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Everything posted by ShaunR
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OK. I'm fairly happy with the performance of the API (there are to be a couple more minor tweaks but nothing drastic). So I started to look at SQLites performance. In particular I was interested in how SQLite copes with various numbers of records and whether there is deterioration in performance with increasing numbers of records. Wish I hadn't Below is a graph of inserts and select queries for 1 to 1,000,000 records. The test machine is a Core 2 duo running Win 7 x64 using Labview 9 SP1 x32. Each data point is an average over 10 bulk inserts using the "Speed Example.vi". The database file was also deleted before each insert to ensure fragmentation and/or tree searching were not affecting the results. I think you can see that both inserts and select times are fairly linear in relation to the number. And (IMHO) 5 seconds to read or write a million records (consisting of 2 columns) is pretty nippy Now the same machine (exactly the same test harness) but using LV2009 SP1 x64 Hmmm. It's interesting to note. that up until about 100,000; x64 it performs similarly to x32. However, memory usage reported by the windows task manager above 200,000+ shows x64 starts to climb further. Typically by the end of the test x32 has consumed about 450MB whilst x64 is about 850MB when viewed in the windows task manager. Checking SQLites internal memory allocation using the "Memory.VI" yields an identical usage between both tests. However,. LV x64 seems to be using 2x windows memory. I'm tempted to hypothesise that it is memory allocation in LV x64 which is the cause. Can anyone else reproduce this result? A single check at (say) 500,000 should be sufficient.
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LV 2010 Icon Editor bug affects sub vi performance
ShaunR replied to Daklu's topic in LabVIEW General
Reproduced also in LV2009 x32 & x64 (PDS) as well as LV2009 x64 & x32 (PDS) I also noticed that if you run it before saving (i.e. have modified VI's in memory because I switched from LV x32 to x64) you get the same results. If you then "Save all" it runs ok. However, after invoking the Icon Editor, "Save All" or a re-compile has no effect. -
You smooth talker
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You need to pass the "reference" of the control to the sub VI. By wiring the graph control you are only passing the "data" that the graph contains,
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http://www.metacafe.com/watch/1154898/how_to_make_a_tinfoil_hat/ I wonder what colour the sky is on her planet
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That's fantastic Just goes to show. "There are no bad programs, only bad programmers". I think I'll set that up as my wallpaper....move over Grace Park
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Take a look at the speed example.
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You do not need to explicitly open or create a file with the any of the high level API (the exception being "Query by ref") as it will open or create a file if one doesn't exist. Just specify the fie name. You cannot write directly to the file using standard file write functions. A SQLite file has a complex structure.
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Color Change with value in tank... or something...
ShaunR replied to 335_x's topic in LabVIEW General
I don't think I'm that bad -
Be careful whose toes you step on today because they might be connected to the foot that kicks your ass tomorrow!
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Color Change with value in tank... or something...
ShaunR replied to 335_x's topic in LabVIEW General
In the "Dialog & User interface" palette the is a "Colorbox constant". You can wire that to it and choose a colour by clicking on it which will show the colour chooser dialogue. -
Sweet
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There's probably a better mathematical solution, but this works as a practical approximation for this sort of thing (certainly for repeatability at least). As Yair said. Take loads of readings. Then calculate the mean and variance of your data. Plug those value into the probably density function for a truncated normal distribution and solve of X (note that b in this case is infinity). It is flawed in that it assumes your data is normally distributed (which it isn't its 1/2 of a normal distribution). But it will give a much better approximation.
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You could have just used the "Query.vi" and put in "SELECT DISTINCT Col1,Col2,Col3 FROM TableName;" then you wouldn't need to filter the results.
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Yup. I had a similar experience. At my old firm IT insisted that the had to install everything. I gave them a list of Labview and all the packages I needed and went and played with some instruments. After an hour they called me back to say it was complete. Great Where are the toolkits/packages? Umm. how do you install them (they said). So I showed them. After a few hours of sitting watching the install and drinking copious amounts of coffee the IT uy said "OK I'm off home". I said "When you come in tomorrow you need to phone NI and get all the activation codes (license was in ITs name). See you tomorrow so we can activate them all. Oh and by the way, we need to do this all again forl 8.2, 7.1 and 6.0 Can we do that the day after?" Next morning I had local admin rights and they transferred the license into my name
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SQLite API Version 1.2 released.
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Indeed.You will still have plenty of time to learn Russian so you can read it
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I hope your machine is networked to the internet. Mine isn't and after an install I have to hand type in 23 activation codes It's all got a bit ridiculous
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SQLite shows a download size of 4.8 MB. But the latest upload is only 1.8 MB. It looks like its the sum of all the versions. Is that right? The download page is geared towards showing information about a particular version (file name, version number, page title etc). Shouldn't it only show the size and download speed of the latest version?
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If you are using Version 1.1, then you can use the "Transaction Query.vi" as JCarmody referenced. If you are using version 1.2 (just uploaded so unlikely ) then you can use the "Insert Table.vi" or "Transaction Query.vi". Well. I cannot replicate your test because you haven't released the VIs. But I ran the speed test inserting 1,000,000 rows with version 1.2 and reset the PC. After 12 resets the DB was fine although Labview forgot all its palette settings on the 3rd reset . At that point I got bored since it takes about 1 minute for my PC to boot
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SMS has been the greatest assault on the English language since, erm "American English" The number of Thai people that think "before" is actually spelt "b4" is amazing.
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Yup. Still trying to get my head around all the compiler options (haven't even looked at linker stuff yet). Some compile, some don't. I've got them all installed I'm trying to compile against 10.4, 10.5, 10.6. Sometimes they won't compile at all depending on certain settings. I need to be able to figure out the minimum version since I won't have the luxury of just getting it to work on my system alone (looks like I'll have to install a few more Mac versions) Indeed. I'm in two minds about this. I would like to compile from source. But at the moment the debug is 5MB and a release is 2.4MB Xcode is not very intuitive and as soon as I figure out how and what it's doing..... will ditch it in favour of something else. In theory, we shouldn't need it at all since the Mac version of SQLite has all the scripts etc to build and install it.But I don't know what half the files are for (yet). It's a steep learning curve having never used a Mac before (just finding stuff takes me 1/2 an hour...lol). But getting there
