This functionality does not run in MATLAB.
theta(x) represents the value of the theta series .
The theta series converges for all complex numbers x with positive real part.
Floating-point results are computed for floating-point arguments. For other arguments, the function returns symbolically with the imaginary part of complex numbers normalized to lie between zero and 2.
When called with a floating-point argument, the function is sensitive to the environment variable DIGITS which determines the numerical working precision.
The theta series takes on large values for small positive arguments. Small values are taken on near I:
theta(0.001), theta(0.001 + I)
Since the theta series is (2 i)-periodic, the imaginary part of complex arguments may be reduced:
theta(7 + 5*I)
For exact or symbolic arguments, a symbolic call is returned: