Re: [Discuss-gnuradio] fft display frequency spotting

[Chuck Swiger]

At 01:52 PM 8/3/2005 -0700, you wrote:


> There's a method in gr-wxgui/src/python/plot.py that maps mouse x/y to
> model space: GetClosestPoint.  The plot.py builtin example uses it.
>
> Using it will allow you to remove the magic numbers and it also should
> work when you resize the window.


Not a biggie (I'm happy with the hardwired magic numbers ;)
but GetClosetPoint (sic)  doesn't seem to work as advertised.

Using fftsink.py as a testbed, feeding mouse event.GetPosition() to
self.sink2.win.GetClosetPoint()  returns nothing expected, whether
pointScaled=True or False.  With 'True' I indeed get the closest
point on the curve - but only when using plotted values (in the range of
GetXCurrentRange()  and GetYCurrentRange() , in this case
100 < x < 110 khz and 20 < y < 100 db)  - and not with mouse window
position values.


Anyway, some uses of a clickable fft display:
- setting carrier point for demodulation
- setting filter passbands
- slap a notch filter on some lid tuning up in your passband (an algorithm
for an 'auto-notch' would be even better)

--Chuck