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cadnano_segments

Module documentation for cadnano_segments.

API Reference

cadnano_part

Bases: SegmentModel

Source code in mrdna/readers/cadnano_segments.py
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class cadnano_part(SegmentModel):
    def __init__(self, part, 
                 **kwargs
    ):
        self.part = part
        self.lattice_type = _get_lattice(part)

        self._cadnano_part_to_segments(part)
        # SegmentModel.__init__(self,...)
        # self.segments = [seg for hid,segs in self.helices.items() for seg in segs]
        self.segments = [seg for hid,segs in sorted(self.helices.items()) for seg in segs]
        self._add_intrahelical_connections()
        self._add_crossovers()
        self._add_prime_ends()
        SegmentModel.__init__(self, self.segments,
                              **kwargs)

    def _get_helix_angle(self, helix_id, indices):
        """ Get "start_orientation" for helix """
        # import ipdb
        # ipdb.set_trace()

        """ FROM CADNANO2.5
        + angle is CCW
        - angle is CW
        Right handed DNA rotates clockwise from 5' to 3'
        we use the convention the 5' end starts at 0 degrees
        and it's pair is minor_groove_angle degrees away
        direction, hence the minus signs.  eulerZ
        """

        hp, bpr, tpr, eulerZ, mgroove = self.part.vh_properties.loc[helix_id,
                                                                    ['helical_pitch',
                                                                     'bases_per_repeat',
                                                                     'turns_per_repeat',
                                                                     'eulerZ',
                                                                     'minor_groove_angle']]
        twist_per_base = tpr*360./bpr
        # angle = eulerZ - twist_per_base*indices + 0.5*mgroove + 180
        angle = eulerZ + twist_per_base*indices - 0.5*mgroove
        return angle

    def _cadnano_part_to_segments(self,part):
        try:
            from cadnano.cnenum import PointType
        except:
            try:
                from cadnano.proxies.cnenum import PointType
            except:
                from cadnano.proxies.cnenum import PointEnum as PointType

        segments = dict()
        self.helices = helices = dict()
        self.helix_ranges = helix_ranges = dict()

        props = part.getModelProperties().copy()

        if props.get('point_type') == PointType.ARBITRARY:
            # TODO add code to encode Parts with ARBITRARY point configurations
            raise NotImplementedError("Not implemented")
        else:
            try:
                vh_props, origins = part.helixPropertiesAndOrigins()
            except:
                origins = {hid:part.getVirtualHelixOrigin(hid)[:2] for hid in part.getidNums()}

        self.origins = origins

        vh_list = []
        strand_list = []
        xover_list = []
        self.xovers_from = dict()
        self.xovers_to = dict()

        try:
            numHID = part.getMaxIdNum() + 1
        except:
            numHID = part.getIdNumMax() + 1

        for id_num in range(numHID):
            try:
                offset_and_size = part.getOffsetAndSize(id_num)
            except:
                offset_and_size = None
            if offset_and_size is None:
                ## Add a placeholder for empty helix
                vh_list.append((id_num, 0))
                strand_list.append(None)
            else:
                offset, size = offset_and_size
                vh_list.append((id_num, size))
                fwd_ss, rev_ss = part.getStrandSets(id_num)
                fwd_idxs, fwd_colors  = fwd_ss.dump(xover_list)
                rev_idxs, rev_colors  = rev_ss.dump(xover_list)
                strand_list.append((fwd_idxs, rev_idxs))

            self.xovers_from[id_num] = []
            self.xovers_to[id_num] = []

        for xo in xover_list:
            h1,f1,z1,h2,f2,z2 = xo
            self.xovers_from[h1].append(xo)
            self.xovers_to[h2].append(xo)

        ## Get lists of 5/3prime ends
        strands5 = [o.strand5p() for o in part.oligos()]
        strands3 = [o.strand3p() for o in part.oligos()]

        self._5prime_list = [(s.idNum(),s.isForward(),s.idx5Prime()) for s in strands5]
        self._3prime_list = [(s.idNum(),s.isForward(),s.idx3Prime()) for s in strands3]

        ## Get dictionary of insertions 
        self.insertions = allInsertions = part.insertions()
        self.strand_occupancies = dict()

        ## Build helices 
        for hid in range(numHID):
            # print("Working on helix",hid)
            helices[hid] = []
            helix_ranges[hid] = []
            self.strand_occupancies[hid] = []

            helixStrands = strand_list[hid]
            if helixStrands is None: continue

            ## Build list of tuples containing (idx,length) of insertions/skips
            insertions = sorted( [(i[0],i[1].length()) for i in allInsertions[hid].items()],
                                 key=lambda x: x[0] )

            ## TODO: make the following code (until "regions = ...") more readable
            ## Build list of strand ends and list of mandatory node locations
            ends1,ends2 = self._helixStrandsToEnds(helixStrands)

            ## Find crossovers for this helix
            reqNodeZids = sorted(list(set( ends1 + ends2 ) ) )

            ## Build lists of which nt sites are occupied in the helix
            strandOccupancies = [ [x for i in range(0,len(e),2) 
                                   for x in range(e[i],e[i+1]+1)] 
                                  for e in (ends1,ends2) ]
            self.strand_occupancies[hid] = strandOccupancies

            ends1,ends2 = [ [(e[i],e[i+1]) for i in range(0,len(e),2)] for e in (ends1,ends2) ]

            regions = combineRegionLists(ends1,ends2)

            ## Split regions in event of ssDNA crossover
            split_regions = []
            for zid1,zid2 in regions:
                zMid = int(0.5*(zid1+zid2))
                if zMid in strandOccupancies[0] and zMid in strandOccupancies[1]:
                    split_regions.append( (zid1,zid2) )
                else:
                    is_fwd = zMid in strandOccupancies[0]
                    ends = [z for h,f,z in self._get_crossover_locations( hid, range(zid1+1,zid2), is_fwd )]
                    z1 = zid1
                    for z in sorted(ends):
                        z2 = z
                        if z2 > z1:
                            split_regions.append( (z1,z2) )
                            z1 = z2+1
                    z2 = zid2
                    split_regions.append( (z1,z2) )

            # if hid == 43:
            #     import pdb
            for zid1,zid2 in split_regions:
                zMid = int(0.5*(zid1+zid2))
                assert( zMid in strandOccupancies[0] or zMid in strandOccupancies[1] )

                bp_to_zidx = []
                insertion_dict = {idx:length for idx,length in insertions}
                for i in range(zid1,zid2+1):
                    if i in insertion_dict:
                        l = insertion_dict[i]
                    else:
                        l = 0
                    for j in range(i,i+1+l):
                        bp_to_zidx.append(i)
                numBps = len(bp_to_zidx)

                # print("Adding helix with length",numBps,zid1,zid2)

                name = "%d-%d" % (hid,len(helices[hid]))
                # "H%03d" % hid
                kwargs = dict(name=name, segname=name, occupancy=hid)

                posargs1 = dict( start_position = self._get_cadnano_position(hid,zid1-0.25),
                                 end_position   = self._get_cadnano_position(hid,zid2+0.25) )
                posargs2 = dict( start_position = posargs1['end_position'],
                                 end_position = posargs1['start_position'])

                ## TODO get sequence from cadnano api
                if zMid in strandOccupancies[0] and zMid in strandOccupancies[1]:
                    kwargs['num_bp'] = numBps
                    _angle = self._get_helix_angle(hid, zid1)
                    start_orientation = rotationAboutAxis(np.array((0,0,1)), _angle)
                    seg = DoubleStrandedSegment(**kwargs,**posargs1, start_orientation = start_orientation)
                elif zMid in strandOccupancies[0]:
                    kwargs['num_nt'] = numBps
                    seg = SingleStrandedSegment(**kwargs,**posargs1)
                elif zMid in strandOccupancies[1]:
                    kwargs['num_nt'] = numBps
                    seg = SingleStrandedSegment(**kwargs,**posargs2)
                else:
                    raise Exception("Segment could not be found")

                seg._cadnano_helix = hid
                seg._cadnano_start = zid1
                seg._cadnano_end   = zid2
                seg._cadnano_bp_to_zidx = bp_to_zidx

                def callback(segment):
                    for b in segment.beads:
                        bp = int(round(b.get_nt_position(segment)))
                        if bp < 0: bp = 0
                        if bp >= segment.num_nt: bp = segment.num_nt-1
                        try:
                            b.beta = segment._cadnano_bp_to_zidx[bp]
                            if 'orientation_bead' in b.__dict__:
                                b.orientation_bead.beta = segment._cadnano_bp_to_zidx[bp]
                        except:
                            pass
                seg._generate_bead_callbacks.append(callback)

                def atomic_callback(nucleotide, bp_to_zidx=bp_to_zidx):
                    nt = nucleotide
                    segment = nucleotide.parent.segment
                    bp = int(round(segment.contour_to_nt_pos( nt.contour_position )))
                    if bp < 0: bp = 0
                    if bp >= segment.num_nt: bp = segment.num_nt-1
                    try:
                        nt.beta = bp_to_zidx[bp]
                        nt.parent.occupancy = segment.occupancy
                    except:
                        pass
                seg._generate_nucleotide_callbacks.append(atomic_callback)


                helices[hid].append( seg )
                helix_ranges[hid].append( (zid1,zid2) )

    def _get_cadnano_position(self, hid, zid):
        return [10*a for a in self.origins[hid]] + [-3.4*zid]

    def _helixStrandsToEnds(self, helixStrands):
        """Utility method to convert cadnano strand lists into list of
        indices of terminal points"""

        endLists = [[],[]]
        for endList, strandList in zip(endLists,helixStrands):
            lastStrand = None
            for s in strandList:
                if lastStrand is None:
                    ## first strand
                    endList.append(s[0])
                elif lastStrand[1] != s[0]-1: 
                    assert( s[0] > lastStrand[1] )
                    endList.extend( [lastStrand[1], s[0]] )
                lastStrand = s
            if lastStrand is not None:
                endList.append(lastStrand[1])
        return endLists

    def _helix_strands_to_segment_ranges(self, helix_strands):
        """Utility method to convert cadnano strand lists into list of
        indices of terminal points"""
        def _join(strands):
            ends = []
            lastEnd = None
            for start,end in strands:
                if lastEnd is None:
                    ends.append([start])
                elif lastEnd != start-1:
                    ends[-1].append(lastEnd)
                    ends.append([start])
                lastEnd = end
            if lastEnd is not None:
                ends[-1].append(lastEnd)
            return ends

        s1,s2 = [_join(s) for s in helix_strands]
        i = j = 0

        ## iterate through strands
        while i < len(s1) and j < len(s2):
            min(s1[i][0],s2[j][0])

    def _get_segment(self, hid, zid):
        ## TODO: rename these variables to segments
        segs = self.helices[hid]
        ranges = self.helix_ranges[hid]
        for i in range(len(ranges)):
            zmin,zmax = ranges[i]
            if zmin <= zid and zid <= zmax:
                return segs[i]
        raise Exception("Could not find segment in helix %d at position %d" % (hid,zid))

    def _get_nucleotide(self, hid, zid):
        raise Exception("Deprecated")
        seg = self._get_segment(hid,zid)
        sid = self.helices[hid].index(seg)
        zmin,zmax = self.helix_ranges[hid][sid]

        nt = zid-zmin

        ## Find insertions
        # TODO: for i in range(zmin,zid+1): ?
        for i in range(zmin,zid):
            if i in self.insertions[hid]:
                nt += self.insertions[hid][i].length()
        return nt

    def _get_segment_nucleotide(self, hid, zid, get_forward_location=False):
        """ returns segments and zero-based nucleotide index """
        seg = self._get_segment(hid,zid)
        sid = self.helices[hid].index(seg)
        zmin,zmax = self.helix_ranges[hid][sid]

        zMid = int(0.5*(zmin+zmax))
        occ = self.strand_occupancies[hid]
        ins = self.insertions[hid]

        ## TODO combine if/else when nested TODO is resolved
        # if zid in self.insertions[hid]:
        #     import pdb
        #     pdb.set_trace()

        if (zMid not in occ[0]) and (zMid in occ[1]):
            ## reversed ssDNA strand
            nt = zmax-zid
            # TODO: for i in range(zmin,zid+1): ?
            for i in range(zid,zmax+1):
                if i in self.insertions[hid]:
                    nt += self.insertions[hid][i].length()
        else:
            ## normal condition
            if get_forward_location:
                while zid in ins and ins[zid].length() < 0 and zid <= zmax:
                    zid+=1
            # else:
            #     while zid in ins and ins[zid].length() > 0 and zid >= zmax:
            #         zid-=1
            nt = zid-zmin
            for i in range(zmin,zid):
                if i in ins:
                    nt += ins[i].length()

            if not get_forward_location and zid in ins:
                nt += ins[zid].length()

        ## Find insertions
        return seg, nt



    """ Routines to add connnections between helices """
    def _add_intrahelical_connections(self):
        for hid,segs in self.helices.items():
            occ = self.strand_occupancies[hid]
            for i in range(len(segs)-1):
                seg1,seg2 = [segs[j] for j in (i,i+1)]
                if isinstance(seg1,SingleStrandedSegment) and isinstance(seg2,SingleStrandedSegment):
                    continue
                r1,r2 = [self.helix_ranges[hid][j] for j in (i,i+1)]
                if r1[1]+1 == r2[0]:
                    ## TODO: handle nicks that are at intrahelical connections(?)
                    zmid1 = int(0.5*(r1[0]+r1[1]))
                    zmid2 = int(0.5*(r2[0]+r2[1]))

                    ## TODO: validate
                    if zmid1 in occ[0] and zmid2 in occ[0]:
                        seg1.connect_end3(seg2.start5)

                    if zmid1 in occ[1] and zmid2 in occ[1]:
                        if zmid1 in occ[0]:
                            end = seg1.end5
                        else:
                            end = seg1.start5
                        if zmid2 in occ[0]:
                            seg2.connect_start3(end)
                        else:
                            seg2.connect_end3(end)


    def _get_crossover_locations(self, helix_idx, nt_idx_range, fwd_strand=None):
        xos = []
        def append_if_in_range(h,f,z):
            if fwd_strand in (None,f) and z in nt_idx_range:
                xos.append((h,f,z))

        for xo in self.xovers_from[helix_idx]:
            ## h1,f1,z1,h2,f2,z2 = xo[3:]

            append_if_in_range(*xo[:3])
        for xo in self.xovers_to[helix_idx]:
            append_if_in_range(*xo[3:])
        return xos

    def _add_crossovers(self):
        for hid,xos in self.xovers_from.items():
            for h1,f1,z1,h2,f2,z2 in xos:
                seg1, nt1 = self._get_segment_nucleotide(h1,z1,not f1)
                seg2, nt2 = self._get_segment_nucleotide(h2,z2,f2)
                ## TODO: use different types of crossovers
                ## fwd?
                ## 5'-to-3' direction
                if isinstance(seg1, SingleStrandedSegment): f1 = True
                if isinstance(seg2, SingleStrandedSegment): f2 = True
                seg1.add_crossover(nt1,seg2,nt2,[f1,f2])

    def _add_prime_ends(self):
        for h,fwd,z in self._5prime_list:
            seg, nt = self._get_segment_nucleotide(h,z, fwd)
            if isinstance(seg, SingleStrandedSegment): fwd = True
            # print("adding 5prime",seg.name,nt,fwd)
            seg.add_5prime(nt,fwd)

        for h,fwd,z in self._3prime_list:
            seg, nt = self._get_segment_nucleotide(h,z, not fwd)
            if isinstance(seg, SingleStrandedSegment): fwd = True
            # print("adding 3prime",seg.name,nt,fwd)
            seg.add_3prime(nt,fwd) 

    def get_bead(self, hid, zid):
        # get segment, get nucleotide,
        seg, nt = self._get_segment_nucleotide(h,z)
        # return seg.get_nearest_bead(seg,nt / seg.num_nt)
        return seg.get_nearest_bead(seg,nt / (seg.num_nt-1))

combineCompactRegionLists(loHi1, loHi2, intersect=False)

Combines two lists of (lo,hi) pairs specifying regions within a compact integer set into a single list of regions.

examples: loHi1 = [[0,4],[5,7]] loHi2 = [[2,4],[5,9]] out = [(0, 1), (2, 4), (5, 7), (8, 9)]

loHi1 = [[0,3],[5,7]] loHi2 = [[2,4],[5,9]] out = [(0, 1), (2, 3), (4, 4), (5, 7), (8, 9)]

Source code in mrdna/readers/cadnano_segments.py
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def combineCompactRegionLists(loHi1,loHi2,intersect=False):

    """Combines two lists of (lo,hi) pairs specifying regions within a
    compact integer set into a single list of regions.

    examples:
    loHi1 = [[0,4],[5,7]]
    loHi2 = [[2,4],[5,9]]
    out = [(0, 1), (2, 4), (5, 7), (8, 9)]

    loHi1 = [[0,3],[5,7]]
    loHi2 = [[2,4],[5,9]]
    out = [(0, 1), (2, 3), (4, 4), (5, 7), (8, 9)]
    """

    ## Validate input
    for l in (loHi1,loHi2):
        ## Assert each region in lists is sorted
        for pair in l:
            assert(len(pair) == 2)
            assert(pair[0] <= pair[1])
        ## Assert lists are compact
        for pair1,pair2 in zip(l[::2],l[1::2]):
            assert(pair1[1]+1 == pair2[0])

    if len(loHi1) == 0:
        if intersect:
            return []
        else:
            return loHi2
    if len(loHi2) == 0:
        if intersect:
            return []
        else:
            return loHi1

    ## Find the ends of the region
    lo = min( [loHi1[0][0], loHi2[0][0]] )
    hi = max( [loHi1[-1][1], loHi2[-1][1]] )

    ## Make a list of indices where each region will be split
    splitAfter = []
    for l,h in loHi2:
        if l != lo:
            splitAfter.append(l-1)
        if h != hi:
            splitAfter.append(h)

    for l,h in loHi1:
        if l != lo:
            splitAfter.append(l-1)
        if h != hi:
            splitAfter.append(h)
    splitAfter = sorted(list(set(splitAfter)))

    # print("splitAfter:",splitAfter)

    split=[]
    last = -2
    for s in splitAfter:
        split.append(s)
        last = s

    # print("split:",split)
    returnList = [(i+1,j) if i != j else (i,j) for i,j in zip([lo-1]+split,split+[hi])]

    if intersect:
        lo = max( [loHi1[0][0], loHi2[0][0]] )
        hi = min( [loHi1[-1][1], loHi2[-1][1]] )
        returnList = [r for r in returnList if r[0] >= lo and r[1] <= hi]

    # print("loHi1:",loHi1)
    # print("loHi2:",loHi2)
    # print(returnList,"\n")
    return returnList

combineRegionLists(loHi1, loHi2, intersect=False)

Combines two lists of (lo,hi) pairs specifying integer regions a single list of regions.

Source code in mrdna/readers/cadnano_segments.py
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def combineRegionLists(loHi1,loHi2,intersect=False):

    """Combines two lists of (lo,hi) pairs specifying integer
    regions a single list of regions.  """

    ## Validate input
    for l in (loHi1,loHi2):
        ## Assert each region in lists is sorted
        for pair in l:
            assert(len(pair) == 2)
            assert(pair[0] <= pair[1])

    if len(loHi1) == 0:
        if intersect:
            return []
        else:
            return loHi2
    if len(loHi2) == 0:
        if intersect:
            return []
        else:
            return loHi1

    ## Break input into lists of compact regions
    compactRegions1,compactRegions2 = [[],[]]
    for compactRegions,loHi in zip(
            [compactRegions1,compactRegions2],
            [loHi1,loHi2]):
        tmp = []
        lastHi = loHi[0][0]-1
        for lo,hi in loHi:
            if lo-1 != lastHi:
                compactRegions.append(tmp)
                tmp = []
            tmp.append((lo,hi))
            lastHi = hi
        if len(tmp) > 0:
            compactRegions.append(tmp)

    ## Build result
    result = []
    region = []
    i,j = [0,0]
    compactRegions1.append([[1e10]])
    compactRegions2.append([[1e10]])
    while i < len(compactRegions1)-1 or j < len(compactRegions2)-1:
        cr1 = compactRegions1[i]
        cr2 = compactRegions2[j]

        ## initialize region
        if len(region) == 0:
            if cr1[0][0] <= cr2[0][0]:
                region = cr1
                i += 1
                continue
            else:
                region = cr2
                j += 1
                continue

        if region[-1][-1] >= cr1[0][0]:
            region = combineCompactRegionLists(region, cr1, intersect=False)
            i+=1
        elif region[-1][-1] >= cr2[0][0]:
            region = combineCompactRegionLists(region, cr2, intersect=False)
            j+=1
        else:
            result.extend(region)
            region = []

    assert( len(region) > 0 )
    result.extend(region)
    result = sorted(result)

    # print("loHi1:",loHi1)
    # print("loHi2:",loHi2)
    # print(result,"\n")

    if intersect:
        lo = max( [loHi1[0][0], loHi2[0][0]] )
        hi = min( [loHi1[-1][1], loHi2[-1][1]] )
        result = [r for r in result if r[0] >= lo and r[1] <= hi]

    return result

read_model(json_data, sequence=None, fill_sequence='T', **kwargs)

Read in data

Source code in mrdna/readers/cadnano_segments.py
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def read_model(json_data, sequence=None, fill_sequence='T', **kwargs):
    """ Read in data """
    part = decode_cadnano_part(json_data)
    model = cadnano_part(part,
                         **kwargs)

    # TODO
    # try:
    #     model.set_cadnano_sequence()
    # finally:
    #     ...
    #     if sequence is not None and len() :
    #         model.strands[0].set_sequence(seq)

    if sequence is None or len(sequence) == 0:
        ## default m13mp18
        model.set_sequence(m13seq,force=False, fill_sequence=fill_sequence)
    else:
        model.set_sequence(sequence, fill_sequence=fill_sequence)

    return model