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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def I_minus_R(self,singular_value):
 """get I - R at singular value Parameters singular_value : int singular value to calc R at Returns ------- I - R : pyemu.Matrix identity matrix minus resolution matrix at singular_value """

        if self.__I_R is not None and singular_value == self.__I_R_sv:
            return self.__I_R
        else:
            if singular_value > self.jco.ncol:
                return self.parcov.zero
            else:
                #v2 = self.qhalfx.v[:, singular_value:]
                v2 = self.xtqx.v[:, singular_value:]
                self.__I_R = v2 * v2.T
                self.__I_R_sv = singular_value
                return self.__I_R