xyz2ijk: xyz2ijk

In AnalyzeFMRI: Functions for Analysis of fMRI Datasets Stored in the ANALYZE or NIFTI Format

Description

This function maps from some real world (x,y,z) positions in space into data coordinates (e.g. column i, row j, slice k). These original positions could relate to Talairach-Tournoux (T&T) space, MNI space, or patient-based scanner coordinates.

Usage

xyz2ijk(xyz=c(1,1,1),method=2,L)

Arguments

xyz	matrix. Each column of xyz should contain a voxel real world index coordinates (x,y,z) to be mapped to its (i,j,k) voxel index coordinates in the dataset
method	1 (qform.code=sform.code=0),2 (qform.code>0, rigid transformation) or 3 (sform.code>0, affine transformation).
L	header list of a NIFTI file

Details

See help page of function ijk2xyz().

Value

A list containing the matrix xyz of the positions of the points specified in ijk.

See Also

ijk2xyz Q2R R2Q

Examples

L <- f.read.header(system.file("example-nifti.hdr",
package="AnalyzeFMRI"))
xyz <- matrix(c(1,1,1,2,3,7),byrow=FALSE,nrow=3)
xyz2ijk(xyz=xyz,method=2,L)

Example output

Loading required package: R.matlab
R.matlab v3.6.2 (2018-09-26) successfully loaded. See ?R.matlab for help.

Attaching package: ‘R.matlab’

The following objects are masked from ‘package:base’:

    getOption, isOpen

Loading required package: fastICA
Loading required package: tcltk
Loading required package: tkrplot
Warning messages:
1: no DISPLAY variable so Tk is not available 
2: loading Rplot failed 
$ijk
         [,1]     [,2]
[1,] 26.66667 26.33333
[2,] 38.33333 39.00000
[3,] 18.33333 20.33333

AnalyzeFMRI documentation built on Oct. 5, 2021, 5:06 p.m.