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[HOWTO] How to fix Laps with bad data points

Posted: Sun May 18, 2014 4:34 pm
by cannon1000
I have a lap that has some bad data points way off line. I have tried unsuccessfully to delete or fix them. Is there a better way? The goal is to use Circuit Tools for lap analysis and clean up video/data overlays.

Data File is here: https://dl.dropboxusercontent.com/u/571 ... 936.hlptrl

Re: How to fix Laps with bad data points

Posted: Sun May 18, 2014 5:59 pm
by Harry
Here is a how-to:
  • Export exactly the lap showing issues to .hlptrl (the above file shows a full day laps - which makes it difficult to find the bad fixes). Send the export to yourself to edit it.
  • In case it arrives as a .hlptrz file it is compressed and needs to be uncompressed: rename it to .hlptrl.gz and use your favorite unpacker to uncompress it.
  • Check the lap for the problem you are looking for. Looking into your sample, it seems there are two fixes with very bad accuracy (red dots when GPS fixes are displayed in LapTimer's Data Recording area and large blue bubbles for the accuracy.
  • Open the .hlptrl file using either TextWrangler on MacOSX or Notepad++ on Windows.
  • Search for the problem (bad accuracy in our case) and remove the faulty fixes:

Code: Select all

			<fix index="57615">
				<date>04-MAY-14,20:52:50.21</date>
				<coordinate>34.149914,-83.811872,283.0</coordinate>
				<speed>0.0</speed>
				<positioning>0,2</positioning>
				<satellites>0</satellites>
				<direction>265.4</direction>
				<hdop>0.00</hdop>
				<accuracy>9497.4</accuracy>
				<relativeToStart>1424.3,00:24.26</relativeToStart>
				<acceleration>
					<source>1</source>
					<lateral>-0.81</lateral>
					<lineal>0.39</lineal>
					<coordinate>34.150277,-83.811907</coordinate>
				</acceleration>
			</fix>
			<fix index="57616">
				<date>04-MAY-14,20:52:50.28</date>
				<coordinate>34.149539,-83.811181,283.0</coordinate>
				<speed>0.0</speed>
				<positioning>0,2</positioning>
				<satellites>0</satellites>
				<direction>265.4</direction>
				<hdop>0.00</hdop>
				<accuracy>9497.4</accuracy>
				<relativeToStart>1500.2,00:24.33</relativeToStart>
				<acceleration>
					<source>1</source>
					<lateral>-0.84</lateral>
					<lineal>0.32</lineal>
					<coordinate>34.149915,-83.811218</coordinate>
				</acceleration>
			</fix>
  • Once the faulty fixes are removed, save the file and send it to any email account you can access on your smartphone.
  • Long press the attachment in the mail app and select LapTimer to import it.
  • Once this is done, you will find an additional lap (same date / time) without the problem fixes; remove the faulty one.
- Harry

Re: [FAQ] How to fix Laps with bad data points

Posted: Wed May 21, 2014 2:24 am
by cannon1000
Many thanks! Much easier than trying to fix via the CSV file!!

Re: [FAQ] How to fix Laps with bad data points

Posted: Thu May 22, 2014 2:53 pm
by gplracerx
If the rest of the data, like OBD, for the fix is ok, you could interpolate the latitude and longitude and other GPS data from the good fixes before and after rather than throw out the whole fix. This procedure should also work for bad OBD data.