code: def mvstdtprob(a, b, R, df, ieps=1e-5, quadkwds=None, mvstkwds=None):
      """
      Probability of rectangular area of standard t distribution
  
      assumes mean is zero and R is correlation matrix
  
      Notes
      -----
      This function does not calculate the estimate of the combined error
      between the underlying multivariate normal probability calculations
      and the integration.
      """
      kwds = dict(
          args=(a, b, R, df), epsabs=1e-4, epsrel=1e-2, limit=150
      )
      if quadkwds is not None:
          kwds.update(quadkwds)
      lower, upper = chi.ppf([ieps, 1 - ieps], df)
      res, err = integrate.quad(funbgh2, lower, upper, **kwds)
      prob = res * bghfactor(df)
      return prob
  
file_path: statsmodels/statsmodels/sandbox/distributions/multivariate.py
imports: import numpy
  from scipy import integrate, stats, special
  from scipy.stats import chi
  from .extras import mvstdnormcdf
  from numpy import exp
  from numpy import log
  from scipy.special import gamma
  from scipy.special import gammaln
label_desc: Use image node_id 7 for calling a global function with example usage: mvstdtprob(a, b, R, df, ieps, quadkwds, mvstkwds) and returns: prob