GPS elevation graphs

This blog post is a short history on the evolution of GPS elevation graphs on trackprofiler.

When starting the service I created a simple javascript based graph library and used it for GPS tracks elevation graphs:

...but over time, some problems arose. First of all it was slow and rendered in the browser. That means that for slower computers the graphs slowed the rendering of the entire page by more than a second.

And, there was another thing I wanted to show on the graph -- the speed graph. So, a month ago a new version of TrackProfiler was deployed. The graph is now a PNG image created on the server -- no client's CPU is used. The graph, then, looked like:

The green graph is speed, the gray one is elevation.

But, there still was one thing in the evolution of the graph I wanted to make. For example on the GPS track shown -- it started on elevation 197m and never went below. So, it don't make sense to show the vertical  part of the graph from zero. It only makes the uphill and downhill slopes flatter.

After another iteration (online for the last 3 days) -- the vertical part of the graph now starts from the minimum elevation found on the graph. And the uphill/downhill slopes are better visible:

See an example here, or try it yourself on TrackProfiler.

Gpxpy version 0.8.0

Gpxpy is an open source python library for parsing and manipulating GPX files. It is one of the core parts of the TrackProfiler web site, and one of the open sourced parts of it. In the last few months a lot of work is done. Two new important features:

• gpxpy can now use lxml (if available) to parse GPX files (contribution from Isaev Igor)
• Python 3 support (contribution from Robert Smallshire)

...and many more small bug fixes and unit tests to make it faster and more stable.

It is licensed under Apache 2.0 and there should be no problems using it even with your own closed-source commercial apps.

PS. The original trackprofiler utility app and the library used to show analytics graphs (cartesius) are also open source.

Even more GPS editing tools

Even more GPS editing tools are available in the newest version of TrackProfiler. Those are:

• Remove time metadata from the track,
• Remove elevation metadata from the track,
• Elevation graphs are not shown if the track has no elevation data,
• Move graphs,
• Add/remove to elevation.

Plus, few bug fixes:

• Problem with embeding tracks whose subject contain non-ASCII characters,
• Default background for embeded tracks,
• Better handling for inbound emails for email track uploading.

Enjoy!

Track page load speed

Just rolled out a new update with a an important improvement. The problem was that the track page was generated entirely at the moment you requested it (i.e. you clicked on the link). This is a somewhat slowish process and consequently the page load speed was also slow.

Now parts of the page are cached and the page load speed is improved by 3-4 times.

Enjoy!

Embeding tracks

This month -- embeding GPS tracks from Trackprofiler in your site. It's easy -- when on the page with your track, just click the "Embed" tab. Then, copy the code on your page. There are 3 predefined widths for widgets, select the one that best fits in your page.

Here is an example of how it looks:

Export track stats to a CSV file

In the last two weeks I was hiking around my small city (Višnjan). I made a total of 737.96564616 meters uphill, 32575.07452042m long (32680.59386254m if counting elevation).

How do I know those numbers?

Because there is a new option in TrackProfiler -- You can export track statistics in a CSV file. For all files or for files with specific tags. All I did was to export in CSV files with tags "visnjan" and "hiking" and then computing the sum of columns with Excel.

If you tag all your hiking tracks with "hiking", tracks when you were in Italia with "italy" and Alps tracks with "alps" -- just enter "hiking italy alps" in the new CSV exporter form. The resulting file will contain data for all those tracks.

Track analytics graphs

With a new version -- one new feature. Graphs for every track uploaded. At the moment, there are three kind of graphs:

• Graph with elevation and speed,
• Uphill/downhill ratio,
• Elevation and steepness heatmap.

I'll probably add more in the future.

PS. The library used or generating the graphs is now open source: see cartesius on github. 

New layout (final)

The new layout (based on twitter bootstrap) is out.

Redesign

I'm preparing a complete redesign of the site. Here's how it looks now:

...and here how it will look in a few days:

Online GPS Route Editor [screencast]

What's the difference between "GPS Route" and "GPS Track"?

• A track is a collection of points of a path you actually made in real life. Track points contain GPS coordinates, time when it is recorder, the elevation of the point, ...
• A route is a collection of points of a path you didn't made in real lif, but plan to. Route points don't contain elevation and time. Routes usually contain less points than tracks but may be helpful when you organize your future outdoor activities.

Now, Trackprofiler has a new option to create, edit and organize routes. You can see here a quick screencast on how it works: