Get a scan (scan) from a polar volume (pvol)

Returns the scan (scan) from a polar volume (pvol) with elevation angle closest to elev.

Usage

get_scan(x, elev, all = FALSE)

Arguments

x

A pvol object.

elev

Numeric. Elevation angle in degrees.

all

Logical. Return the first scan in the pvol object closest to the requested elevation (FALSE), or a list with all scans equally close to the requested elevation (TRUE).

Value

A scan object when all equals FALSE (default), or a list of scan objects if all equals TRUE

Details

In cases where elev is exactly in between two scan elevation angles, the lower elevation angle scan is returned.

See also

Other scan functions: example_scan, get_elevation_angles(), plot.scan(), summary.scan(), tidyverse

Examples

# Locate and read the polar volume example file
pvolfile <- system.file("extdata", "volume.h5", package = "bioRad")
pvol <- read_pvolfile(pvolfile)

# Get elevation angles
get_elevation_angles(pvol)
#> [1] 0.5 1.5 2.5

# Extract the scan closest to 3 degrees elevation (2.5 degree scan)
scan <- get_scan(pvol, 3)

# Get summary info
scan
#>                   Polar scan (class scan)
#> 
#>      parameters:  DBZH VRADH RHOHV ZDR PHIDP 
#> elevation angle:  2.5 deg
#>            dims:  480 bins x 360 rays

# Extract all scans closest to 3 degrees elevation (2.5 degree scan)
# Always returns a list with scan object(s), containing multiple scans
# if the pvol contains multiple scans at the same closest elevation.
scan_list <- get_scan(pvol, 3)
scan_list
#>                   Polar scan (class scan)
#> 
#>      parameters:  DBZH VRADH RHOHV ZDR PHIDP 
#> elevation angle:  2.5 deg
#>            dims:  480 bins x 360 rays