How to get the data of gr.probe_signal_vf

Dear All,
I’m a PhD student at De Montfort University UK and I’m new to gnuradio.
I
was using gr.probe_signal_vf & gr.probe_signal_vc to obtain data for
USRP and fft magnitude but when i used the dot value() attribute to get
the data, i received an error message saying the object of
gr.probe_signal_vf has no
value attribute. please kindly help. Thanks
Sunday

You want the “level” attribute not “value”.

On Tue, Sep 3, 2013 at 9:22 AM, sunday iliya