This may not be the right forum to ask this question, but suppose that I have a multi-dimensional function $L$, and I want to compute its gradient w.r.t. a set of parameters $\theta$, where $[|\theta| > 1]$. I saw in several texts that they write it down as:
$$ \nabla_{\theta}L $$
However, $\nabla_{\theta}L$ occupies too much page width, i.e. if $\theta$ includes other qualifications such as $\theta_{i,t}$. Since am writing using a two column paper format, I want to conserve on text width, but I can take up more spaces height-wise. Is it correct to write the gradient this way?
$$ \frac{\nabla_{L}}{\nabla{\theta}} $$
or does it make sense if I stick to using partial derivative notations, i.e.
$$ \frac{\partial{L}}{\partial{\theta}} $$
You write it as $$\frac{\partial L}{\partial \theta},$$ because that's what the $\theta$ component of the gradient means, by definition.