AnalyzeFMRI (version 1.1-16)

xyzt2st: xyzt2st

Description

Extract space and time dimension codes from the one byte xyzt.units field of a NIFTI header file.

Usage

xyzt2st(xyzt.units)

Arguments

xyzt.units

xyzt.units field of a NIFTI header file

Value

A list containing space and time fields.

Bits 0..2 of xyzt.units specify the units of pixdim[2..4] (e.g., spatial units are values 0,1,2,...,7). Bits 3..5 of xyzt.units specify the units of pixdim[5] (e.g., temporal units are multiples of 8: 0,8,16,24,32,40,48,56).

This compression of 2 distinct concepts into 1 byte is due to the limited space available in the 348 byte ANALYZE 7.5 header.

Some NIFTI codes: 0 (unspecified units), 1 (meters), 2 (millimeters), 3 (micrometers), 8 (seconds), 16 (milliseconds), 24 (microseconds), 32 (Hertz), 40 (ppm, part per million) and 48 (radians per second).

See Also

st2xyzt

Examples

# NOT RUN {
xyzt.units <- f.read.header(system.file("example-nifti.hdr", package="AnalyzeFMRI"))$xyzt.units
xyzt2st(xyzt.units)
# }