Bryan Magee, The Philosophy of Schopenhauer (1997) has Ch.14 dedicated to: Schopenhauer's Influence on Wittgenstein.
[page 310] This influence can be asserted with absolute certainty; it is clear in the notebooks, and Wittgenstein himself stated in conversation that when he was young he believed Schopenhauer to have been fundamentally right [...].
This influence seems qalso present into 5.62-63, with the critique of solipsism:
5.6 The limits of my language mean the limits of my world.
5.62 This remark provides the key to the problem, how much truth there is in solipsism.
For what the solipsist means is quite correct; only it cannot be said, but makes itself manifest.
The world is my world: this is manifest in the fact that the limits of language (of that language which alone I understand) mean the limits of my world.
5.63 I am my world. (The microcosm.)
5.631 There is no such thing as the subject that thinks or entertains
If I wrote a book called The World as I found it, [...]
5.632 The subject does not belong to the world: rather, it is a limit of the world.
5.64 Here it can be seen that solipsism, when its implications are followed out strictly, coincides with pure realism.
6.373 The world is independent of my will.
with Schopenhauer's first sentence of The World as Will and Idea :
"The world is my idea".