Hi guys, I am trying to plot the following functio as a vector field in 3D <pre>Piecewise[{{{(3*z*(1 - z^2/(x^2 + y^2 + z^2))*Log[ro/ri]*<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Sin[\[x, y, z]])/(4*Sqrt[x^2 + y^2 + z^2]), <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (3/4)*(1 - z^2/(x^2 + y^2 + z^2))^(3/2)*Log[ro/ri]*<br>&nbsp;&nbsp;&nbsp;&nbsp; Sin[\[x, y, z]], (3/4)*(1 - z^2/(x^2 + y^2 + z^2))*<br>&nbsp;&nbsp;&nbsp;&nbsp; Cos[\[x, y, z]]*Log[ro/ri]}, <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Sqrt[x^2 + y^2 + z^2] &lt; ri}, <br>&nbsp;&nbsp;&nbsp;&nbsp; {{(z*(-(z^2/(6*(x^2 + y^2 + z^2))) + (1 - <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; z^2/(x^2 + y^2 + z^2))*(-(5/12) - (1/8)*(1 + <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; ri^2/(x^2 + y^2 + z^2))*Cos[2*ArcTan[x, y]] + <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (3/4)*Log[ro/Sqrt[x^2 + y^2 + z^2]]))*<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Sin[\[x, y, z]])/Sqrt[x^2 + y^2 + z^2], <br>&nbsp;&nbsp;&nbsp; Sqrt[1 - z^2/(x^2 + y^2 + z^2)]*<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (-(z^2/(6*(x^2 + y^2 + z^2))) + (1 - <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; z^2/(x^2 + y^2 + z^2))*(-(5/12) - (1/8)*(1 + <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; ri^2/(x^2 + y^2 + z^2))*Cos[2*ArcTan[x, y]] + <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (3/4)*Log[ro/Sqrt[x^2 + y^2 + z^2]]))*<br>&nbsp;&nbsp;&nbsp;&nbsp; Sin[\[x, y, z]], <br>&nbsp;&nbsp;&nbsp; Cos[\[x, y, z]]*(-(z^2/(6*(x^2 + y^2 + z^2))) + <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (1 - <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; z^2/(x^2 + y^2 + z^2))*(-(5/12) - (1/8)*(1 + <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; ri^2/(x^2 + y^2 + z^2))*Cos[2*ArcTan[x, y]] + (3/4)*<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Log[ro/Sqrt[x^2 + y^2 + z^2]]))}, <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; ri &lt; Sqrt[x^2 + y^2 + z^2] &lt; ro}}, 0]</pre>Then I try to plot it using:<pre class="mcode_edit">vecs = VectorPlot3D[Bfield, {x, -4, 4}, {y, -4, 4}, {z, -4, 4}]</pre>But nothing comes out. I'm not sure why it is behaving this way. Any suggestions would be really appreciated. Thanks