def freeze(h, output_yaml, resolve, groups):
    """Output installed packages."""
    if not groups:
        groups = filter(lambda group: not group.lower().startswith("bower"),
                        h.requirements.keys())
    else:
        groups = [text_type.strip(group) for group in groups.split(",")]

    if output_yaml:
        for requirements in h.requirements.values():
            for requirement in requirements:
                if resolve and not requirement.version:
                    requirement.load_installed_version()
        click.echo(h.requirements.yaml)
    else:
        for group in groups:
            if not h.requirements[group]:
                continue
            click.echo("# {}".format(group))
            for requirement in h.requirements[group]:
                if resolve and not requirement.version:
                    requirement.load_installed_version()
                click.echo(str(requirement))
def setSaSS(self, lenp2, lenp3, lenp1):
        self.lenp2 = lenp2
        self.lenp3 = lenp3
        self.lenp1 = lenp1
        if(self.lenp1 > (self.lenp2 + self.lenp3)):
        #<CAB 夾角為 180 度, 三點共線且 A 介於 BC 之間
            ret = math.pi
        else :
            # <CAB 夾角為 0, 三點共線且 A 不在 BC 之間
            if((self.lenp1 < (self.lenp2 - self.lenp3)) or (self.lenp1 < (self.lenp3 - self.lenp2))):
                ret = 0.0
            else :
            # 透過餘絃定理求出夾角 <CAB 
                ret = math.acos(((self.lenp2 * self.lenp2 + self.lenp3 * self.lenp3) - self.lenp1 * self.lenp1) / (2 * self.lenp2 * self.lenp3))
        return ret