Unsolved Model with large data from file
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So I would like to do something like :
QCache<int, MyItem > datas; model::data(QModelIndex index) { return datas[index.row()] }
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@dridk
Ok so binary or text format ?
3 GB of such lines. wow :)
must be many millions. -
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Im not sure cache will make you happy.
But yes something like that.But I worry about filling the cache.
as file seek into such file is expensive too.How big section of the data do u need to have loaded at any given time?
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@mrjj This the main difficulty ! The view is a painted widget ! Where you can zoom in/out, drag left and right !
Imagine a very large horizontal scrollable plot ! This is it ! So, that's mean, I have to fit the cache with the current view zoom level ! ... Looks difficults! -
Yes it sounds somewhat/very complex.
Normally plot widgets die around some millions plots.
Each "DNA" is that just a dot or does it have lines etc?Is this file u fool around with , available from
https://genome.ucsc.edu -
Briefly, the DNA is a string of 3 billions of A,C,G,T .
They are many extra data containing feature of dna. For exemple :
between positionA and positionB, they are a gene. Those features are saved into different file format , and always have this fields avaible : posA, posB, value1, value2...So, I want to make a genome browser, which show "track" aligned with DNA. It can have many track. For exemple, this picture is a genome browser showing :
https://www.youtube.com/watch?v=HnVrjj0RmOg
And this screenshot which show different tracks :
http://www.cureffi.org/wp-content/uploads/2013/03/ucsc-genome-browser-mapability-gc-percent-highlighted-1024x440.pngAll data are avaible from UCSC table browser :
https://genome-euro.ucsc.edu/cgi-bin/hgTables?hgsid=212129308_3BqNFprOMlddL1eZgG2seuarNOqp -
@dridk
Ok. thank you for the info.
I see what you try to make. Interesting.Since you are viewing a segment at a time, maybe a memory mapped file
approach is suitable?is the platform windows or linux?
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@mrjj Should be avaible everywhere. Why this question ?
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@dridk I see one segment at a time.. But I want to have the feeling that you can move smoothy without any load
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@dridk
well both platforms supports mem files.
I have not tried Qt version so was just to know.
I have used it on windows with native API to fool around in 23 GB image.But it seems Qt support this crossplatform.