[script optimization challenge] Multi dimensional array filtering

Brian Yennie briany at qldlearning.com
Wed Aug 5 13:20:05 EDT 2009


Malte,

Beyond the ideas already presented, the only thing I can think of -  
and this would be a bit of work - is that if there are particular  
fields you know you will want to filter on, you could maintain a  
*sorted* copy of dgdata. For example, if you had a copy of dgdata  
sorted by name, you could filter on name very quickly using a binary  
search.

> Hey all,
>
> I just try to implement a life search on a datagrid. I was doing  
> this with the dgtext property. However this turns out to be too slow  
> on elder machines if there are many records (30k +) Now I am trying  
> to instead of setting the dgtext, to work with the dgdata. This  
> could speed up the whole process quite a lot, as the data would not  
> need to be turned into an array again by the data grid. Problem:  
> arrays can not be filtered. So what I would like to do is find the  
> quickest script that simulates array filtering in n dimensions if at  
> any rate possible. My clumsy first try looks like this. This only  
> "filters" the second level yet, so turning this into a function for  
> n-levels deep would be ideal. :)
>
> on mouseUp
>  local testarray,tprocess,test
>  repeat with i=1 to 30000
>     put any item of "meier,müller,john,doe" into testarray[i]["name"]
>  end repeat
>  answer the number of lines of the keys of testarray
>  put the millisecs into test
>  put the keys of testarray into tprocess
>  repeat for each line theLine in tprocess
>     if testarray[theline]["name"]="john" then
>        delete variable testarray[theline]
>     end if
>  end repeat
>  answer the number of lines of the keys of testarray&cr&the  
> millisecs-test
> end mouseUp
>
> This runs in 31 ms on my machine (Intel MacBook first gen, 2.16  
> GHz). I would like to have this quicker if possible. Also I´d like  
> the runtime on your machines, especially Macs pre Intel era.
>
> Any thoughts highly appreciated.
>
> All the best,
>
> Malte



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