特殊関数のグラフ
y=normdist(x)
y=norminv(x)
y=chi2inv(x, 4)
y=chi2dist(x, 4)
y=tdist(x, 4)
y=tinv(x, 4)
y=fdist(x, 6, 4)
y=finv(x, 6, 4)
y=erf(x)