adc (expanded=True): do not rely on n_sig.

When converting physical to digital sample arrays, all the information
we need is contained in self.e_p_signal, self.adc_gain, self.baseline,
and self.fmt.

We don't need to rely on self.n_sig here, and we don't use n_sig in
the expanded=False case, so for consistency, don't use n_sig in the
expanded=True case either.

Author: Benjamin Moody

wfdb/io/_signal.py

@@ -561,9 +561,9 @@ def adc_inplace_2d(p_signal):
         # Do inplace conversion and set relevant variables.
         if inplace:
             if expanded:
-                for ch in range(self.n_sig):
+                for ch, ch_p_signal in enumerate(self.e_p_signal):
                     ch_d_signal = adc_inplace_1d(
-                        self.e_p_signal[ch],
+                        ch_p_signal,
                         self.adc_gain[ch],
                         self.baseline[ch],
                         d_nans[ch],
@@ -579,9 +579,9 @@ def adc_inplace_2d(p_signal):
         else:
             if expanded:
                 d_signal = []
-                for ch in range(self.n_sig):
+                for ch, ch_p_signal in enumerate(self.e_p_signal):
                     ch_d_signal = adc_inplace_1d(
-                        self.e_p_signal[ch].copy(),
+                        ch_p_signal.copy(),
                         self.adc_gain[ch],
                         self.baseline[ch],
                         d_nans[ch],