Abstract: Methods, non-transitory machine-readable mediums, and system to provide location services are described. In an embodiment, a method provides receiving at least two position fixes for a trajectory of an electronic device, where the at least two position fixes are obtained intermittently, matching the at least two position fixes to points on a path indicated in map data, and computing a distance for the trajectory using distance information using the map data.

Abstract: A method for calibrating a magnetometer of an electronic device can include detecting a change in a magnetism of the electronic device, collecting a first magnetic field data from the magnetometer at sampling frequency of at least 1 hertz, generating an elliptical calibration model based at least partially on the collected first magnetic field data, collecting a second magnetic field data from the magnetometer, and fitting the collected second magnetic field data to a sphere using the elliptical calibration model.

Abstract: A system and method for collecting motion data using a fitness tracking device located on an arm of a user, detecting that the arm is constrained based on the motion data, estimating a stride length of the user based on the motion data and historical step cadence-to-stride length data, calculating fitness data using the estimated stride length, and outputting the fitness data to the user.

Abstract: Disclosed embodiments include wearable devices and techniques for detecting walking workouts. By accurately and promptly detecting the start of walking workouts activities and automatically distinguishing between walking workout and causal walking activities, the disclosure enables wearable devices to accurately calculate user performance information when users forget to start and/or stop recording walking workouts.

Abstract: Disclosed embodiments include wearable devices and techniques for detecting the end of hiking activities. By accurately and promptly detecting the end of hiking activities automatically, the disclosure enables wearable devices to accurately calculate user performance information when users forget to start and/or stop recording a hiking activity.

Abstract: A method for calibrating a magnetometer of an electronic device can include detecting a change in a magnetism of the electronic device, collecting a first magnetic field data from the magnetometer at sampling frequency of at least 1 hertz, generating an elliptical calibration model based at least partially on the collected first magnetic field data, collecting a second magnetic field data from the magnetometer, and fitting the collected second magnetic field data to a sphere using the elliptical calibration model.

Abstract: Disclosed embodiments include wearable devices and techniques for detecting cycling activities and monitoring performance during cycling. By accurately and promptly detecting the end of cycling workouts automatically, the disclosure enables wearable devices to accurately calculate user performance information when users forget to stop recording a cycling activity session. In various embodiments, cycling activity detection techniques involve a cycling speed measure that incorporates terrain gradient determined based on pressure data. In various embodiments, the cycling activity detection techniques may distinguish between a temporary stop and an intentional stop using an estimated energy expenditure.

Abstract: Aspects of the subject technology relate to electronic devices with pressure sensors. Pressure sensor occlusion may be detected based on a comparison of a variance of pressure data from the pressure sensor with a variance of acceleration data from an accelerometer of the device. If a ratio of the pressure data variance to the acceleration data variance is above a threshold, occlusion may be identified. Data from other sensors in the device or in an external device, or other features of the pressure data, may be used to identify a type of occlusion.

Abstract: Aspects of the subject technology relate to electronic devices with pressure sensors. Pressure sensor occlusion may be detected based on a comparison of a variance of pressure data from the pressure sensor with a variance of acceleration data from an accelerometer of the device. If a ratio of the pressure data variance to the acceleration data variance is above a threshold, occlusion may be identified. Data from other sensors in the device or in an external device, or other features of the pressure data, may be used to identify a type of occlusion.

Abstract: A system and method for collecting motion data using a fitness tracking device located on an arm of a user, detecting that the arm is constrained based on the motion data, estimating a stride length of the user based on the motion data and historical step cadence-to-stride length data, calculating fitness data using the estimated stride length, and outputting the fitness data to the user.