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Count samples within time bins for a set of sensors

Source: R/plot_sampling_effort.R
bin_samples.Rd

Summarize sensor sampling regimes for a set of imu or timestamp vectors by counting samples within fixed time bins. This produces the data that is used by plot_sampling_effort(), exposed for custom plots.

Usage

bin_samples(..., ids = NULL, bin_width = NULL, from = NULL, to = NULL)

Arguments

...

Any number of imu or timestamp vectors. All vectors must be the same length. Timestamps can be in POSIXct, POSIXlt, Date, or a number of seconds since 1970-01-01 00:00:00 UTC. Date objects are treated as being recorded at midnight, UTC.

ids

Vector of IDs used to group the observations in .... All observations for each group will be included in a single panel. Must be the same length as each of the vectors in ....

bin_width

Width of the time bins within which samples are counted. Provided as a units object, a difftime object, or a numeric value which will be interpreted as seconds. By default, the time range of the plot is divided into roughly 300 bins.

Decrease the bin_width to increase plot resolution, at the expense of legibility for sparsely collected data.

from, to

Start and end timestamps defining the range within which samples will be counted. Accepts the same formats as timestamps in .... By default, the full temporal extent of the data is used.

Value

A data frame with one row per non-empty lane, id, and bin, containing the following columns:

  • lane: The source vector in ..., labeled with that argument's name or expression. Each lane is drawn as one row by plot_sampling_effort().

  • id: Grouping identifier, as a factor. Absent when ids is NULL.

  • time: Bin start, in the timezone of the first lane.

  • n: Samples recorded in the bin.

  • rate: Effective sampling rate, n / bin_width, in Hz.

  • effort: rate as a fraction of the highest rate in the same lane, taken across all values of ids.

The bin width in seconds is attached as the "bin_width" attribute.

Details

Sampling effort is calculated by

  1. splitting the plotted time range into equal-width bins. The binned grid starts at from if provided. Otherwise, it starts at the closest multiple of bin_width at or before the first sample.

  2. counting the number of samples each sensor recorded in each bin, separately for every track.

  3. dividing each count by the bin width, giving an effective sampling rate in Hz.

  4. normalizing those rates within each lane, so that each lane's sampling effort values are relative to the maximum sampling effort in that lane, across all values of ids.

See also

plot_sampling_effort() to plot the output of bin_samples()

Examples

alb <- albatrosses()

bin_samples(acc = as_acc(alb), ids = move2::mt_track_id(alb))
#>    lane            id                time  n      rate     effort
#> 1   acc 4266-84831108 2008-07-27 00:00:51 38 3.1686030 0.65517241
#> 2   acc 4266-84831108 2008-07-27 00:01:03 22 1.8344544 0.37931034
#> 3   acc 4266-84831108 2008-07-27 00:14:51 16 1.3341486 0.27586207
#> 4   acc 4266-84831108 2008-07-27 00:15:03 44 3.6689088 0.75862069
#> 5   acc 4266-84831108 2008-07-27 00:29:50 13 1.0839958 0.22413793
#> 6   acc 4266-84831108 2008-07-27 00:30:02 47 3.9190616 0.81034483
#> 7   acc 4266-84831108 2008-07-27 00:44:49 10 0.8338429 0.17241379
#> 8   acc 4266-84831108 2008-07-27 00:45:01 50 4.1692145 0.86206897
#> 9   acc 4266-84831108 2008-07-27 00:59:49  7 0.5836900 0.12068966
#> 10  acc 4266-84831108 2008-07-27 01:00:01 53 4.4193674 0.91379310
#> 11  acc     4261-2228 2008-07-27 00:00:03  3 0.2501529 0.05172414
#> 12  acc     4261-2228 2008-07-27 00:00:15 57 4.7529046 0.98275862
#> 13  acc     4261-2228 2008-07-27 00:14:51 16 1.3341486 0.27586207
#> 14  acc     4261-2228 2008-07-27 00:15:03 44 3.6689088 0.75862069
#> 15  acc     4261-2228 2008-07-27 00:29:50 13 1.0839958 0.22413793
#> 16  acc     4261-2228 2008-07-27 00:30:02 47 3.9190616 0.81034483
#> 17  acc     4261-2228 2008-07-27 00:44:49 10 0.8338429 0.17241379
#> 18  acc     4261-2228 2008-07-27 00:45:01 50 4.1692145 0.86206897
#> 19  acc     4261-2228 2008-07-27 00:59:49  7 0.5836900 0.12068966
#> 20  acc     4261-2228 2008-07-27 01:00:01 53 4.4193674 0.91379310
#> 21  acc     2131-2131 2008-07-27 00:00:51 43 3.5855245 0.74137931
#> 22  acc     2131-2131 2008-07-27 00:01:03 17 1.4175329 0.29310345
#> 23  acc     2131-2131 2008-07-27 00:14:51 16 1.3341486 0.27586207
#> 24  acc     2131-2131 2008-07-27 00:15:03 44 3.6689088 0.75862069
#> 25  acc     2131-2131 2008-07-27 00:29:50 13 1.0839958 0.22413793
#> 26  acc     2131-2131 2008-07-27 00:30:02 47 3.9190616 0.81034483
#> 27  acc     2131-2131 2008-07-27 00:44:49 10 0.8338429 0.17241379
#> 28  acc     2131-2131 2008-07-27 00:45:01 50 4.1692145 0.86206897
#> 29  acc     2131-2131 2008-07-27 00:59:49  7 0.5836900 0.12068966
#> 30  acc     2131-2131 2008-07-27 01:00:01 53 4.4193674 0.91379310
#> 31  acc     1163-1163 2008-07-27 00:00:39  8 0.6670743 0.13793103
#> 32  acc     1163-1163 2008-07-27 00:00:51 52 4.3359831 0.89655172
#> 33  acc     1163-1163 2008-07-27 00:14:51 16 1.3341486 0.27586207
#> 34  acc     1163-1163 2008-07-27 00:15:03 44 3.6689088 0.75862069
#> 35  acc     1163-1163 2008-07-27 00:30:02 58 4.8362888 1.00000000
#> 36  acc     1163-1163 2008-07-27 00:30:14  2 0.1667686 0.03448276
#> 37  acc     1163-1163 2008-07-27 00:44:49 10 0.8338429 0.17241379
#> 38  acc     1163-1163 2008-07-27 00:45:01 50 4.1692145 0.86206897
#> 39  acc     1163-1163 2008-07-27 00:59:49  7 0.5836900 0.12068966
#> 40  acc     1163-1163 2008-07-27 01:00:01 53 4.4193674 0.91379310
#> 41  acc    3275-30662 2008-07-27 00:00:39 43 3.5855245 0.74137931
#> 42  acc    3275-30662 2008-07-27 00:00:51 17 1.4175329 0.29310345
#> 43  acc    3275-30662 2008-07-27 00:14:51 16 1.3341486 0.27586207
#> 44  acc    3275-30662 2008-07-27 00:15:03 44 3.6689088 0.75862069
#> 45  acc    3275-30662 2008-07-27 00:29:50 13 1.0839958 0.22413793
#> 46  acc    3275-30662 2008-07-27 00:30:02 47 3.9190616 0.81034483
#> 47  acc    3275-30662 2008-07-27 00:44:49 10 0.8338429 0.17241379
#> 48  acc    3275-30662 2008-07-27 00:45:01 50 4.1692145 0.86206897
#> 49  acc    3275-30662 2008-07-27 00:59:49  7 0.5836900 0.12068966
#> 50  acc    3275-30662 2008-07-27 01:00:01 53 4.4193674 0.91379310
#> 51  acc  unbanded-153 2008-07-27 00:00:51 43 3.5855245 0.74137931
#> 52  acc  unbanded-153 2008-07-27 00:01:03 17 1.4175329 0.29310345
#> 53  acc  unbanded-153 2008-07-27 00:14:51 16 1.3341486 0.27586207
#> 54  acc  unbanded-153 2008-07-27 00:15:03 44 3.6689088 0.75862069
#> 55  acc  unbanded-153 2008-07-27 00:29:50 13 1.0839958 0.22413793
#> 56  acc  unbanded-153 2008-07-27 00:30:02 47 3.9190616 0.81034483
#> 57  acc  unbanded-153 2008-07-27 00:44:49 10 0.8338429 0.17241379
#> 58  acc  unbanded-153 2008-07-27 00:45:01 50 4.1692145 0.86206897
#> 59  acc  unbanded-153 2008-07-27 00:59:49  7 0.5836900 0.12068966
#> 60  acc  unbanded-153 2008-07-27 01:00:01 53 4.4193674 0.91379310
#> 61  acc  unbanded-154 2008-07-27 00:00:51 38 3.1686030 0.65517241
#> 62  acc  unbanded-154 2008-07-27 00:01:03 22 1.8344544 0.37931034
#> 63  acc  unbanded-154 2008-07-27 00:14:51 16 1.3341486 0.27586207
#> 64  acc  unbanded-154 2008-07-27 00:15:03 44 3.6689088 0.75862069
#> 65  acc  unbanded-154 2008-07-27 00:29:50 13 1.0839958 0.22413793
#> 66  acc  unbanded-154 2008-07-27 00:30:02 47 3.9190616 0.81034483
#> 67  acc  unbanded-154 2008-07-27 00:44:49 10 0.8338429 0.17241379
#> 68  acc  unbanded-154 2008-07-27 00:45:01 50 4.1692145 0.86206897
#> 69  acc  unbanded-154 2008-07-27 00:59:49  7 0.5836900 0.12068966
#> 70  acc  unbanded-154 2008-07-27 01:00:01 53 4.4193674 0.91379310
#> 71  acc  unbanded-156 2008-07-27 00:00:15 53 4.4193674 0.91379310
#> 72  acc  unbanded-156 2008-07-27 00:00:27  7 0.5836900 0.12068966
#> 73  acc  unbanded-156 2008-07-27 00:14:51 16 1.3341486 0.27586207
#> 74  acc  unbanded-156 2008-07-27 00:15:03 44 3.6689088 0.75862069
#> 75  acc  unbanded-156 2008-07-27 00:29:50 13 1.0839958 0.22413793
#> 76  acc  unbanded-156 2008-07-27 00:30:02 47 3.9190616 0.81034483
#> 77  acc  unbanded-156 2008-07-27 00:44:49 10 0.8338429 0.17241379
#> 78  acc  unbanded-156 2008-07-27 00:45:01 50 4.1692145 0.86206897
#> 79  acc  unbanded-156 2008-07-27 00:59:49  7 0.5836900 0.12068966
#> 80  acc  unbanded-156 2008-07-27 01:00:01 53 4.4193674 0.91379310
#> 81  acc  unbanded-159 2008-07-27 00:00:03  8 0.6670743 0.13793103
#> 82  acc  unbanded-159 2008-07-27 00:00:15 52 4.3359831 0.89655172
#> 83  acc  unbanded-159 2008-07-27 00:14:51 16 1.3341486 0.27586207
#> 84  acc  unbanded-159 2008-07-27 00:15:03 44 3.6689088 0.75862069
#> 85  acc  unbanded-159 2008-07-27 00:29:50 13 1.0839958 0.22413793
#> 86  acc  unbanded-159 2008-07-27 00:30:02 47 3.9190616 0.81034483
#> 87  acc  unbanded-159 2008-07-27 00:44:49 10 0.8338429 0.17241379
#> 88  acc  unbanded-159 2008-07-27 00:45:01 50 4.1692145 0.86206897
#> 89  acc  unbanded-159 2008-07-27 00:59:49  7 0.5836900 0.12068966
#> 90  acc  unbanded-159 2008-07-27 01:00:01 53 4.4193674 0.91379310