Method __add__

mne/label.py:325–393

Add Labels.

(self, other)

        return len(self.vertices)

    def __add__(self, other):
        """Add Labels."""
        _validate_type(other, (Label, BiHemiLabel), "other")
        if isinstance(other, BiHemiLabel):
            return other + self
        else:  # isinstance(other, Label)
            if self.subject != other.subject:
                raise ValueError(
                    "Label subject parameters must match, got "
                    f'"{self.subject}" and "{other.subject}". Consider setting the '
                    "subject parameter on initialization, or "
                    "setting label.subject manually before "
                    "combining labels."
                )
            if self.hemi != other.hemi:
                name = f"{self.name} + {other.name}"
                if self.hemi == "lh":
                    lh, rh = self.copy(), other.copy()
                else:
                    lh, rh = other.copy(), self.copy()
                color = _blend_colors(self.color, other.color)
                return BiHemiLabel(lh, rh, name, color)

        # check for overlap
        duplicates = np.intersect1d(self.vertices, other.vertices)
        n_dup = len(duplicates)
        if n_dup:
            self_dup = [np.where(self.vertices == d)[0][0] for d in duplicates]
            other_dup = [np.where(other.vertices == d)[0][0] for d in duplicates]
            if not np.all(self.pos[self_dup] == other.pos[other_dup]):
                err = (
                    f"Labels {repr(self.name)} and {repr(other.name)}: vertices "
                    "overlap but differ in position values"
                )
                raise ValueError(err)

            isnew = np.array([v not in duplicates for v in other.vertices])

            vertices = np.hstack((self.vertices, other.vertices[isnew]))
            pos = np.vstack((self.pos, other.pos[isnew]))

            # find position of other's vertices in new array
            tgt_idx = [np.where(vertices == v)[0][0] for v in other.vertices]
            n_self = len(self.values)
            n_other = len(other.values)
            new_len = n_self + n_other - n_dup
            values = np.zeros(new_len, dtype=self.values.dtype)
            values[:n_self] += self.values
            values[tgt_idx] += other.values
        else:
            vertices = np.hstack((self.vertices, other.vertices))
            pos = np.vstack((self.pos, other.pos))
            values = np.hstack((self.values, other.values))

        indcs = np.argsort(vertices)
        vertices, pos, values = vertices[indcs], pos[indcs, :], values[indcs]

        comment = f"{self.comment} + {other.comment}"