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This project implements a single web page that can parse, analyze, split, and edit activity files in GPX, TCX, and FIT file formats.
Typically these files would be generated by a workout tracker, such as a smart watch or a bicycle computer. You may also be able to export data in one or more of these formats from a cloud service such as Strava or Garmin Connect.
GPX (GPX eXchange) is an XML-based file format for describing tracks (i.e. GPS points recorded during an activity) and routes (location information that is not specific to an activity).
TCX (Garmin Training XML) is an XML-based file format. It is slightly more complicated than the GPX format with support for multiple activities. It also has native support for heart rate, cycling power, and cadence information.
FIT (Flexible and Interoperable Data Transfer) is a binary file format and is commonly used to record data on fitness tracking devices, such as smart watches and bike computers.
Though FIT files can often be downloaded from a vendor's cloud service (i.e. Garmin Connect), they can often be found by connecting the device directly to your computer. Some devices (i.e. Coros and Wahoo watches and bike computers) come with companion phone apps that allow to export an activity's FIT file directly to a cloud file service, such as Dropbox or the iCloud Drive.
FIT files have the potential to contain much more information that either GPX or TCX files. In addition things that are typically expected, such as location data, heart rate, and cycling power/cadence, FIT files can contain information from various other devices, such as electronic shifters, radar units, and glucose monitors.
Select a single file of a supported file type and click the Analyze File(s) button.
On a mobile platform, such as iOS, choose the Browse option and select one or more files. On iOS, you will be able to select files from the iCloud Drive.
To compare files, just select multiple files and click the Analyze File(s) button. A summary of each file will be displayed followed by graphs comparing power, heart rate, etc. Finally a map will show each track.
Data can be exported in either GPX or TCX format. A FIT file exporter has not been developed (yet).
The Export button will be displayed near the top of the screen after file analysis is complete.
An example of when you might want to split a file is if you have a file containing multiple activities, for example, recording an entire triathlon as a single run.
You may also want to split a file if it starts or ends with a large amount of junk, such as when you forget to stop a device after crossing the finish line, etc. In other words, splitting a file is another to trim an activity, just throw away the file containing the unwanted portion.
A split option will be displayed along with the Export button after file analysis is complete. When choosing to split a file for export, two links will be generated and appended to the page. You must click these links to download the files, due to browser security limitations.
If you analyze multiple files, a Merge button will replace the usual Export button. Pressing the Merge button will export a file that contains the concatenation of each file. Data with the same timestamp will be averaged together (i.e., two different heart rate measurements taken at the same time, from different devices, will be averaged together in the merged file).
The page is a combination of HTML, Javascript, CSS, and WebAssembly compiled from Rust. It runs entirely in the local web browser and does not transmit anything about the file(s) being analyzed.