[log, timestamp]
= magfieldlog(m)
returns the magnetic field log, where m is the name of
the mobiledev object that acquires the sensor data,
log is an m-by-3 matrix containing
magnetic field data points, and timestamp is an
m-by-1 vector of timestamps.
Get Logged Magnetic Field Data from Apple iOS Sensor
This example assumes that you have already installed
and set up MATLAB®
Mobile™ on your iOS device and connected it to your computer
running MATLAB. If you have not, see Install MATLAB Mobile on Your Apple iOS Device.
Start MATLAB
Mobile on your iOS device.
On the Sensors screen, tap the
Magnetic Field sensor.
Place the device where you want to get the sensor data.
On your computer, create a mobiledev object,
m, in MATLAB.
m = mobiledev
Begin logging data by enabling the Logging
property.
m.Logging = 1
This action starts the transmitting of data from all selected
sensors. You can also start transmission by tapping the
Start button in MATLAB
Mobile.
Get the logged magnetic field data.
[mf, t] = magfieldlog(m)
This returns the magnetic field log, where mf
contains the three data points in X,
Y, and Z coordinates, in
microtesla.
See Device Orientation for a diagram showing the X,
Y, and Z axes relative to
the device.
log — Name of variable for magnetic field log data m-by-3 matrix
Name of variable for magnetic field log data, returned as an
m-by-3 matrix of data points from the
Magnetic Field sensor on the iOS device. The three data points are
the magnetic field reading in X,
Y, and Z coordinates, in
microtesla.
Magnetic field is defined in relation to the X,
Y and Z axes. If you place
the device face-up on a table, the positive X-axis extends out of
the right side of the device, positive Y-axis extends out of the top
side, and the positive Z-axis extends out of the front face of the
device. This is independent of the orientation of the device.
timestamp — Name of variable for timestamp m-by-1 vector
Name of variable for timestamp, returned as an
m-by-1 vector of timestamps from the Magnetic
Field sensor on the iOS device. Time is in seconds, relative to the
InitialTimestamp property.
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