Aww ... with that it's around 3ms now. Thanks :)
On Monday, June 15, 2015 at 7:34:36 PM UTC-5, Jason Wolfe wrote:
>
> Might also be something to do with this:
>
> https://github.com/Prismatic/hiphip#performance-know-your-options
>
>
>
> On Monday, June 15, 2015 at 3:27:59 PM UTC-7, Ritchie Cai wro
Might also be something to do with this:
https://github.com/Prismatic/hiphip#performance-know-your-options
On Monday, June 15, 2015 at 3:27:59 PM UTC-7, Ritchie Cai wrote:
>
> My java was 1.8.0_05-b13. Upgraded it. Now it's around 9ms, close enough.
>
> Thanks a lot.
>
> On Monday, June 15, 20
My java was 1.8.0_05-b13. Upgraded it. Now it's around 9ms, close enough.
Thanks a lot.
On Monday, June 15, 2015 at 4:59:57 PM UTC-5, Steven Yi wrote:
>
> I typed the array-max code and test in a REPL launched with "lein
> repl" in a terminal. I did do that in the root of one of my projects
>
I typed the array-max code and test in a REPL launched with "lein
repl" in a terminal. I did do that in the root of one of my projects
that had settings on to use 1.7.0 and to warn on reflection and
unchecked math. When I launched just now I have these versions
reported to the terminal:
REPL-y 0.3
Ha, you are right. That really make things a lot faster now. All three
different implementations now pretty much runs about the same speed, no one
is significantly faster or slower. Really appreciate your help.
However, what really puzzles me at this point is that array-max call
speed. On all
I'm not sure why you'd see much slower results there. For reference,
I'm on a Core i7-2720-M (MacbookPro 8,1 13" early 2011), and was using
clojure-1.7-beta3.
Also, I looked at the code you posted and I'm not so sure about your
assumption that Java arrays are slower:
* in load-txt-image_array, y
Unfortunately, I don't get to decide the data format. It's a dump from
previous stage. Also, it's supposed to be super easy for Physics people to
look at. If you every work with them, you'll know what I mean XD.
But thanks for the suggestion.
On Thursday, June 11, 2015 at 7:30:07 AM UTC-5, Andy
On Thursday, June 11, 2015 at 5:32:02 AM UTC-4, Ritchie Cai wrote:
>
> Just wondering though, is there a faster way to load an array than this
> way?
> https://github.com/malloc82/imaging/blob/45475b99f564b1ac77e668e04b91cb9c01a096d7/src/imaging/dicom.clj#L138
> the data file I'm trying to read f
> Lesson learned here for me is that only use java array when absolutely
> necessary. I always thought since it's primitive array, it should be the
> fastest. Apparently not!
This bears repeating. I often find it hit-and-miss to know when idiomatic
Clojure will be faster than turning to Java. Ar
Yup. Reflection is issue, I needed type hint.
However, on another note, I notice that in your first test case, your
evaluation takes about 3 ms, but on my machine it takes 76 ms. I'm running
a Xeon CPU at 3.5 GHZ, clojure-1.7-RC1. What could cause such a huge
different timing?
Thanks.
On Wedn
I tried with vectorz here:
https://github.com/malloc82/imaging/blob/45475b99f564b1ac77e668e04b91cb9c01a096d7/src/imaging/dicom.clj#L130-L161
and I'm really impressed with it's performance.
The performance is shown here:
imaging.dicom> (def data3 (timer "total: " (load-txt-image_matrix
"resourc
Yup. As it turns out, the slow down is pretty much due to reflection. After
added type hint, it's much better now.
The code can be viewed here:
https://github.com/malloc82/imaging/blob/45475b99f564b1ac77e668e04b91cb9c01a096d7/src/imaging/dicom.clj#L46-L161
They are three different implementation
As mentioned by Colin and Andy, I would guess it would be some form of
boxing and reflection going on. I tried the following:
(defn array-max [^doubles arr]
(let [len (alength arr)]
(loop [m Double/NEGATIVE_INFINITY indx 0]
(if (< indx len)
(recur (max m (aget arr indx))
Consider using core.matrix with vectorz-clj for operations on large
numerical arrays / vectors of doubles. It is a *lot* faster than using
Clojure vectors for this kind of scenario, plus it has a lot of helpful
array operations already defined.
(use 'clojure.core.matrix)
(def v (array :vectorz
Will guess in the dark but would boxing come into play here?
> On 10 Jun 2015, at 21:03, Ritchie Cai wrote:
>
> I'm working on a java array of double with 128 elements. I need the max
> and min values of the array. So I initially tried areduce and loop, both
> gives runs around 20 seconds.
Add this line at the top of your file where you try areduce and loop, and
look for any reflection warnings that occur when loading the file:
(set! *warn-on-reflection* true)
If there are none, probably best to post a link to your code, or paste it
in a message here if it is short enough, so other
I'm working on a java array of double with 128 elements. I need the max
and min values of the array. So I initially tried areduce and loop, both
gives runs around 20 seconds. But when try (apply max (vec array)) I get
result under 90 ms.
Can anyone explain why there is such a big difference?
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