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pathviewr


pathviewr offers tools to import, clean, and visualize movement data, particularly from motion capture systems such as Optitrack’s Motive, the Straw Lab’s Flydra, or other sources. We provide functions to remove artifacts, standardize tunnel position and tunnel axes, select a region of interest, isolate specific trajectories, fill gaps in trajectory data, and calculate 3D and per-axis velocity. For experiments of visual guidance, we also provide functions that use subject position to estimate perception of visual stimuli.

Installation

You can install pathviewr from CRAN via:

install.packages("pathviewr")

Or to get the latest (developmental) version through GitHub, use:

devtools::install_github("ropensci/pathviewr")

Example

Data import and cleaning via pathviewr

We’ll also load two tidyverse packages for wrangling & plotting in this readme.

library(pathviewr)
library(ggplot2)
library(magrittr)

We will import and clean a sample data set from .csv files exported by Optitrack’s Motive software. For examples of how to import and clean other types of data, see the Basics of data import and cleaning vignette.

## Import the Motive example data included in 
## the package

motive_data <-
  read_motive_csv(
    system.file("extdata", "pathviewr_motive_example_data.csv",
                package = 'pathviewr')
  )

Several functions to clean and wrangle data are available, and we have a suggested pipeline for how these steps should be handled. For this example, we will use one of two “all-in-one” functions: clean_viewr(). See the Basics of data import and cleaning vignette for the full pipeline and the other “all-in-one” function.

motive_allinone <-
  motive_data %>%
  clean_viewr(
    relabel_viewr_axes = TRUE,
    gather_tunnel_data = TRUE,
    trim_tunnel_outliers = TRUE,
    standardization_option = "rotate_tunnel",
    select_x_percent = TRUE,
    desired_percent = 50,
    rename_viewr_characters = FALSE,
    separate_trajectories = TRUE,
    max_frame_gap = "autodetect",
    get_full_trajectories = TRUE,
    span = 0.95
  )
#> autodetect is an experimental feature -- please report issues.

## Quick plot
## Colors correspond to unique trajectories (file_sub_traj)
motive_allinone %>%
  ggplot(aes(x = position_length, y = position_width, 
             fill = file_sub_traj)) +
  geom_point(pch = 21) +
  coord_fixed() +
  theme_classic() +
  theme(
    legend.position = "none"
  )

To get a sense of what we’ve done, compare the data before and after it has passed through the pipeline.

## Check out the data's structure before cleaning and wrangling:
str(motive_data)
#> tibble [934 × 26] (S3: tbl_df/tbl/data.frame)
#>  $ frame                     : int [1:934] 72210 72211 72212 72213 72214 72215 72216 72217 72218 72219 ...
#>  $ time_sec                  : num [1:934] 722 722 722 722 722 ...
#>  $ device02_rotation_x       : num [1:934] 0.1346 0.0819 0.2106 0.1961 0.1305 ...
#>  $ device02_rotation_y       : num [1:934] -0.977 -0.978 -0.973 -0.972 -0.975 ...
#>  $ device02_rotation_z       : num [1:934] -0.1117 -0.0991 -0.0939 -0.1275 -0.1213 ...
#>  $ device02_rotation_w       : num [1:934] 0.1215 0.1654 0.0311 0.0351 0.1315 ...
#>  $ device02_position_x       : num [1:934] 0.142 0.137 0.125 0.118 0.113 ...
#>  $ device02_position_y       : num [1:934] 0.16 0.164 0.166 0.168 0.173 ...
#>  $ device02_position_z       : num [1:934] 2 1.97 1.95 1.92 1.89 ...
#>  $ device02_mean_marker_error: num [1:934] 0.000113 0.000105 0.000115 0.000202 0.000106 0.000095 0.000114 0.000117 0.000121 0.000131 ...
#>  $ device03_rotation_x       : num [1:934] 0.107 0.111 0.109 0.109 0.108 ...
#>  $ device03_rotation_y       : num [1:934] -0.295 -0.295 -0.295 -0.295 -0.295 ...
#>  $ device03_rotation_z       : num [1:934] -0.088 -0.0866 -0.0853 -0.0853 -0.0879 ...
#>  $ device03_rotation_w       : num [1:934] 0.945 0.945 0.945 0.945 0.945 ...
#>  $ device03_position_x       : num [1:934] 0.222 0.222 0.222 0.222 0.222 ...
#>  $ device03_position_y       : num [1:934] 0.245 0.245 0.245 0.245 0.245 ...
#>  $ device03_position_z       : num [1:934] 0.0597 0.0597 0.0598 0.0598 0.0598 ...
#>  $ device03_mean_marker_error: num [1:934] 0.000166 0.000172 0.000164 0.000163 0.000162 0.000162 0.000169 0.00017 0.00017 0.000213 ...
#>  $ device05_rotation_x       : num [1:934] 0.00672 0.00714 0.00709 0.00742 0.00826 ...
#>  $ device05_rotation_y       : num [1:934] 0.944 0.944 0.944 0.944 0.944 ...
#>  $ device05_rotation_z       : num [1:934] -0.117 -0.116 -0.118 -0.118 -0.117 ...
#>  $ device05_rotation_w       : num [1:934] 0.308 0.308 0.309 0.31 0.308 ...
#>  $ device05_position_x       : num [1:934] 0.173 0.173 0.173 0.173 0.173 ...
#>  $ device05_position_y       : num [1:934] 0.243 0.243 0.243 0.243 0.243 ...
#>  $ device05_position_z       : num [1:934] 2.66 2.66 2.66 2.66 2.66 ...
#>  $ device05_mean_marker_error: num [1:934] 0.000241 0.000247 0.000255 0.000244 0.00023 0.000226 0.000231 0.000236 0.000242 0.000263 ...
#>  - attr(*, ".internal.selfref")=<externalptr> 
#>  - attr(*, "pathviewr_steps")= chr "viewr"
#>  - attr(*, "file_id")= chr "pathviewr_motive_example_data.csv"
#>  - attr(*, "file_mtime")= POSIXct[1:1], format: "2025-06-13 10:44:21"
#>  - attr(*, "frame_rate")= num 100
#>  - attr(*, "header")='data.frame':   11 obs. of  2 variables:
#>   ..$ metadata: chr [1:11] "Format Version" "Take Name" "Take Notes" "Capture Frame Rate" ...
#>   ..$ value   : chr [1:11] "1.23" "sept-18_mixed-group_16-30" "" "100.000000" ...
#>  - attr(*, "Motive_IDs")= chr [1:24] "\"9E207518D8A311E969D7AB6B1FACE49B\"" "\"9E207518D8A311E969D7AB6B1FACE49B\"" "\"9E207518D8A311E969D7AB6B1FACE49B\"" "\"9E207518D8A311E969D7AB6B1FACE49B\"" ...
#>  - attr(*, "subject_names_full")= chr [1:24] "device02" "device02" "device02" "device02" ...
#>  - attr(*, "subject_names_simple")= chr [1:3] "device02" "device03" "device05"
#>  - attr(*, "data_names")= chr [1:26] "frame" "time_sec" "device02_rotation_x" "device02_rotation_y" ...
#>  - attr(*, "data_types_full")= chr [1:24] "Rigid Body" "Rigid Body" "Rigid Body" "Rigid Body" ...
#>  - attr(*, "data_types_simple")= chr "Rigid Body"
#>  - attr(*, "d1")= chr [1:26] "" "" "Rotation" "Rotation" ...
#>  - attr(*, "d2")= chr [1:26] "Frame" "Time (Seconds)" "X" "Y" ...
#>  - attr(*, "import_method")= chr "motive"

## Check out the data's structure after cleaning and wrangling:
str(motive_allinone)
#> tibble [449 × 24] (S3: tbl_df/tbl/data.frame)
#>  $ frame            : int [1:449] 72213 72214 72215 72216 72217 72218 72219 72220 72221 72222 ...
#>  $ time_sec         : num [1:449] 722 722 722 722 722 ...
#>  $ subject          : chr [1:449] "device02" "device02" "device02" "device02" ...
#>  $ position_length  : num [1:449] 0.647 0.62 0.593 0.567 0.541 ...
#>  $ position_width   : num [1:449] -0.112 -0.116 -0.122 -0.134 -0.141 ...
#>  $ position_height  : num [1:449] -0.0371 -0.0324 -0.0273 -0.0235 -0.0209 ...
#>  $ rotation_length  : num [1:449] -0.128 -0.121 -0.105 -0.106 -0.149 ...
#>  $ rotation_width   : num [1:449] 0.1961 0.1305 0.0935 0.1798 0.164 ...
#>  $ rotation_height  : num [1:449] -0.972 -0.975 -0.975 -0.975 -0.972 ...
#>  $ rotation_real    : num [1:449] 0.0351 0.1315 0.1734 0.0807 0.0824 ...
#>  $ mean_marker_error: num [1:449] 0.000202 0.000106 0.000095 0.000114 0.000117 0.000121 0.000131 0.00014 0.000113 0.000114 ...
#>  $ velocity         : num [1:449] 2.73 2.78 2.84 2.85 2.68 ...
#>  $ length_inst_vel  : num [1:449] -2.65 -2.72 -2.74 -2.58 -2.56 ...
#>  $ width_inst_vel   : num [1:449] -0.642 -0.387 -0.58 -1.139 -0.75 ...
#>  $ height_inst_vel  : num [1:449] 0.184 0.475 0.508 0.379 0.258 ...
#>  $ traj_id          : int [1:449] 0 0 0 0 0 0 0 0 0 0 ...
#>  $ file_sub_traj    : chr [1:449] "pathviewr_motive_example_data.csv_device02_0" "pathviewr_motive_example_data.csv_device02_0" "pathviewr_motive_example_data.csv_device02_0" "pathviewr_motive_example_data.csv_device02_0" ...
#>  $ traj_length      : int [1:449] 63 63 63 63 63 63 63 63 63 63 ...
#>  $ start_length     : num [1:449] 0.647 0.647 0.647 0.647 0.647 ...
#>  $ end_length       : num [1:449] -0.656 -0.656 -0.656 -0.656 -0.656 ...
#>  $ length_diff      : num [1:449] 1.3 1.3 1.3 1.3 1.3 ...
#>  $ start_length_sign: num [1:449] 1 1 1 1 1 1 1 1 1 1 ...
#>  $ end_length_sign  : num [1:449] -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 ...
#>  $ direction        : chr [1:449] "leftwards" "leftwards" "leftwards" "leftwards" ...
#>  - attr(*, "file_id")= chr "pathviewr_motive_example_data.csv"
#>  - attr(*, "file_mtime")= POSIXct[1:1], format: "2025-06-13 10:44:21"
#>  - attr(*, "frame_rate")= num 100
#>  - attr(*, "header")='data.frame':   11 obs. of  2 variables:
#>   ..$ metadata: chr [1:11] "Format Version" "Take Name" "Take Notes" "Capture Frame Rate" ...
#>   ..$ value   : chr [1:11] "1.23" "sept-18_mixed-group_16-30" "" "100.000000" ...
#>  - attr(*, "Motive_IDs")= chr [1:24] "\"9E207518D8A311E969D7AB6B1FACE49B\"" "\"9E207518D8A311E969D7AB6B1FACE49B\"" "\"9E207518D8A311E969D7AB6B1FACE49B\"" "\"9E207518D8A311E969D7AB6B1FACE49B\"" ...
#>  - attr(*, "subject_names_full")= chr [1:24] "device02" "device02" "device02" "device02" ...
#>  - attr(*, "subject_names_simple")= chr [1:3] "device02" "device03" "device05"
#>  - attr(*, "data_names")= chr [1:26] "frame" "time_sec" "device02_rotation_x" "device02_rotation_y" ...
#>  - attr(*, "data_types_full")= chr [1:24] "Rigid Body" "Rigid Body" "Rigid Body" "Rigid Body" ...
#>  - attr(*, "data_types_simple")= chr "Rigid Body"
#>  - attr(*, "d1")= chr [1:26] "" "" "Rotation" "Rotation" ...
#>  - attr(*, "d2")= chr [1:26] "Frame" "Time (Seconds)" "X" "Y" ...
#>  - attr(*, "import_method")= chr "motive"
#>  - attr(*, "pathviewr_steps")= chr [1:10] "viewr" "renamed_tunnel" "gathered_tunnel" "artifacts_removed" ...
#>  - attr(*, "perch1_midpoint_original")= num [1:3] 0 0.2 0.205
#>  - attr(*, "perch2_midpoint_original")= num [1:3] 2.54 0.24 0.205
#>  - attr(*, "tunnel_centerpoint_original")= num [1:3] 1.27 0.22 0.205
#>  - attr(*, "rotation_degrees")= num 0.902
#>  - attr(*, "rotation_radians")= num 0.0157
#>  - attr(*, "perch1_midpoint_current")= num [1:3] -1.27 4.65e-15 2.05e-01
#>  - attr(*, "perch2_midpoint_current")= num [1:3] 1.27 -4.65e-15 2.05e-01
#>  - attr(*, "percent_selected")= num 50
#>  - attr(*, "full_tunnel_length")= num 2.64
#>  - attr(*, "selected_tunnel_length")= num 1.32
#>  - attr(*, "max_frame_gap")= int [1:3] 1 1 2
#>  - attr(*, "span")= num 0.95
#>  - attr(*, "trajectories_removed")= int 5

An important aspect of how pathviewr defines trajectories is by managing gaps in the data. See the vignette on Managing frame gaps for more information on trajectory definition and frame gaps.

Now that the data is cleaned, pathviewr includes functions that estimate visual perceptions based on the distance between the subject/observer and visual stimuli on the walls of the experimental tunnel. For a complete description of these functions, see the vignette on Estimating visual perceptions from tracking data.

Add more info about experiments

Now that our objects have been cleaned, we will use insert_treatments() to add information about the experiments that are necessary for calculating visual perceptions.

The data from this example were recorded in a V-shaped tunnel. Accordingly, the vertex angle and vertex height of the tunnel, along with information about the visual stimuli used during the experiment, will be added to the data to inform calculations of visual perception (next section).

motive_V <- 
  motive_allinone %>%
  insert_treatments(
    tunnel_config = "v",
    perch_2_vertex = 0.4,
    vertex_angle = 90,
    tunnel_length = 2,
    stim_param_lat_pos = 0.1,
    stim_param_lat_neg = 0.1,
    stim_param_end_pos = 0.3,
    stim_param_end_neg = 0.3,
    treatment = "lat10_end_30"
  ) 

Estimate perception of visual stimuli

To calculate the spatial frequency of the visual stimuli as perceived by the subject some distance from the stimuli, we will use get_sf().

This will require two intermediate steps: 1) calculating the minimum distance between a subject and each wall (via calc_min_dist_v()) and 2) estimating the visual angles from the subject’s perspective (get_vis_angle()).

motive_V_sf <- 
  motive_V %>%
  calc_min_dist_v(simplify_output = TRUE) %>%
  get_vis_angle() %>%
  get_sf()

Visualizing the calculations provides an more intuitive understanding of how these visual perceptions change as the subject moves throughout the tunnel. Please see the vignette on Estimating visual perceptions from tracking data for more examples of visualizing calculations.

ggplot(motive_V_sf, aes(x = position_width, y = position_height)) +
  geom_point(aes(color = sf_pos), shape=1, size=3) +
  geom_segment(aes(x = 0,         # dimensions of the positive wall
                  y = -0.3855,
                  xend = 0.5869,
                  yend = 0.2014)) +
  geom_segment(aes(x = 0,         # dimensions of the negative wall
                   y = -0.3855,
                   xend = -0.5869,
                   yend = 0.2014)) +
  coord_fixed() +
  theme_classic() +
  theme(
    legend.position = "none"
  )
#> Warning in geom_segment(aes(x = 0, y = -0.3855, xend = 0.5869, yend = 0.2014)): All aesthetics have length 1, but the data has 449 rows.
#> ℹ Please consider using `annotate()` or provide this layer with data containing
#>   a single row.
#> Warning in geom_segment(aes(x = 0, y = -0.3855, xend = -0.5869, yend = 0.2014)): All aesthetics have length 1, but the data has 449 rows.
#> ℹ Please consider using `annotate()` or provide this layer with data containing
#>   a single row.

Contributing and/or raising Issues

We welcome feedback on bugs, improvements, and/or feature requests. Please see our Issues templates on GitHub to make a bug fix request or feature request.

To contribute code via a pull request, please consult our Contributing Guide first.

Citation

The preferred way to cite pathviewr (but subject to change) is:

Baliga VB, Armstrong MS, Press ER (2021). pathviewr: Tools to import, clean, and visualize animal movement data in R. R package version 1.1.8, https://github.com/ropensci/pathviewr. doi: 10.5281/zenodo.4270187

License

GPL (>= 3) + file LICENSE

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install.packages('pathviewr')

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Version

1.1.8

License

GPL-3

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Maintainer

Vikram B. Baliga

Last Published

June 16th, 2025

Functions in pathviewr (1.1.8)

fill_traj_gaps

Interpolate gaps within trajectories
get_dist_point_line

Compute distance between a point and a line
get_full_trajectories

Retain trajectories that span a selected region of interest
find_curve_elbow

Find the "elbow" of a curve.
get_3d_cross_prod

Compute the cross product of two 3D vectors
get_2d_angle

Compute an angle in 2D space
get_traj_velocities

Recompute trajectory-specific velocities
get_velocity

Get instantaneous velocity for subjects
import_batch

Batch import of files for either Motive or Flydra (but not a mix of both)
get_vis_angle

Estimate visual angles from a subject's perspective in an experimental tunnel
insert_treatments

Inserts treatment and experiment information
rename_viewr_characters

Rename subjects in the data via pattern detection
quick_separate_trajectories

Quick version of separate_trajectories()
rad_2_deg

Convert radians to degrees
trim_tunnel_outliers

Trim out artifacts and other outliers from the extremes of the tunnel
standardize_tunnel

Rotate and center a tunnel based on landmarks
rescale_tunnel_data

Rescale position data within a viewr object
set_traj_frametime

Redefine frames and time stamps on a per-trajectory basis
separate_trajectories

Separate rows of data into separately labeled trajectories.
exclude_by_velocity

Remove trajectories entirely, based on velocity thresholds
calc_min_dist_box

Calculate minimum distance to lateral and end walls in a box-shaped experimental tunnel
as_viewr

Convert data from another format into a viewr object
clean_by_span

Remove file_sub_traj entries that do not span the full region of interest
clean_viewr

All-in-one function to clean imported objects
gather_tunnel_data

Gather data columns into key-value pairs
calc_min_dist_v

Calculate minimum distance to lateral and end walls in a V-shaped experimental tunnel
get_header_viewr

Extract header info from imported viewr object
import_and_clean_batch

Batch import and clean files
import_and_clean_viewr

Import + clean_viewr()
get_3d_angle

Compute an angle in 3D space
read_motive_csv

Import data from a CSV exported from Optitrack's Motive software
plot_viewr_trajectories

Plot each trajectory within a viewr object
read_flydra_mat

Import data from a MAT file exported from Flydra software
plot_by_subject

Plot trajectories and density plots of position by subject
clean_viewr_batch

Batch clean viewr files
deg_2_rad

Convert degrees to radians
visualize_frame_gap_choice

Visualize the consequence of using various max_frame_gap values
get_sf

Estimate the spatial frequency of visual stimuli from the subject's perspective in an experimental tunnel.
bind_viewr_objects

Bind viewr objects
pathviewr-package

pathviewr: Wrangle, Analyze, and Visualize Animal Movement Data
section_tunnel_by

Bin data along a specified axis
redefine_tunnel_center

"Center" the tunnel data, i.e. translation but no rotation
%>%

Pipe operator
relabel_viewr_axes

Relabel the dimensions as length, width, and height
rotate_tunnel

Rotate a tunnel so that perches are approximately aligned
remove_duplicate_frames

Remove any duplicates or aliased frames within trajectories
rm_by_trajnum

Remove subjects by trajectory number
remove_vel_anomalies

Remove any rows which show sharp shifts in velocity that are likely due to tracking errors
select_x_percent

Select a region of interest within the tunnel