# Fast 4D argmax

**URL:** https://discourse.julialang.org/t/fast-4d-argmax/58566
**Category:** Performance
**Tags:** tullio
**Created:** [April 4, 2021, 6:10pm UTC](https://discourse.julialang.org/t/fast-4d-argmax/58566 "2021-04-04T18:10:27Z")
**Posts on this page:** 1
**Showing post:** 23

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### Author: ![Non-Contradiction](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/non-contradiction/32/2208_2.png) [@Non-Contradiction](https://discourse.julialang.org/u/Non-Contradiction)
#### Post date: [April 5, 2021, 6:44pm UTC](https://discourse.julialang.org/t/fast-4d-argmax/58566/23 "2021-04-05T18:44:31Z")

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The performance here is indeed dominated by array transformation. Typically, the time can be decomposed into three parts.

1. JuliaCall interface function time cost (`julia_call` on the order of 10 microsends, `julia_command` on the order of 100 microseconds).
2. data transfer time cost, which will be on the order of milliseconds for a large data set like this.
3. julia function time cost.

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