estimate variance components and fixed effects
        from a single trait model having only two terms

def estimateHeritabilities(self, K, verbose=False):
        """
        estimate variance components and fixed effects
        from a single trait model having only two terms
        """
        
        # Fit single trait model
        varg  = SP.zeros(self.P)
        varn  = SP.zeros(self.P)
        fixed = SP.zeros((1,self.P))
        
        for p in range(self.P):
            y = self.Y[:,p:p+1]
            lmm = limix.CLMM()
            lmm.setK(K)
            lmm.setSNPs(SP.ones((K.shape[0],1)))
            lmm.setPheno(y)
            lmm.setCovs(SP.zeros((K.shape[0],1)))
            lmm.setVarcompApprox0(-20, 20, 1000)
            lmm.process()
            delta = SP.exp(lmm.getLdelta0()[0,0])
            Vtot  = SP.exp(lmm.getLSigma()[0,0])
    
            varg[p] = Vtot
            varn[p] = delta*Vtot
            fixed[:,p] = lmm.getBetaSNP()
    
            if verbose: print(p)
    
        sth = {}
        sth['varg']  = varg
        sth['varn']  = varn
        sth['fixed'] = fixed

        return sth