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

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

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

• summary.scan()

• get_elevation_angles()

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