def grab_data(self, f_start=None, f_stop=None, t_start=None, t_stop=None, if_id=<NUM_LIT:0>):
if f_start is None:<EOL><INDENT>f_start = self.freqs[<NUM_LIT:0>]<EOL><DEDENT>if f_stop is None:<EOL><INDENT>f_stop = self.freqs[-<NUM_LIT:1>]<EOL><DEDENT>i0 = np.argmin(np.abs(self.freqs - f_start))<EOL>i1 = np.argmin(np.abs(self.freqs - f_stop))<EOL>if i0 < i1:<EOL><INDENT>plot_f    = self.freqs[i0:i1 + <NUM_LIT:1>]<EOL>plot_data = np.squeeze(self.data[t_start:t_stop, ..., i0:i1 + <NUM_LIT:1>])<EOL><DEDENT>else:<EOL><INDENT>plot_f    = self.freqs[i1:i0 + <NUM_LIT:1>]<EOL>plot_data = np.squeeze(self.data[t_start:t_stop, ..., i1:i0 + <NUM_LIT:1>])<EOL><DEDENT>return plot_f, plot_data<EOL>
Extract a portion of data by frequency range.

        Args:
            f_start (float): start frequency in MHz
            f_stop (float): stop frequency in MHz
            if_id (int): IF input identification (req. when multiple IFs in file)

        Returns:
            (freqs, data) (np.arrays): frequency axis in MHz and data subset