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Re: [OziUsers-L] Re: Perfomance with lots of maps

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  • Teppo Rapo
    One thing about skannig maps is that OE scans only MAP files, very small text files, it does nothing to do with images, or size of them as long as you dont
    Message 1 of 7 , Feb 1, 2002
      One thing about skannig maps is that OE scans only MAP files,
      very small text files, it does nothing to do with images, or size of them
      as long as you dont load them to screen.

      Teppo Rapo
      Helsinki/Finland
      N 60'15.636
      E025'01.861



      ----- Original Message -----
      From: "Geoff Greig" <geoffg@...>
      To: <OziUsers-L@yahoogroups.com>
      Sent: Friday, February 01, 2002 5:38 AM
      Subject: Re: [OziUsers-L] Re: Perfomance with lots of maps


      > Dafydd,
      >
      > This is what I did to test it.
      >
      > I loaded a map with Load Map file. This took 11 seconds because the map was
      > on a CD.
      >
      > I them used the Moving Map NMEA Simulator. Place the "Here" close to the
      > edge of the map and started moving map at 60 KPH.
      >
      > Ozi started by displaying Scanning maps on the status line. This took a
      > while, but I did not time it. When the pointer got to the edge of the map,
      > the next map loaded in about 2 seconds. I was not expecting it to be this
      > quick.
      >
      > I will do another test. Again only 2 seconds. This is less time than it
      > takes to scan for a new map or to load the image.
      >
      > One more test
      >
      > Again only about 2 seconds.
      >
      > I think Des must be doing some looking ahead hear. Perhaps storeing all the
      > surrounding maps in memory so not needing to read them from disk. Also
      > Windows must be doing some casheing of the CD drive.
      >
      > I will do another test on some maps that are a long way from the present
      > ones.
      >
      > Again 2 seconds
      >
      > Well I dont think you need to worry about your 900 od map load times.
      >
      > Geoff Greig
      > Brisbane Australia
      >
      >
      >
      >
      >
      > dafloz wrote:
      >
      > > Thanks for your help Geoff but one thing - is there also a 5-10
      > > second delay when using the moving map as your position moves from
      > > one map to the next -of the same size and scale with a neat border -
      > > i.e. no overlap?(ignoring load time of the actual map as the load
      > > times with the tiff's I've tested seem to be very quick).
      > >
      > > Thanks,
      > >
      > > Dafydd - UK
      > >
      > > --- In OziUsers-L@y..., Geoff Greig <geoffg@o...> wrote:
      > > > dafloz,
      > > >
      > > > Ther are two timing issues here.
      > > >
      > > > 1. The time it takes for Ozi to determine which map to load
      > > >
      > > > 2. The time it takes to load the map
      > > >
      > > > The first depends on how many map you have. The more Ozi map files
      > > it has to
      > > > look through the longer it takes.
      > > >
      > > > I have a direcory structure set up that has:
      > > >
      > > > Maps 100 maps
      > > >
      > > > Subdirectorys
      > > >
      > > > Auslig Maps 544 maps
      > > > New Zealand maps 19 maps
      > > > Vic 100K 127 maps
      > > > Vic 25k East 631 maps
      > > > Vic 25 West 1,118 maps
      > > >
      > > > So a total of 2,539 map files
      > > >
      > > > If I have a large map displayed and right click and select Find Map
      > > at Cursor
      > > > it takes Ozi between 5 and 10 Seconds to display a list of all the
      > > maps
      > > > aviable at that poistion.
      > > >
      > > > The 5 second varience depends on if a previous Find Map at cursor
      > > has been
      > > > done. If it has, a lot of what Ozi need to look at is still in
      > > Cache Memory.
      > > > Otherwise it had to be read from disk. I am ruinning a 1 GH
      > > processor and an
      > > > IBM 7200 RPM 30 GB hard drive.
      > > >
      > > > I should also point out that it only takes Ozi 3 seconds before it
      > > displays
      > > > the Maps Aviable for Cursor Position Dialog and the first map. The
      > > remaining
      > > > time is looking through the sub directories and readjusting the
      > > display
      > > > order.
      > > >
      > > > I could speed up the searching for maps by restricting the number
      > > of map
      > > > files Ozi has to look at. This can be simply done by moving around
      > > the
      > > > direcrory structure. eg. If I dont want to user the 100K maps I
      > > could move
      > > > then out side of the MAP directory so they would not be looked at
      > > at all.
      > > >
      > > > The second issue, the time it taked to display the map depends on
      > > the size of
      > > > the file to be loaded and the format it is stored in. I have 6.73
      > > MB .JPG
      > > > image that tha ttakes about one and a half minutes to load, yet
      > > that same
      > > > image takes 2 seconds to load in OZF2 format even though it is
      > > 10MB. Of
      > > > course the OZF2 format only loads part on the image into memory at
      > > a time.
      > > >
      > > > Re the icon that plots your position on the moving map. You can
      > > change to
      > > > one of the other 8 icons, change its color and size in the
      > > configuration
      > > > under the Moveing Map tab, but I cant see anyway of using your own
      > > icon. I
      > > > think they may be in the Ozi executable or a DLL as they dont
      > > appear to be
      > > > any of the ones in the Symbols directory off the Ozi installation
      > > directory.
      > > >
      > > > Geoff Greig
      > > > Brisbane Australia
      > > >
      > > > dafloz wrote:
      > > >
      > > > > Has anyone had any experience of using a very large number of
      > > tiled
      > > > > maps in OziExplorer (moving map) and how it affected performance?
      > > > >
      > > > > I am planning to try to use all the 1:50,000 maps of the UK which
      > > > > amounts to about 900 maps. The maps are about 10mb each (i.e.
      > > almost
      > > > > 10Gb of maps). I was just wondering about whether the tiling speed
      > > > > becomes an issue - does it take a lot longer when the software is
      > > > > constntly searching for the next tile or a more detailed map (this
      > > > > needs to be a quick response). They would all have to be in the
      > > same
      > > > > directory.
      > > > >
      > > > > Also, a lot less important, is there any way of customizing the
      > > icon
      > > > > that plots your position on the moving map?
      > > > >
      > > > >
      > > > > To unsubscribe from this group, send an email to:
      > > > > OziUsers-L-unsubscribe@e...
      > > > >
      > > > >
      > > > >
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      > > http://docs.yahoo.com/info/terms/
      > >
      > >
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      > >
      > >
      > >
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      >
      >
      >
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      >
      >
      >
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      >


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