Package 'flowcam'

Build full image URLs from camera metadata and filenames

Description

Combines a camera's base directory with one or more filenames returned by list_images() to produce download-ready image URLs.

Usage

build_image_url(camera_row, filename, size = c("small", "overlay", "thumb"))

Arguments

camera_row	A single-row tibble (or named list) from find_cameras(). Must contain the directory column corresponding to size.
filename	Character vector of one or more filenames from list_images().
size	Image size. One of: "small" (default): ~720 px wide (smallDir) "overlay": full-size overlay image (overlayDir) "thumb": thumbnail ~200 px tall (thumbDir)

Value

A character vector of full image URLs, one per element of filename.

Examples

## Not run: 
cam   <- find_cameras(cam_id = "WI_Chippewa_River_at_Grand_Ave_at_Eau_Claire")
imgs  <- list_images(cam$camId[[1]], limit = 5)
urls  <- build_image_url(cam, imgs$filename, size = "small")

## End(Not run)

---

Download camera images to disk

Description

Lists available images for a camera and downloads them to a local directory. Images are fetched directly from USGS S3 storage; no API key is required for the downloads themselves.

Usage

download_images(
  cam_id = NULL,
  dest_dir,
  size = "small",
  limit = 1000L,
  time = NULL,
  overwrite = FALSE,
  site_id = NULL
)

Arguments

cam_id	Character. Camera identifier. Use find_cameras() to look up valid IDs. Cannot be used together with site_id.
dest_dir	Character. Path to an existing local directory where images will be saved.
size	Image size passed to build_image_url(). One of "small" (default), "overlay", or "thumb".
limit	Integer between 1 and 50000. Page size for the internal list_images() call. Default is 1000. All images in the requested time range are downloaded via automatic pagination.
time	POSIXct, Date, or character vector of length 1 or 2 used to filter images by capture time. A length-1 value is treated as a start (on or after). A length-2 vector sets the start and end; use NA for an open bound. See list_images() for full details.
overwrite	Logical. If FALSE (default), skip files that already exist in dest_dir (resume behaviour).
site_id	Character. NWIS site number (e.g. "05366800" or "USGS-05366800"). Cannot be used together with cam_id. If the site has more than one camera, supply cam_id directly.

Details

Identify the camera with either cam_id or site_id — provide exactly one. site_id accepts both bare NWIS numbers ("05366800") and the ⁠USGS-⁠ prefixed form ("USGS-05366800"). When a site has multiple cameras, specify the desired camera via cam_id instead.

Value

A character vector of local file paths, invisibly. Failed downloads are represented as NA.

Examples

## Not run: 
# By cam_id
paths <- download_images(
  "WI_Chippewa_River_at_Grand_Ave_at_Eau_Claire",
  dest_dir = tempdir(),
  limit    = 5
)

# By USGS site ID
paths <- download_images(
  site_id  = "USGS-05366800",
  dest_dir = tempdir(),
  limit    = 5
)

## End(Not run)

---

Query NIMS cameras

Description

Returns a tibble of camera metadata from the USGS National Imagery Management System (NIMS). With no arguments, all cameras are returned. Filter by a NWIS site ID or a specific camera ID.

Usage

find_cameras(site_id = NULL, cam_id = NULL, return_fields = NULL)

Arguments

site_id	Character. NWIS site number (e.g. "05366800"). Cannot be used together with cam_id.
cam_id	Character. Camera identifier (e.g. "WI_Chippewa_River_at_Grand_Ave_at_Eau_Claire"). Cannot be used together with site_id.
return_fields	Character vector of camera fields to include in the response (e.g. c("camName", "newestImageDT")). camId is always returned regardless of this setting. When NULL (the default), all fields are returned.

Value

A tibble with one row per camera. Columns depend on return_fields. lat and lng are returned as numeric. Datetime columns are POSIXct (UTC). The ingest column is a list-column containing each camera's ingestion configuration.

Examples

## Not run: 
# All cameras
find_cameras()

# Cameras at a specific gage
find_cameras(site_id = "05366800")

# A specific camera
find_cameras(cam_id = "WI_Chippewa_River_at_Grand_Ave_at_Eau_Claire")

# Only selected fields
find_cameras(return_fields = c("camName", "newestImageDT"))

## End(Not run)

---

Query NIMS cameras and enrich with NWIS site metadata

Description

Calls find_cameras() for the given NWIS site ID, then joins the result with site metadata from dataRetrieval::read_waterdata_monitoring_location(). Optionally appends a data_types list-column with the available time series at the site via get_site_data_availability(). Requires the dataRetrieval package.

Usage

find_gage_cameras(site_id, include_availability = TRUE)

Arguments

site_id	Character. A single 8-to-15-digit NWIS site number (e.g. "05366800").
include_availability	Logical. When TRUE (default), a data_types list-column is appended containing a tibble of available time series for the site (from get_site_data_availability()). Set to FALSE to skip this extra API call and return only the camera and site metadata.

Value

A tibble with all camera columns from find_cameras() plus these site metadata columns when available: monitoring_location_name, state_name, county_name, hydrologic_unit_code, drainage_area (total drainage area in square miles), and altitude (elevation in feet above the stated vertical datum). When include_availability = TRUE, a data_types list-column is also included; each element is a tibble with columns from get_site_data_availability().

Examples

## Not run: 
# With available time series (default)
find_gage_cameras("05366800")

# Site metadata only, no data availability call
find_gage_cameras("05366800", include_availability = FALSE)

## End(Not run)

---

Retrieve historical flow statistics for a USGS gage

Description

Provides historical context for interpreting camera imagery — "is this flow high or low?" — by returning day-of-year percentile curves or period-of-record summaries.

Usage

get_flow_statistics(
  site_id = NULL,
  cam_id = NULL,
  parameter_code = "00060",
  type = c("daily_normals", "period_summary"),
  computation = "percentile",
  time = NULL
)

Arguments

site_id	Character. A single NWIS site number (e.g. "05366800" or "USGS-05366800"). Exactly one of site_id or cam_id must be provided.
cam_id	Character. A camera identifier. If supplied, the function resolves the associated NWIS site ID via find_cameras(). Exactly one of site_id or cam_id must be provided.
parameter_code	Character. One or more five-digit USGS parameter codes. Default "00060" (discharge, ft³/s).
type	Character. "daily_normals" (default) returns day-of-year and month-of-year percentile/statistic curves, suitable for overlaying on a time series plot. "period_summary" returns calendar-month, calendar-year, and water-year summaries.
computation	Character vector. One or more of "percentile" (default), "arithmetic_mean", "minimum", "maximum", "median". When NULL or NA, all computation types are returned.
time	For type = "period_summary" only. A POSIXct, Date, or character vector of length 1 or 2 (start, end) used to restrict the date range of the summary. Follows the same semantics as the time argument in get_site_streamflow(). NULL (default) returns the full period of record. Ignored when type = "daily_normals".

Details

Wraps dataRetrieval::read_waterdata_stats_por() (type = "daily_normals") or dataRetrieval::read_waterdata_stats_daterange() (type = "period_summary").

Value

A tibble. All types include columns:

site_id

Bare NWIS site number.

parameter_code

Five-digit parameter code.

unit_of_measure

Units string.

computation

Statistical method (e.g. "percentile").

percentile

Integer percentile (e.g. 50L); NA for non-percentile computations.

value

Numeric statistic value.

sample_count

Number of observations used to compute the statistic.

type = "daily_normals" additionally includes:

month_day

Character MM-DD representing the day or month of year.

type = "period_summary" additionally includes:

interval_type

One of "calendar_month", "calendar_year", or "water_year".

start_date

Date. Start of the summary interval.

end_date

Date. End of the summary interval.

Returns a zero-row tibble (with correct column types) when no data are found. Requires the dataRetrieval package.

Examples

## Not run: 
# Day-of-year discharge percentile curves (the 10/25/50/75/90th percentiles)
get_flow_statistics("05366800")

# Annual and monthly discharge summaries
get_flow_statistics("05366800", type = "period_summary")

# Restrict period_summary to a specific date range
get_flow_statistics(
  "05366800",
  type = "period_summary",
  time = c("2010-01-01", "2020-12-31")
)

# Multiple computation types
get_flow_statistics(
  "05366800",
  computation = c("minimum", "median", "maximum")
)

# Overlay on a streamflow time series
flow  <- get_site_streamflow("05366800", time = "P1Y")
stats <- get_flow_statistics("05366800")

## End(Not run)

---

Find cameras on the same stream network

Description

Uses the USGS Network Linked Data Index (NLDI) to navigate upstream and/or downstream from a gage site, then returns all flowcam cameras found along the network within a specified distance.

Usage

get_network_cameras(
  site_id = NULL,
  cam_id = NULL,
  direction = c("upstream", "downstream", "both"),
  distance_km = 100
)

Arguments

site_id	Character. A single NWIS site number (e.g. "05366800" or "USGS-05366800"). Exactly one of site_id or cam_id must be provided.
cam_id	Character. A camera identifier. If supplied, the function resolves the associated NWIS site ID via find_cameras(). Exactly one of site_id or cam_id must be provided.
direction	Character. Navigation direction(s): "upstream" (upstream tributary), "downstream" (downstream mainstem), or "both". Default "upstream".
distance_km	Numeric. How far (in kilometres) to navigate along the stream network from the origin site. Default 100.

Details

Useful for anticipating flood wave arrival, comparing conditions across a watershed, or discovering monitoring locations on the same river system.

Wraps dataRetrieval::findNLDI().

Value

A tibble with one row per camera (including the origin site) and columns:

site_id

Bare NWIS site number.

cam_id

Camera identifier.

cam_name

Human-readable camera name.

direction

"origin", "upstream", or "downstream".

lat

Latitude (decimal degrees, WGS84).

lng

Longitude (decimal degrees, WGS84).

Returns a zero-row tibble when no networked cameras are found (including the origin site if it has no camera). Requires the dataRetrieval package.

Examples

## Not run: 
# Cameras upstream of a site (within 100 km)
get_network_cameras("05366800")

# Cameras both upstream and downstream (150 km)
get_network_cameras("05366800", direction = "both", distance_km = 150)

# Via camera ID
get_network_cameras(
  cam_id = "WI_Chippewa_River_at_Grand_Ave_at_Eau_Claire",
  direction = "downstream"
)

## End(Not run)

---

Discover available time series at a USGS gage

Description

Returns metadata about every time series recorded at a site — parameter codes, units, and period of record — so you know exactly which codes to pass to get_site_streamflow().

Usage

get_site_data_availability(
  site_id = NULL,
  cam_id = NULL,
  parameter_code = NA_character_
)

Arguments

site_id	Character. A single NWIS site number (e.g. "05366800" or "USGS-05366800"). Exactly one of site_id or cam_id must be provided.
cam_id	Character. A camera identifier. If supplied, the function resolves the associated NWIS site ID via find_cameras(). Exactly one of site_id or cam_id must be provided.
parameter_code	Character. One or more five-digit USGS parameter codes to filter results (e.g. "00060" for discharge). Default NA returns all available parameters.

Details

Wraps dataRetrieval::read_waterdata_ts_meta().

Value

A tibble with columns:

site_id

Bare NWIS site number (without ⁠USGS-⁠ prefix).

parameter_code

Five-digit parameter code.

parameter_name

Human-readable parameter name.

unit_of_measure

Units string (e.g. "ft3/s").

begin_utc

POSIXct (UTC). Earliest observation in this time series.

end_utc

POSIXct (UTC). Most recent observation.

statistic_id

Five-digit statistic code (e.g. "00003" for mean).

time_series_id

Unique identifier for this time series.

Rows are sorted by parameter_code. Returns a zero-row tibble when no time series are found. Requires the dataRetrieval package.

Examples

## Not run: 
# All parameters at a site
get_site_data_availability("05366800")

# Discharge only
get_site_data_availability("05366800", parameter_code = "00060")

# Via camera ID
get_site_data_availability(
  cam_id = "WI_Chippewa_River_at_Grand_Ave_at_Eau_Claire"
)

# Chain with get_site_streamflow():
avail <- get_site_data_availability("05366800")
flow  <- get_site_streamflow("05366800",
                             parameter_code = avail$parameter_code[1])

## End(Not run)

---

Retrieve manual field measurements for a USGS gage

Description

Returns the record of in-person discharge measurements made by USGS hydrographers at a gage site. These manual measurements are the "ground truth" used to build stage-discharge rating curves, and they provide direct visual correlates to camera imagery taken at the same location and time.

Usage

get_site_field_measurements(
  site_id = NULL,
  cam_id = NULL,
  time = NULL,
  parameter_code = "00060"
)

Arguments

site_id	Character. A single NWIS site number (e.g. "05366800" or "USGS-05366800"). Exactly one of site_id or cam_id must be provided.
cam_id	Character. A camera identifier. If supplied, the function resolves the associated NWIS site ID via find_cameras(). Exactly one of site_id or cam_id must be provided.
time	POSIXct, Date, or character vector of length 1 or 2 specifying the time window. Follows the same semantics as get_site_streamflow(). NULL (default) returns all available measurements.
parameter_code	Character. One or more five-digit USGS parameter codes. Default "00060" (discharge, ft³/s). NULL returns measurements for all parameters.

Details

Wraps dataRetrieval::read_waterdata_field_measurements().

Value

A tibble with columns:

site_id

Bare NWIS site number.

datetime

POSIXct (UTC) of the measurement.

value

Numeric measured value.

unit

Units of measure (e.g. "ft3/s").

parameter_code

Five-digit parameter code.

approval_status

"Approved" or "Provisional".

measurement_rated

Quality rating of the measurement: "Excellent" (≤2% error), "Good" (≤5%), "Fair" (≤8%), or "Poor" (>8%).

control_condition

Description of channel control conditions during the measurement.

Returns a zero-row tibble (with correct column types) when no measurements are found. Compatible with get_site_streamflow() output via dplyr::bind_rows() on the shared columns. Requires the dataRetrieval package.

Examples

## Not run: 
# All discharge measurements at a site
get_site_field_measurements("05366800")

# Measurements during a specific period
get_site_field_measurements(
  "05366800",
  time = c("2020-01-01", "2024-12-31")
)

# Via camera ID
get_site_field_measurements(
  cam_id = "WI_Chippewa_River_at_Grand_Ave_at_Eau_Claire"
)

# Compare field measurements against continuous sensor record
field <- get_site_field_measurements("05366800", time = "P2Y")
sensor <- get_site_streamflow("05366800", time = "P2Y")

## End(Not run)

---

Retrieve streamflow data for a USGS gage

Description

Wraps dataRetrieval::read_waterdata_continuous() (instantaneous values) or dataRetrieval::read_waterdata_daily() (daily mean values) for the USGS gage associated with a flowcam camera. Returns a clean tibble aligned with flowcam conventions.

Usage

get_site_streamflow(
  site_id = NULL,
  cam_id = NULL,
  time = NULL,
  parameter_code = "00060",
  type = c("continuous", "daily"),
  water_year = FALSE
)

Arguments

site_id	Character. A single NWIS site number (e.g. "05366800" or "USGS-05366800"). Exactly one of site_id or cam_id must be provided.
cam_id	Character. A camera identifier (e.g. "WI_Chippewa_River_at_Grand_Ave_at_Eau_Claire"). If supplied, the function resolves the associated NWIS site ID via find_cameras(). Exactly one of site_id or cam_id must be provided.
time	POSIXct, Date, or character vector of length 1 or 2. Follows the same semantics as the time argument in list_images(): length-1 is treated as a start bound; length-2 sets start and end, with NA for an open bound. ISO 8601 duration strings such as "P7D" (last 7 days) or "P1Y" (last year) are also accepted and forwarded to the API unchanged. When NULL, the API default applies (approximately the last year of data for continuous; all available data for daily).
parameter_code	Character. One or more five-digit USGS parameter codes. Default "00060" is discharge in cubic feet per second. Other common codes: "00010" (water temperature, $°C$), "00065" (gage height, ft), "00095" (specific conductance, µS/cm). When multiple codes are supplied, all parameters are returned in a single tibble distinguished by the parameter_code column.
type	Character. "continuous" (default) returns instantaneous (unit-value) observations; "daily" returns daily mean values.
water_year	Logical. When TRUE, appends a water_year integer column (Oct 1 – Sep 30) to the result using dataRetrieval::calcWaterYear(). Default FALSE.

Value

A tibble with columns:

site_id

Bare NWIS site number (without ⁠USGS-⁠ prefix).

datetime

POSIXct (UTC) for type = "continuous"; Date for type = "daily".

value

Numeric observation value.

unit

Units of measure (e.g. "ft3/s").

parameter_code

Five-digit parameter code.

approval_status

"Approved" or "Provisional".

water_year

Integer water year (only present when water_year = TRUE).

Returns a zero-row tibble (with correct column types) when no data are found. Requires the dataRetrieval package.

Examples

## Not run: 
# Instantaneous discharge for the last 7 days
get_site_streamflow("05366800", time = "P7D")

# Daily discharge for a calendar year
get_site_streamflow(
  "05366800",
  time = c("2024-01-01", "2024-12-31"),
  type = "daily"
)

# Water temperature from a camera ID
get_site_streamflow(
  cam_id = "WI_Chippewa_River_at_Grand_Ave_at_Eau_Claire",
  parameter_code = "00010"
)

# Multiple parameters at once
get_site_streamflow("05366800", parameter_code = c("00060", "00065"))

# Include water year column
get_site_streamflow("05366800", time = "P1Y", water_year = TRUE)

# Pair with image timestamps
images <- list_images("05366800", time = c("2024-10-01", "2024-10-07"),
                      raw_item = TRUE)
flow   <- get_site_streamflow("05366800",
                              time = c("2024-10-01", "2024-10-07"))

## End(Not run)

---

Get the timelapse video URL for a camera

Description

Queries the camera's metadata from NIMS and constructs the URL to its timelapse video file (720p MP4). Issues a warning if timelapse is not enabled for the camera.

Usage

get_timelapse_url(cam_id)

Arguments

cam_id

Character. Camera identifier.

Value

A single character string with the full timelapse video URL.

Examples

## Not run: 
get_timelapse_url("WI_Chippewa_River_at_Grand_Ave_at_Eau_Claire")

## End(Not run)

---

List image filenames for a NIMS camera

Description

Returns a tibble of image filenames (or raw image metadata) for the specified camera. Use the filenames with build_image_url() to construct full image URLs.

Usage

list_images(
  cam_id = NULL,
  limit = 1000L,
  recent = TRUE,
  time = NULL,
  raw_item = FALSE,
  site_id = NULL
)

Arguments

cam_id	Character. Camera identifier. Use find_cameras() to look up valid IDs. Cannot be used together with site_id.
limit	Integer between 1 and 50000. Number of records fetched per API request (page size). Default is 1000. All matching images are returned via automatic pagination regardless of this value.
recent	Logical. If TRUE (default), return the most recent images first. If FALSE, return the oldest images first.
time	POSIXct, Date, or character vector of length 1 or 2 used to filter images by capture time. A length-1 value is treated as a start (on or after). A length-2 vector sets the start and end; use NA for an open bound (c("2025-06-01", NA) = on or after; c(NA, "2025-06-02") = on or before). Character strings are passed through unchanged; the API accepts ISO 8601 ("2025-12-31T00:00:00") and NIMS format ("2025-12-31T00-00-00Z").
raw_item	Logical. If TRUE, return a tibble with columns camId, filename, timestamp, and fs (file size in kb). If FALSE (default), return a single-column tibble of filenames.
site_id	Character. NWIS site number (e.g. "05366800" or "USGS-05366800"). Cannot be used together with cam_id. If the site has more than one camera, supply cam_id directly.

Details

Identify the camera with either cam_id or site_id — provide exactly one. site_id accepts both bare NWIS numbers ("05366800") and the ⁠USGS-⁠ prefixed form ("USGS-05366800"). When a site has multiple cameras, specify the desired camera via cam_id instead.

Value

A tibble. When raw_item = FALSE, one column: filename. When raw_item = TRUE, four columns: camId, filename, timestamp, fs.

Examples

## Not run: 
# 10 most recent images by cam_id
list_images("WI_Chippewa_River_at_Grand_Ave_at_Eau_Claire", limit = 10)

# By USGS site ID (bare or prefixed)
list_images(site_id = "05366800", limit = 10)
list_images(site_id = "USGS-05366800", limit = 10)

# Images in a date window
list_images(
  "WI_Chippewa_River_at_Grand_Ave_at_Eau_Claire",
  time = as.POSIXct(c("2025-06-01", "2025-06-02"), tz = "UTC")
)

# Open-ended: on or after June 1
list_images(
  "WI_Chippewa_River_at_Grand_Ave_at_Eau_Claire",
  time = c("2025-06-01", NA)
)

# With metadata
list_images("WI_Chippewa_River_at_Grand_Ave_at_Eau_Claire",
            limit = 5, raw_item = TRUE)

## End(Not run)

---

Assemble camera images into an animated GIF

Description

Downloads images for a camera over a specified time range and assembles them into an animated GIF using the gifski package. Provide either cam_id or site_id to identify the camera, and use time to restrict the range.

Usage

make_gif(
  cam_id = NULL,
  site_id = NULL,
  time = NULL,
  output = NULL,
  fps = 2,
  size = "small",
  limit = 1000L,
  dir = NULL,
  one_per_day = FALSE
)

Arguments

cam_id	Character. Camera identifier. Cannot be used with site_id.
site_id	Character. NWIS site number (e.g. "05366800" or "USGS-05366800"). Cannot be used with cam_id.
time	POSIXct, Date, or character vector of length 1 or 2. Same semantics as download_images(). When dir is supplied, timestamps are parsed from the filenames (NIMS format: ⁠<camId>___<timestamp>.jpg⁠).
output	Character. File path for the output GIF. Defaults to "<cam_id>.gif" (or "<site_id>.gif", or the directory basename) in the working directory.
fps	Positive number. Frames per second. Any positive value is accepted. Default is 2.
size	Image size passed to download_images(). One of "small" (default), "overlay", or "thumb". Ignored when dir is supplied.
limit	Integer. Page size for the internal list_images() call. Default is 1000. Ignored when dir is supplied.
dir	Character. Path to a local directory of already-downloaded images. When supplied, downloads are skipped and JPEG/PNG files are read from this directory. cam_id/site_id and time still apply as filters.
one_per_day	Logical. If TRUE, reduce frames to one per calendar day by selecting the image whose capture time is closest to noon in the camera's local timezone (from the tz field of find_cameras()). Default is FALSE.

Details

When dir is supplied, images are read from that local directory instead of being downloaded. You can still pass cam_id/site_id to select only files belonging to a particular camera (matched by filename prefix) and time to filter by timestamp embedded in the filename — useful when a directory contains images from multiple cameras or a wider date range than needed.

JPEG frames are converted to PNG in a temporary directory before encoding because gifski only accepts PNG input. The jpeg and png packages are required when any frames are JPEG.

Value

The output file path, invisibly.

Examples

## Not run: 
# Download and assemble images for a date range
make_gif("WI_Chippewa_River_at_Grand_Ave_at_Eau_Claire",
         time = c("2025-06-01", "2025-06-02"), output = "chippewa.gif")

# One frame per day from a local directory
make_gif(cam_id = "NM_Pecos_Web_Camera_near_Roswell",
         time        = c("2023-08-01", "2023-08-31"),
         dir         = "~/Downloads/Pecos",
         one_per_day = TRUE,
         output      = "pecos_august.gif")

## End(Not run)

---

Assemble camera images into an MP4 video

Description

Downloads images for a camera over a specified time range and encodes them into an MP4 video using the av package. Provide either cam_id or site_id to identify the camera, and use time to restrict the range.

Usage

make_video(
  cam_id = NULL,
  site_id = NULL,
  time = NULL,
  output = NULL,
  fps = 2,
  size = "small",
  limit = 1000L,
  dir = NULL,
  one_per_day = FALSE
)

Arguments

cam_id	Character. Camera identifier. Cannot be used with site_id.
site_id	Character. NWIS site number (e.g. "05366800" or "USGS-05366800"). Cannot be used with cam_id.
time	POSIXct, Date, or character vector of length 1 or 2. Same semantics as download_images(). When dir is supplied, timestamps are parsed from the filenames (NIMS format: ⁠<camId>___<timestamp>.jpg⁠).
output	Character. File path for the output MP4. Defaults to "<cam_id>.mp4" (or "<site_id>.mp4", or the directory basename) in the working directory.
fps	Positive number. Frames per second. Any positive value is accepted. Default is 2.
size	Image size passed to download_images(). One of "small" (default), "overlay", or "thumb". Ignored when dir is supplied.
limit	Integer. Page size for the internal list_images() call. Default is 1000. Ignored when dir is supplied.
dir	Character. Path to a local directory of already-downloaded images. When supplied, downloads are skipped and JPEG/PNG files are read from this directory. cam_id/site_id and time still apply as filters.
one_per_day	Logical. If TRUE, reduce frames to one per calendar day by selecting the image whose capture time is closest to noon in the camera's local timezone (from the tz field of find_cameras()). Default is FALSE.

Details

When dir is supplied, images are read from that local directory instead of being downloaded. You can still pass cam_id/site_id to select only files belonging to a particular camera (matched by filename prefix) and time to filter by timestamp embedded in the filename — useful when a directory contains images from multiple cameras or a wider date range than needed.

Value

The output file path, invisibly.

Examples

## Not run: 
# Download and assemble images for a date range
make_video("WI_Chippewa_River_at_Grand_Ave_at_Eau_Claire",
           time = c("2025-06-01", "2025-06-02"), output = "chippewa.mp4")

# One frame per day from a local directory
make_video(cam_id = "NM_Pecos_Web_Camera_near_Roswell",
           time        = c("2023-08-01", "2023-08-31"),
           dir         = "~/Downloads/Pecos",
           one_per_day = TRUE,
           output      = "pecos_august.mp4")

## End(Not run)

---

Store your USGS API key in .Renviron

Description

Writes API_USGS_PAT to the user's ⁠~/.Renviron⁠ file and applies it immediately in the current session. The same variable is used by package dataRetrieval, so one key can be shared across both packages.

Usage

set_usgs_api_key(key)

Arguments

key	A single non-empty character string containing your API key.

Details

Register for a free API key at https://api.waterdata.usgs.gov/signup/.

Value

key, invisibly.

Examples

## Not run: 
set_usgs_api_key("my_api_key_here")

## End(Not run)

---