_fft_r,data_field_fft_i,GWY_WINDOWING_NONE,GWY_TRANSFORM_DIRECTION_FORWARD,GWY_INTERPOLATION_ROUND,TRUE,1) > ; > > results in the same data display, but with way larger x and y values. > > (0,0) is something like [2,57677e+09,2,56559e+09] (1/m I guess) It should not be ‘I guess’. It should actually invert the xy unit of the field. Does your field have correct lateral units to begin with? > and an example fft peak [1,7607e+09,2,57677e+09] which is in the > gwyddion fft-module (-0.82/nm,0)... 1/nm = 10⁹ 1/m So you seem to be off but the overall magnitude is right. > However,correcting the coorcdinates > with the zero position it fits quit well. But the corrected fft-output > is not centered at (0,0). > > Shouldn't this be done by the fft_postprocess() ? Yes, it should. The simplest use is probably in modules/process/fft_profile.c. See prof_psdf(). If it didn't set the origin right, the profile selection in the GUI would be wrong because one endpoint of the line is at (0,0) by definition. But it works for me. Regards, Yeti ------------------------------------------------------------------------------ Want excitement? Manually upgrade your production database. When you want reliability, choose Perforce Perforce version control. Predictably reliable. http://pubads.g.doubleclick.net/gampad/clk?id=157508191&iu=/4140/ostg.clktrk _______________________________________________ Gwyddion-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/gwyddion-users
