DLMF:

Figure 21.4.2 (See in context.)

Figure 21.4.2: $\realpart{\mathop{\hat{\theta}\/}\nolimits\!\left(x+iy,0\middle|\boldsymbol{{% \Omega}}_{1}\right)}$ , $0\leq x\leq 1$ , $0\leq y\leq 5$ . (The imaginary part looks very similar.)

Annotations:

Symbols:: $\mathop{\hat{\theta}\/}\nolimits\!\left(\mathbf{z}\middle|\boldsymbol{{\Omega}% }\right)$ : scaled Riemann theta function, $\realpart{}$ : real part and $\boldsymbol{{\Omega}}$ : a Riemann matrix
Permalink:: http://dlmf.nist.gov/21.4.F2.mag
Encodings:: Magnified png, VRML, X3D, pdf