manualttest

manualttest.py

a=np.array([27.5, 21.0, 19.0, 23.6, 17.0, 17.9, 16.9, 20.1, 21.9, 22.6, 23.1, 19.6, 19.0, 21.7, 21.4])
b=np.array([27.1, 22.0, 20.8, 23.4, 23.4, 23.5, 25.8, 22.0, 24.8, 20.2, 21.9, 22.1, 22.9, 20.5, 24.4])
num_a,num_b=len(a),len(b)
print(a.var(),b.var())
>>>7.342933333333334, 3.5584888888888906
#Finding dof
dof=((a.var()/num_a) + (b.var()/num_b))**2/((a.var()**2/(num_a**2 * (num_a-1)))+(b.var()**2/(num_b**2 * (num_b-1))))
print(dof)
>>>24.988529290231416
#Finding t-value
t_value_diffvar= (a.mean()-b.mean())/sqrt(((((a-a.mean())**2).sum()/(num_a-1))/num_a)+(((b-b.mean())**2).sum()/(num_b-1))/num_b)
print(t_value_diffvar)
>>>-2.455356398286006