Using AFNI Interactively
Start AFNI from the command line
 afni reads datasets from the current directory
 afni dir1 dir2 É reads datasets from directories listed
 afni -R  reads datasets from the current directory and from all directories below it
AFNI reads the file named .afnirc from you home directory, if it is present
This file is used to change many of the defaults (cf. File README.environment)

"Miscellaneous features of the AFNI..."
Miscellaneous features of the AFNI controller window:
 xyz-coordinate display in upper left corner shows current focus location
By default, the coordinates are in RAI order (from the DICOM standard):
 x  =  Right (negative) to Left (positive)
 y  =  Anterior (negative) to Posterior (positive)
 z  =  Inferior (negative) to Superior (positive)
This display order can be changed to the neuroscience imaging order LPI:
 x  =  Left (negative) to Right (positive)
 y  =  Posterior (negative) to Anterior (positive)
 z  =  Inferior (negative) to Superior (positive)
The [Bhelp] button: when pressed, the cursor changes to a hand shape; use it to click on any AFNI button and you will get a small help popup
AFNI also has ÔhintsÕ (AKA ÔtooltipsÕ)
Press the [New] button to open a new AFNI controller
Used to look at more than one dataset at a time
 [Define Datamode] Þ [Lock] can be used to lock controllers together by coordinates
All viewing windows within a controller are always locked together
Press the [Views] button to close/open the control panel at right

"Press the [done]"
Press the [done] button twice within 5 seconds to exit AFNI
The first button press changes ÔdoneÕ to ÔDONEÕ
Fail to press second time in 5 seconds and it changes back to ÔdoneÕ
Whatever you do, donÕt press a mouse button in the blank area to the right of [done]
I wonÕt be responsible for the consequences
The [Switch] buttons let you control which datasets are being viewed
 [Switch Session] controls which directory datasets are drawn from
 [Switch Underlay] control the background (grayscale) dataset --- anat dataset usually goes here
Current anat dataset determines the resolution of and 3D region covered by image viewers
 [Switch Overlay] controls the overlay (color) dataset --- func dataset usually goes here
Func datasets will be interpolated -- if needed -- to anat resolution, and flipped -- if needed -- to anat orientation
Current datasets are named in AFNI controller titlebar

"Touring the Image Viewer"
Touring the Image Viewer

"Crosshairs show the current focus..."
Crosshairs show the current focus location
Also show the cut planes for the other image viewers
When using image montage, other viewers show multiple crosshairs
Can control crosshair color and gap size from main AFNI controller
Slider below image lets you move between slices
Left-click and drag ÔthumbÕ to move past many slices
Left-click ahead or behind thumb to move 1 image at a time
Hold click down to scroll continuously through slices
Middle-click in ÔtroughÕ to jump quickly to a given location
Vertical intensity bar to right of image shows mapping from numbers stored in image to colors shown on screen
Bottom of intensity bar corresponds to smallest numbers displayed
Top corresponds to largest numbers displayed
Smallest-to-largest display range is selected from [Disp] control panel
or from hidden popup menu on intensity bar
All image viewers from all AFNI controllers use the same intensity bar
unless AFNI is started with the -uniq command line option, in which case each AFNI controllerÕs viewers have independent intensity bars
but all image viewers from the same controller always share the same intensity bar

"Buttons at right"
Buttons at right
 [Colr] changes grayscale to color spectrum, and back
 [Swap] swaps top of intensity bar with bottom
 [Norm] returns the intensity bar to normal (after you mess it up)
 [c] controls contrast
 [b] controls brightness
Useful combination  [c] 5 2-3 times,  [b] 6 2-3 times
 [R] rotates the intensity bar (useless, but very fun)
 [g] changes the gamma factor (nonlinearity) for the intensity bar
 [I] changes the size of the image in the window
 [9] changes the opacity of the color overlay
This control only present for X11 TrueColor displays
At bottom right, the arrowpad controls the crosshairs
Arrows move 1 pixel in that direction for that window
Sagittal 3 is same as Axial 5
Central button closes and opens crosshair gap
Items on AFNI controller (below xzy display) also alter crosshairs
Can change color, gap size, É

"Buttons along bottom provide various..."
Buttons along bottom provide various services
 [Disp] controls the way images are displayed and saved
Pops up its own control window: most controls change image immediately
 Orientation controls at top allow you to flip image around
 [No Overlay ] lets you turn color overlays off (crosshairs; function)
 [Min-to-Max] Þ intensity bar is data min-to-max
 [2%-to-98%] Þ intensity bar is smallest 2% of data to largest 98%
 [Free Aspect] lets you distort image shape freely
 [Save panel] controls how images are saved to disk:
 All buttons off Þ saved image file contains slice raw data
 [Nsize Save] Þ same, but images are 2N in size
 [PNM Save] Þ images are saved in PPM/PGM format (color/gray)
 [Save to .xxx(s)] Þ saves image(s) to specified format
 [Save One] Þ for saving montage
 [Tran 0D] lets you transform voxel values before display
 [Log10] and [SSqrt] useful for images with extreme values
 [Tran 2D] provides some 2D image filters (underlay only)
 [Median 9] smoothing can be useful for printing images
 [Rowgraphs] lets you graph the voxel values from image rows
 If you want columns, flip the image with [CCW 90]
 [Surfgraph] lets you graph the voxel values in a surface graph

"Three extra imaging processing filters..."
Three extra imaging processing filters are provided at the bottom
 [Sharpen] is sometimes useful for deblurring images
 [Reset] sets controls back to what they were when you opened [Disp]
 [Done] closes this control window
 [Save] lets you save images from viewer to disk files
Warning: Images are saved as sent to the viewer, not as displayed
Means that aspect ratio of saved image may be wrong (non-square pixels)
Can fix this with [Define Datamode] Þ [Warp Anat on Demand]
 [Save:bkg] means it will save the background image data itself, whatever the format it may be in (bytes, shorts, floats, complex numbers, RGB byte triples)
 [Save:pnm] means it will save the displayed image in PNM format
PPM for color, PGM for gray-only images
You might have to convert this to some other format
See AFNI FAQ #57 for instructions on image format conversion
 [Sav1:xxx] means it will save the entire Montage in format ÒxxxÓ
This is the only way to save a Montage layout (within AFNI)
 [Save] options will only save single slice images (one or more)
 [Save.xxx] means it will save the image in the ÒxxxÓ format
 You can also set this using the hidden right-click popup on the [Save] Button
Formats depend on presence of image conversion programs on your system

"After you press [Save..."
After you press [Save], then it asks for a filename prefix
Except for [Sav1.xxx], it then asks for ÔfromÕ and ÔtoÕ slice indexes
 You can save many images this way
 Filenames are like are like prefix.0037.ppm, for slice #37, ppm format
 [Sav1.xxx] immediately saves its one file after prefix is entered
 [Mont] lets you display a rectangular layout of images (i.e., montage)
Pops up its own little control window
Controls at top do nothing until an action is selected at bottom
 [Across] and [Down] determine number of sub-images shown
 [Spacing] determines how far apart the selected slices are
Every nth slice, for n = 1, 2, É
Multiple crosshairs in other image viewers will show montage slices
 [Border] lets you put some blank pixels between sub-images
 [Color] lets you choose the color of the border pixels
At the bottom, the action controls cause something to happen:
 [Quit] closes the Montage control window
 [1x1] changes Across and Down back to 1
 [Draw] actually causes the montage to be drawn
 [Set] ó [Draw] then [Quit]

"[Rec]"
 [Rec] lets you record images for later Save-ing
So you can build a sequence of images from any set of AFNI controls
Change color maps, functional thresholds, datasets, É
Then save them to disk for animation, etc.
If Unix programs whirlgif and/or gifsicle are installed on your system, AFNI can write GIF animations directly (e.g., for fun Web pages)
If program mpeg_encode is installed, AFNI can write MPEG-1 animations
Source code for these free programs is included with AFNI source code
 [Rec] button pops down a menu that sets the record mode
 [Off] Þ recording is off
 [Next One] Þ next image displayed is recorded, then goes back to [Off]
 [Stay On] Þ record each image when displayed
Controls below the line determine where in the recording sequence the saved images will be stored
Recorded images go into a new image viewer, with its own controls
Its slider moves between recorded images
 [Kill] will delete an image from the recorded sequence
 [Save] will save record images
Right-click on [Save] to bring up menu of format options
 [Done] to close the recorded image viewer

"Hidden image popup menu (..."
Hidden image popup menu (using Button 3 or right-click)
 [Jumpback] lets you jump the focus position back to its last place
For when you click in the wrong place and get lost
 [Jump to (xyz)] lets you enter xyz-coordinates (in mm), and then the focus position will jump there
External program 3dclust can generate xyz coordinates of interest
Once you have +tlrc dataset, can jump to regions from Talairach atlas
 [Jump to (ijk)] lets you jump to a particular voxel index location
 [Image display] lets you turn control widgets on and off
Can unclutter screen a little
Useful if you want to make a screenshot
Hidden intensity bar popup menu
 [Choose Display Range] lets you pick the range of numbers that are mapped to intensity bar colors
Normally, each image is mapped to colors separately when it is displayed
Using Min-to-Max or 2%-to-98% from [Disp]
If you want each image to be mapped the same, then must give bottom-to-top values via this menu item (separate them with spaces)
If you set third (optional) input ÔztopÕ to 1, values above ÔtopÕ are set to 0
To restore normal auto-mapping, set ÔbotÕ and ÔtopÕ both to 0

"[Choose Zero Color]"
 [Choose Zero Color] lets you choose the color that is displayed for voxel values that are exactly 0
Can be useful for filling in regions that were set to 0 by some program
For example, values below ÔbotÕ from Choose Display Range (and above ÔtopÕ if ÔztopÕ was set to 1)
Choose the ÔnoneÕ color to return to normal display
 [Choose Flatten Range] is used to control the Flatten filter from the [Disp] control window
This is almost useless --- donÕt bother to try it
 [Choose Sharpen Factor] is used to control the Sharpen filter from the [Disp] control window
Larger values mean more sharpening (and more image graininess)
 [Plot Overlay Plots] turns overlay graphs on and off
In future, will control overlay of cortical surface geometry
This feature is experimental now, and not documented
 [Label] and [Size] controls display of slice coordinate overlay

"Touring the Graph Viewer"
Touring the Graph Viewer

"Graph viewer takes voxel values..."
Graph viewer takes voxel values from same dataset as image viewer
If dataset has only 1 sub-brick, graph viewer only shows numbers
To look at images from one dataset locked to graphs from another dataset, must use 2 AFNI controllers and [Define Datamode] Þ [Lock] on AFNI control panel
If graph and image viewer in same slice orientation are both open, crosshairs in image window change to show a box containing dataset voxels being graphed
Central sub-graph (current focus location) is outlined in yellow
Current time index is marked with small red diamond
Left-clicking in a non-central sub-graph moves that location to focus
Left-clicking in central sub-graph moves time index to that point
Can also use [Index] control in AFNI controller
Right-clicking in any sub-graph pops up some statistics of its data
Left-clicking in icon (lower left corner) causes icon and menu buttons to disappear
Useful if you want to do a screenshot to save window
Left-clicking in same place will bring icon and buttons back

"[Opt]"
 [Opt] menu buttons let you control how graphs appear
Many items have keyboard shortcuts
Make sure you are typing in the correct window!
 [Scale] changes scale of graphs
Mapping from voxel values to screen pixels
 Down [ - ] shrinks graphs vertically; Up [ + ] expands them
 Auto [ a ] makes AFNI pick a nice scale factor
 [Choose] lets you pick exact scale factor
Can choose positive values = pix/datum or negative = datum/pix
pix/datum = number of screen pixels for each change of 1 in data
datum/pix = size of change in data for each screen pixel
Current scale factor is shown below graphs
Scale factor does not change when you resize graph,change matrix, etc.
You usually have to auto-scale [ a ] afterwards
 [Matrix] changes number of sub-graphs
 Down [ m ] and Up [ M ] decrease and increase number
 [Choose] lets you pick number exactly
Alternative: keyboard [ N ], type number, then [ Enter ] key
Range of allowable matrix size is 1..21

"[Grid]"
 [Grid] lets you change spacing of vertical grid lines
 Useful for showing regular timing interval (e.g., task timing)
 Down [ g ] and Up [ G ] decrease and increase spacing
 [Choose] lets you pick number exactly
 Current grid spacing is shown below graphs
 [Pin Num] lets you pick the horizontal length of the sub-graph
Default length is number of sub-bricks in dataset
Make it longer Þ graphs end before window
Make it shorter Þ graphs are truncated
Useful when switching between datasets of different lengths
Set this to 0 to get back to default operation
Current number of time points is shown below graphs
 HorZ [ h ] will put in a dashed line at the y = 0 level in sub-graphs
Only useful if data range spans negative and positive values!
 [Slice] lets you change slices
 Down [ z ] and Up [ Z ] move one slice
 Can also choose slice directly from menu
 Current voxel indexes are shown below graphs
Corresponds to [Voxel Coords?] Display in AFNI controller

"[Colors,"
 [Colors, Etc.] lets you alter the colors/lines used for drawing
Lines used for sub-graph frame boxes, grid lines, data graphs, FIM orts/ideals, and double plots can have color changes and be made thicker
Grid color is also used to highlight central sub-graph
Can choose to graph curves as lines, points, or both together
Can change color of background and text
Can change gap between sub-graph boxes
 Baseline [ b ] changes how the sub-graphs are plotted
All sub-graphs have same scale factor, to convert values into vertical pixels
Baseline is value that gets plotted to bottom of sub-graph
Individual: all sub-graphs have different baselines
Baseline = smallest value in each displayed time series
This can be confusing; same vertical location doesnÕt mean same value
Shown below graphs as Base: separate
Common: all sub-graphs shown at any one time get same baseline
Baseline = smallest value in all displayed time series
Shown below graphs as Base: common
Usually need to rescale [ a ] after changing baseline
Global: all sub-graphs get same baseline even when spatial position changes
Set from [Baseline] Þ [Set Global] menu item
Default global level is smallest value in entire dataset

"Range of central sub-graph..."
Range of central sub-graph is shown at left of graph region
Central bottom (baseline) value is shown at lower left
Upper left shows value at top of central sub-graph box
Number in [brackets] shows data range of one sub-graph boxÕs height
If baselines are separate, bot/top values only apply to central sub-graph
 Show text? [ t ] allows you to see text display of values instead of graphs
 Save PNM [ S ] lets you save a snapshot of window to a PNM image file
 Write Center [ w ] lets you write data from central sub-graph to a file
File is in ASCII format Þ can be imported into other programs
Filename is of form xxx_yyy_zzz.suffix.1D (using voxel indexes)
Suffix is chosen using [Set ÔwÕ suffix] button
 [Tran 0D] and [Tran 1D] let you transform the data before graphing
 [Log10] and [SSqrt] useful for images with extreme values
 [Median3] and [OSfilt3] are for are for smoothing time series
 Other choices are functions controlled by/from plugins
 [Double Plot] lets you plot output of [Tran 1D] and original data together
 Color of transformed data from [Dplot] on the [Colors, Etc.] menu
 [Dataset#2] transformation lets you plot two datasets together

"[X-axis]"
 [X-axis] menu lets you  choose how graph x-axis is chosen
Default: x is linear in time
Can instead choose x from a .1D format file from disk
Useful only in very limited circumstances
 Done [ q ] closes the graph viewer window
 Keystrokes in graphs that have no menu items are:
 [ < ] moves time index down by 1
 [ > ] moves time index up by 1
 [ 1 ] moves time index to beginning (time index = 0)
 [ l ] moves time index to end
 [ L ] turns off/on the AFNI logo in the corner
 [FIM] menu controls interactive functional image calculations
Not documented here; see ÔEducational materialsÕ pages at AFNI Web site

"Brief Tour of the Functional..."
Brief Tour of the Functional Color Overlay Controls
Open with [Define Overlay] button on AFNI controller

AFNI Plugins
Plugins are modules that attach themselves to AFNI and add some interactive capabilities to the GUI program
There is a (somewhat dated) manual for writing plugins
Useful plugins:
 3D Registration:
Provides a GUI control for time series registration (same as 3dvolreg)
 Dataset Copy:
Copy a dataset (useful as a start for ROI drawing)
 Dataset NOTES:
  Add arbitrary text notes to a dataset header
 Draw Dataset, Gyrus Finder:
Draw regions-of-interest (ROIs) on 2D slices
 Histogram:
Graph the histogram of a sub-brick, or some parts of it
 Deconvolution, Nlfit & Nlerr:
Do linear and nonlinear regression interactively on the dataset time series  being displayed in a graph viewer

"Render Dataset:"
Render Dataset:  Volume rendering with functional overlays

Using AFNI in Batch Mode
Batch mode programs are run by typing commands directly to the computer, or by putting these commands into text files (scripts) and later executing them
Advantages of batch mode (over graphical user interface)
Can process new datasets exactly the same way as previous ones
Can link together a series of programs to produce custom results
Programs that take a long time to operate are easier to Ôfire and forgetÕ from a script than if they had a GUI
ItÕs easier to write a batch mode program
Disadvantages of batch mode
Requires typing, rather than pointing-and-clicking
Requires learning/remembering how a program works all at once, rather than (re)discovering it through a kinder gentler interface
Many younger (born after 1970) researchers have virtually no experience with a command line interface, or anything like it
Many significant AFNI capabilities are only available in batch mode programs
This is especially true of functions that combine data from multiple datasets to produce new datasets

"The 3d*"
The 3d* series of programs (generally) take as input one or more AFNI datasets, and produce as output one (or more) new AFNI datasets
Time series activation analysis programs:
3dfim, 3dfim+, 3ddelay
Variations on ÔclassicalÕ correlation analysis of each voxelÕs time series with a single reference (ideal) waveform
3dDeconvolve:
Multiple linear regression and/or linear deconvolution to fit each voxelÕs time series to a mulit-dimensional signal model (similar models are found in SPM)
3dNLfim:
Nonlinear regression to fit each voxelÕs time series to an arbitrary functional model provided by the user
Time series utility programs:
3dFourier:
Fourier domain filtering voxels time series
3dTcorrelate:
Compute correlation coefficient of 2 datasets, voxel-by-voxel
3dTsmooth:
Smooth voxel time series

"3dTqual,"
3dTqual, 3dToutcount:
Examine voxel time series for statistical ÔoutliersÕ
3dTcat:
Shift voxel time series to a common temporal region
3dTstat:
Basic statistics on voxel time series
3dvolreg:
Volume registration to suppress motion artifacts, and to align same-subject data from different scanning sessions
Multi-dataset statistical operations:
3dttest:
Voxel-by-voxel t-tests
3dANOVA, 3dANOVA2, 3dANOVA3:
1-, 2-, and 3-way voxel-by-voxel ANOVAs, including random effects and nested models
3dFriedman:
Voxel-by-voxel nonparametric statistical tests analogous to ANOVAs
3dRegAna:
General linear regression models and tests derived therefrom

"Miscellaneous operations on datasets:"
Miscellaneous operations on datasets:
3dAnatNudge:
Try to align high-resolution anatomical volume with low-resolution EPI volume
3dClipLevel:
Find the voxel value to threshold EPI volume so as to remove most of the non-brain tissue
3dIntracranial:
Strip the scalp and other non-brain tissue from a high-resolution T1-weighted anatomical volume
3dMean:
Compute the mean of a collection of datasets, voxel-by-voxel
3dmaskdump, 3dmaskave, 3dROIstats:
Extract values from datasets and write to ASCII files
3dUndump:
Take values from ASCII files and write into a dataset
3dmerge:
Lots of options to edit datasets and combine them in multifarious and nefarious ways
3dZeropad, 3dZcutup, 3dZcat, 3dZregrid:
Utilities to add/subtract/resample datasets in the slice (z) direction

"3daxialize:"
3daxialize:
Re-write a dataset in a new slice direction
3dcalc:
General purpose voxel-by-voxel dataset calculator
3dresample, 3dfractionize:
Resample a binary mask dataset from one resolution to another
3drotate:
Rotate a dataset to a new orientation in space
3dpc:
Extract principal components from a collection of datasets
3dWinsor:
Spatially filter a T1-weighted anatomical dataset to reduce noise and make the gray-white matter boundary a little more distinct
3dclust:
Find clusters of activated voxels and print out statistics about them
3dExtrema:
Find local extrema (maxima or minima) in a dataset --- intended for functional activation maps