It seems I'm having an incredibly difficult time communicating, here.Joseph Elfelt wrote:You might try looking at your file with Gmap4 displaying the Google aerial since you can zoom in a lot more than when looking at the topos.
With the aerial view displayed, zoom in all the way on any 'spike'.
Each noticeable bend in your track is a trackpoint your GPS recorded.
I think we can conclude that when zoomed in a bunch the Google map API does a more-or-less decent job of showing the data in your file on the screen, including the 'spike' data. But when not zoomed in a bunch, sometimes 'spike' data in a file is not shown correctly on the screen.
I'm curious if you zoom way in with Google Earth do the spikes look the same as with Gmap4?
I'm definitely not pointing fingers at you, Gmap4, or anything else! Just trying to share info I thought you'd find interesting.
As I said, I'm extremely familiar with the data. I've only viewed it in Google Earth, Garmin BaseCamp, TopoFusion, and a few other apps, but not Google Maps until now. I carried the devices that recorded it step by step. I've edited it, at the point level, to clean up odd reflections off canyon walls and such.
I've also been a Windows developer since 1990, and other platforms before that. I know the Windows GDI, and how those spikes occur in certain circumstances. It's a function of mitering sharp angles between line segments, when the line thickness is greater than the distance between sequential points. Most apps overcame this years ago, so I was taken a bit by surprise to see it in GM now.
No spikes in Google Earth (or other non-Google apps). It has a far better algorithm, apparently, for line rendering. I think I could pretty well eliminate them in GM if I were to recode the KML to use minimal line thickness. Haven't bothered trying that, yet. Zooming deeply in with GM does eliminate most of the spikes, to the extent that the linewidth becomes fewer pixels than the distance between points, yeah.
Ah well, I think I've hit that point of TMI? You offer a very cool tool, and I'm sorry I dragged this off into esoterica.