I am getting out graphs with no data on them, I was given guidance to flatten or use receptions$[0,$:$]$ on the receptions but however I am doing it is not working.

Code so far.

import numpy as np

import matplotlib.pyplot as plt

npz$\_$file $=$ np$.$load$(\text{'}$proj$\_$part$3.$npz$\text{'})$

fs$=$npz$\_$file$[\text{'}$fs$\text{'}]$

starttime$=$npz$\_$file$[\text{'}$starttime$\text{'}]$

nreceptions$=$npz$\_$file$[\text{'}$nreceptions$\text{'}]$

receptions$=$npz$\_$file$[\text{'}$receptions$\text{'}]$

fc$=$npz$\_$file$[\text{'}$fc$\text{'}]$

pulsetype$=$npz$\_$file$[\text{'}$pulsetype$\text{'}]$

sigdur$=$npz$\_$file$[\text{'}$sigdur$\text{'}]$

time$\_$vector $=$ np$.$arange$($starttime$,$ starttime $+$ sigdur, $1/$fs$)$

#receptions$[0,$:$]$

#receptions.flatten$()$

plt$.$plot$($time$\_$vector, receptions$)$

plt$.$title$(\text{'}$Recieved Data vs Time'$)$

plt$.$xlabel$(\text{'}$Time $($s$)\text{'})$

plt$.$ylabel$(\text{'}$Recieved Data'$)$

plt$.$show$()$

dB$\_$dynrange$=40$

plt$.$figure$($figsize$=(10,6))$

spec,freqs,tspec,im$=$plt$.$specgram$($receptions$,$ NFFT$=256,$ Fs$=$fs$,$ mode$=$'magnitude', scale$=\text{'}$dB$\text{'},$ sides$=$'twosided'$)$

plt$.$colorbar$($label$=$'Magnitude $($dB$)\text{'})$

plt$.$xlabel$(\text{'}$Time $($s$)\text{'})$

plt$.$ylabel$(\text{'}$Frequency $($Hz$)\text{'})$

plt$.$title$(\text{'}$Two$-$Sided Spectrogram of Received Data'$)$

plt$.$show$()$