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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 check_roundoff(self, rtol=0.25, atol=1e-6):
 """ Check for roundoff errors in fit.p. Compares standard deviations from fit.p and fit.palt to see if they agree to within relative tolerance ``rtol`` and absolute tolerance ``atol``. Generates a warning if they do not (in which case an SVD cut might be advisable). """

        psdev = _gvar.sdev(self.p.flat)
        paltsdev = _gvar.sdev(self.palt.flat)
        if not numpy.allclose(psdev, paltsdev, rtol=rtol, atol=atol):
            warnings.warn("Possible roundoff errors in fit.p; try svd cut.")