ENH/WIP: Alternative Constructor for getting new Raw instances from e…

…xisting plus modified data

- use case #1 mixing of ica denoised data
- use case #2 other filtering operations
- use case #3 'ABC' for reading in externally processed data

I added assert statement that makes sure the dimensionality of the external data and the original fiff is compatible.

What do you think on this?

mne/fiff/raw.py

@@ -11,6 +11,7 @@
 
 import numpy as np
 from scipy.signal import hilbert
+from copy import deepcopy
 
 from .constants import FIFF
 from .open import fiff_open
@@ -903,6 +904,58 @@ def _update_projector(self):
             return False
 
 
+class RawFromMerge(Raw):
+    """ Initializes new raw instance from exisiting raw and custom data
+    Paramerters
+    -----------
+    raw : instance of mne.fiff.Raw
+        existing raw instance
+    data : instance of numpy.core.ndarray
+        processed data matching the data contained by raw
+
+    Attributes
+    ----------
+        See __doc__ of mne.fiff.Raw
+    """
+    def __init__(self, raw, data, info=None):
+
+        print 'Initializing raw object from merge with custom data.'
+
+        ntsl = (raw.last_samp - raw.first_samp) + 1
+        nchan = len(raw.ch_names)
+        assert (nchan, ntsl) == data.shape
+
+        raw = deepcopy(raw)
+        if info == None:
+            info = raw.info
+
+        self.info = info
+        self._data = data
+        self.first_samp, self.last_samp = raw.first_samp, raw.last_samp
+        cals = np.zeros(info['nchan'])
+        for k in range(info['nchan']):
+            cals[k] = info['chs'][k]['range'] * \
+                      info['chs'][k]['cal']
+
+        self.cals = raw.cals
+        self.rawdir = raw.rawdir
+        self.proj = raw.proj
+        self.comp = raw.comp
+
+        self.verbose = True
+        if self.verbose:
+            print '    Range : %d ... %d =  %9.3f ... %9.3f secs' % (
+                       self.first_samp, self.last_samp,
+                       float(self.first_samp) / info['sfreq'],
+                       float(self.last_samp) / info['sfreq'])
+            print 'Ready.'
+        self.fid = None
+        self._preloaded = True
+        self._times = np.arange(self.first_samp,
+            self.last_samp + 1) / info['sfreq']
+        del raw
+
+
 class _RawShell():
     """Used for creating a temporary raw object"""
     def __init__(self):