AFNI program: 3dNLfim
Output of -help
Program: 3dNLfim
Author: B. Douglas Ward
Initial Release: 19 June 1997
Latest Revision: 07 May 2003
This program calculates a nonlinear regression for each voxel of the
input AFNI 3d+time data set. The nonlinear regression is calculated
by means of a least squares fit to the signal plus noise models which
are specified by the user.
Usage:
3dNLfim
-input fname fname = filename of 3d + time data file for input
[-mask mset] Use the 0 sub-brick of dataset 'mset' as a mask
to indicate which voxels to analyze (a sub-brick
selector is allowed) [default = use all voxels]
[-ignore num] num = skip this number of initial images in the
time series for regresion analysis; default = 3
[-inTR] set delt = TR of the input 3d+time dataset
[The default is to compute with delt = 1.0 ]
[The model functions are calculated using a
time grid of: 0, delt, 2*delt, 3*delt, ... ]
[-time fname] fname = ASCII file containing each time point
in the time series. Defaults to even spacing
given by TR (this option overrides -inTR).
-signal slabel slabel = name of (non-linear) signal model
-noise nlabel nlabel = name of (linear) noise model
-sconstr k c d constraints for kth signal parameter:
c <= gs[k] <= d
-nconstr k c d constraints for kth noise parameter:
c+b[k] <= gn[k] <= d+b[k]
[-nabs] use absolute constraints for noise parameters:
c <= gn[k] <= d
[-nrand n] n = number of random test points
[-nbest b] b = find opt. soln. for b best test points
[-rmsmin r] r = minimum rms error to reject reduced model
[-fdisp fval] display (to screen) results for those voxels
whose f-statistic is > fval
The following commands generate individual AFNI 2 sub-brick datasets:
[-freg fname] perform f-test for significance of the regression;
output 'fift' is written to prefix filename fname
[-frsqr fname] calculate R^2 (coef. of multiple determination);
store along with f-test for regression;
output 'fift' is written to prefix filename fname
[-fsmax fname] estimate signed maximum of signal; store along
with f-test for regression; output 'fift' is
written to prefix filename fname
[-ftmax fname] estimate time of signed maximum; store along
with f-test for regression; output 'fift' is
written to prefix filename fname
[-fpsmax fname] calculate (signed) maximum percentage change of
signal from baseline; output 'fift' is
written to prefix filename fname
[-farea fname] calculate area between signal and baseline; store
with f-test for regression; output 'fift' is
written to prefix filename fname
[-fparea fname] percentage area of signal relative to baseline;
store with f-test for regression; output 'fift'
is written to prefix filename fname
[-fscoef k fname] estimate kth signal parameter gs[k]; store along
with f-test for regression; output 'fift' is
written to prefix filename fname
[-fncoef k fname] estimate kth noise parameter gn[k]; store along
with f-test for regression; output 'fift' is
written to prefix filename fname
[-tscoef k fname] perform t-test for significance of the kth signal
parameter gs[k]; output 'fitt' is written
to prefix filename fname
[-tncoef k fname] perform t-test for significance of the kth noise
parameter gn[k]; output 'fitt' is written
to prefix filename fname
The following commands generate one AFNI 'bucket' type dataset:
[-bucket n prefixname] create one AFNI 'bucket' dataset containing
n sub-bricks; n=0 creates default output;
output 'bucket' is written to prefixname
The mth sub-brick will contain:
[-brick m scoef k label] kth signal parameter regression coefficient
[-brick m ncoef k label] kth noise parameter regression coefficient
[-brick m tmax label] time at max. abs. value of signal
[-brick m smax label] signed max. value of signal
[-brick m psmax label] signed max. value of signal as percent
above baseline level
[-brick m area label] area between signal and baseline
[-brick m parea label] signed area between signal and baseline
as percent of baseline area
[-brick m tscoef k label] t-stat for kth signal parameter coefficient
[-brick m tncoef k label] t-stat for kth noise parameter coefficient
[-brick m resid label] std. dev. of the full model fit residuals
[-brick m rsqr label] R^2 (coefficient of multiple determination)
[-brick m fstat label] F-stat for significance of the regression
The following commands write the time series fit for each voxel
to an AFNI 3d+time dataset:
[-sfit fname] fname = prefix for output 3d+time signal model fit
[-snfit fname] fname = prefix for output 3d+time signal+noise fit
-jobs J Run the program with 'J' jobs (sub-processes).
On a multi-CPU machine, this can speed the
program up considerably. On a single CPU
machine, using this option is silly.
J should be a number from 1 up to the
number of CPU sharing memory on the system.
J=1 is normal (single process) operation.
The maximum allowed value of J is 32.
* For more information on parallelizing, see
http://afni.nimh.nih.gov/afni/doc/misc/parallize.html
* Use -mask to get more speed; cf. 3dAutomask.
This page generated on
Tue Aug 3 16:42:45 EDT 2004