This is a collection of MATLAB utilities developed by Kendrick Kay (kendrick@post.harvard.edu, http://kendrickkay.net). The philosophy of the code is to maximize power (i.e. the ability to perform many different things) and generality (i.e. the ability to re-use code for many different situations). Let me know if you have comments. Some of the code uses random-number generation, so it is recommended that you have something like rand('state',sum(100*clock)); randn('state',sum(100*clock)); in your MATLAB startup.m file. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% CHANGE HISTORY Below we document major code changes. Minor code changes and tweaks that have no significant impact are not mentioned here (e.g. things like cosmetic adjustments, code speed-ups, making functions more general by adding optional input arguments, fixing bugs that would have result in code crashes, etc.). Major changes include things that make the code backwards-incompatible and things that change actual analysis results. History of major code changes: 2019/09/23 - major bug fix to matchfiles.m. previously the order of cell vector elements was not respected. now order is respected. 2018/12/22 - matchfiles.m now RETURNS any duplicate filename matches. This changes past behavior. 2018/12/22 - to resolve function naming conflicts, we have done the following: (1) completely removed the function called count.m, (2) completely removed the function called discretize.m, (3) renamed the function strsplit.m to strsplitalt.m 2014/07/31 - in constructpolynomialmatrix.m, we now make the polynomials orthogonal and unit length. this changes previous behavior! 2013/11/18 - use a smoother canonical HRF in getcanonicalhrf.m 2013/09/07 - fix bug in fitnonlinearmodel (if polynomials or extra regressors were used in multiple runs, then they were not getting fit properly). 2013/08/18 - in makedirid.m, occurrences of '-' are now replaced with '_' 2013/08/18 - in projectionmatrix.m, in the cases of empty <X>, we now return 1 instead of []. 2012/06/14 - in constructpolynomialmatrix2d.m and constructpolynomialmatrix3d.m, we now sort the char representation of the basis functions. the reason is that previously, different machine architectures would give different orders for the basis functions. this is horrible, as it means that different machines would have different parameter orders. the fix (which hopefully is robust) is to sort the basis function character-wise, explicitly. please be aware of this change! 2012/01/23 - in viewimage.m, no longer make a new window and no longer return the figure number 2011/12/10 - in applymultiscalegaussianfilters.m, we now make the default mode to be 0 (center on pixels). this changes previous behavior. 2011/10/13 - in pton.m, now always generate a CLUT at 8-bit (256 rows) 2011/10/09 - in fitprfstatic.m, <outputfcn> no longer accepts all those special inputs; it is now a usual OutputFcn. 2011/09/22 - add required argument to copyxform_nii 2011/09/16 - the default behavior in dicomloaddir has changed. we now match all files and perform numerical sorting. 2011/09/13 - make the yellow color in cmapdistinct slightly darker 2011/08/30 - in fitprf.m, we now use stepwise fitting in the nonlinear case (i.e. <mode> is not 0 nor {0}). this should improve the avoidance of local minima problems, but does change previous behavior!! 2011/07/11 - in dicomloaddir.m, we now have the extra assumption that all files are DICOM files when <filenameformat> is supplied 2011/07/01 - we now use nanmedian and nanmean in calcmdse.m 2011/06/29 - in printnice.m, we now temporarily change PaperPositionMode to auto before printing. this should make rasterized image output better (in terms of getting the resolution right). 2011/06/27 - in olsmatrix.m, we now explicitly handle the case of all-zero regressors. previously, NaNs would result. now, we just ensure that these all-zero regressors get returned a zero weight. 2011/05/26 - in scatterb.m, we weren't drawing the main line. weird. we have changed it now to do the right thing. this modifies old behavior. 2011/04/26 - in constructorientationfilter.m, fixed major bug. orientation was interpreted wrongly and filters were peaked at the wrong orientation. 2011/04/02 - in matchfiles.m, time-sorting behavior did not work (it would always give alphabetical order). fixed now. 2011/03/09 - in defineellipse3d.m, we now show a maximum of 25 slices. 2011/03/08 - for alignvolumedata.m, make much faster (using ba_interp3), take less memory, remove spline interpolation option, ensure that the alignvolumedata_auto_outputfcn runs at optimization completion. 2011/03/08 - smoothvolumes handles NaNs intelligently now. this changes old behavior. 2011/03/06 - complete revamp of calcnoiseceiling.m. 2011/02/24 - in matchfiles.m, we now properly match patterns that have spaces in them (since we now escape the spaces using \). previous behavior was to simply not match those cases. 2011/02/02 - in zerodiv.m, in the case that y is not a scalar and wantcaution is set to 0, we were allowing division by 0 to result in Inf and *notreplaced with val as desired. big mistake. we have now fixed this. utilities that could have used this buggy behavior of zerodiv include calccod, calccorrelation, calcentropy, calcsparseness, calczscore, l1unitlength, unitlength. 2011/01/21 - in matchfiles.m, we explicitly use MATLAB's sort function (for alphabetical ordering) to ensure consistency across platforms. this might change the alphabetical ordering of matches! 2010/01/17 - completely change cmapdistinct.m; leave JVM on by default in runmatlabinbg.pl 2010/01/05 - in scatterline.m, we now attempt to use nanmean and nanstd to allow more cases in. see code for details. 2010/12/27 - in divnorm.m, we now explicitly handle cases where the numerator is Inf. the goal is to try to keep outputs finite when possible. 2010/12/16 - circlewithin.m changed from binary (all within or not) to a graded response 2010/12/06 - in fitprf.m, change initial seeds for certain basis function cases (in particular, we no longer force weights to 1. it seems that nonlinear fitting can operate successfully even if there is a gain ambiguity) 2010/12/03 - in fitprf.m, changed the form of the input <hrfnormfun> (this requires changes to how the function is called); 2010/12/02 - in fitprf.m and fitprfmulti.m, a number of significant changes: [<ar> input has been deprecated; <arfile> input has been removed; the <meanint>,<driftstd>,<signalrms>,<noiserms> outputs have been removed (I no longer think they are useful); fix bug --- the signal and drift outputs were not getting assigned in the re-do calls of the [A B C] case of <maxiter>]; removed evaluateprfmodel.m 2010/11/24 - remove hrfsample1, remove hrfsample2 [these were obsolete] 2010/11/23 - in calccod.m, change the output range to percentages (R^2). thus the range is (-Inf,100]. also, we removed the <wantr> input since it was dumb. also, please note that many functions that rely on calccod.m inherit this change to percentages. thus, this was a big global code change. 2010/10/24 - we now impose assumption in rowfun.m that each result has the same size 2010/10/22 - in fitprf.m, fix bug concerning exitflag and maxiters. if there were multiple resamplings, then we were checking only the last exitflag when deciding to re-do the fitting process. now, we do the right thing --- we check to see if any of the resamplings stopped because they reached the max number of iterations. 2010/10/22 - in fitprf.m, change initial seed for prfmodel and hrfmodel basis functions to 0! 2010/10/09 - remove showmulticlass.m 2010/10/05 - fixed bugs in sortnumerical.m. previous calls may have crashed or failed to produce correct answer. 2010/10/02 - fot defineellipse3d.m, change initial visualization state 2010/10/02 - for fitgaussian3d.m, new default initial seed. more liberal tolerance. explicitly guard against nans. 2010/10/02 - in defineellipse3d.m, the fitted Gaussian no longer has a dc fixed to 0 but has an exponent now. 2010/09/27 - zerodiv.m no longer issues warnings when not <wantcaution> 2010/08/25 - explicitly put /home/knk in queuedaemon. this should be revisited eventually... 2010/08/25 - for outputfcnplot, we revamped this function [hack out ratio check; hack out <restol>; hack out NaN case for <numiters>] 2010/08/11 - queuedaemon, runme have been revamped and are not backwards-compatible. 2010/06/22 - unix_wrapper.m now reports status and result to the command window. 2010/06/15 - start using calccod.m instead of calccorrelation.m where appropriate (see subspaceapprox, fitprf, fitprfmulti, fitgabor2d, fitorientedgaussian2d, fitrbf2d) %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% SUMMARY OF FUNCTIONS Here is a short summary of each function so that you can do a simple text search to see if there is a function that already does what you need. matrix/ addvectors - add vectors of unequal sizes blob - sum over successive groups along a certain dimension of a matrix catcell - concatenate elements of a cell matrix catmatrix - concatenate matrices (possibly unequal in size) cellfunfirst - apply function to first element of a cell matrix (or the matrix itself) cropvalidvolume - extract a subvolume of a matrix based on valid values equalizematrixdimensions - make two matrices the same dimensions by expanding fillout - repeat a matrix to fill a desired size filterout - remove elements of a matrix according to a simple boolean operation flatten - make into a row vector fillmatrix - take a vector and fill a matrix with it flipdims - flip some dimensions of a matrix insertelt - insert element(s) in a vector placematrix - place a 2D matrix inside another 2D matrix at an arbitrary position placematrix2 - place a matrix inside another matrix placematrixmulti - repeatedly randomly place a 2D matrix inside another 2D matrix reshape2D - get into 2D for convenient manipulation reshape2D_undo - undo what reshape2D does reshapesquare - reshape a vector into a square matrix rotatematrix - 2D rotation for an arbitrary matrix sizefull - get size of a matrix for a certain number of dimensions splitmatrix - take slices of a matrix and put them into a cell vector splitruns - find runs of non-NaN numbers in a vector squeezedim - remove a specific dimension that has only one element squish - squish together the first n dimensions of a matrix upsamplematrix - change the dimensionality of a matrix by upsampling vflatten - make into a column vector indexing/ calcposition - calculate the position of elements relative to a list chunking - split a vector into chunks firstel - return first element of a matrix firstelc - return first element of a cell matrix indexall - return an indexing helper for cell vectors lastel - return last element of a matrix linspacecircular - get equally spaced points in a circular domain linspacefixeddiff - get equally spaced points given a fixed difference linspacepixels - get equally spaced points that can be treated as centers of pixels matrixindex - return different slices through a matrix based on an indexing matrix permutedim - shuffle a matrix along a certain dimension or globally picksubset - return a random subset of the elements in a matrix removerepeats - get rid of runs of consecutive items resamplingindices - get indices corresponding to the process of resampling slicematrix - return a slice from a matrix subscript - get elements using a vector or cell vector of indices vectorsplit - split a vector into chunks programming/ allocatememory - force allocation of a certain amount of memory (to induce swapping) alwaysone - always return 1 alwayszero - always return 0 assignseparatevars - split a matrix and assign it to multiple variables assigntobaseworkspace - assign all variables to the base workspace checkmemoryworkspace - figure how much memory is being used in the caller's workspace checkpathconflicts - check for .m file conflicts choose - functional form of if-else copymatrix - make a copy of a matrix with a subscript assignment on-the-fly consolidatemat - consolidate results from multiple .mat files into a single .mat file consolidatematdir - consolidate results from .mat files in a directory decodenum - undo encodenum.m defaultoptimset - return a default optimset options structure encapsulate - evaluate a function at multiple values and encapsulate results into a cell vector encodenum - encode a number as a string of uppercase letters enforcenan - set cases with all 0 to NaN evalme - evaluate multi-line input in the MATLAB workspace gethostname - get the hostname getpid - get the process ID for this instance of MATLAB gettimestring - return the current date/time as a simple integer string GPUconv - convert to GPU format GPUok - return whether we should try to use the GPU gunziptemp - gunzip a file on the fly identity - return an argument unchanged infiniteloop - do nothing forever inputmulti - take multi-line string input from stdin isfinitenum - evaluate whether each element is finite and numeric isint - evaluate whether each element is an integer isrowvector - evaluate whether matrix is 1 x n (where n >= 0) maketempdir - make a new empty temporary directory and return the path to it. mergestructs - merge one struct into another mkdirquiet - make a directory, suppressing warnings mtimesmulti - multiply arguments together passmulti - pass multiple arguments to a function from a cell vector pause2 - pause but also return an output playalarm - play an alarm to get the user's attention plusmulti - add arguments together processchunks - perform an operation on successive chunks of a big matrix to save on memory usage promptforfile - get a .mat file name from the user repeatuntil - call a function until a condition is satisfied reportmemoryandtime - use a warning to report the current memory usage and the current time rmdirquiet - remove a file or directory, suppressing warnings rowfun - apply a function to each row of a 2D matrix runmatlabinbg.pl - run MATLAB in the background for a single function/script call sanitycheck - print out some fprintf statements about values in a matrix saveemptymat - save an empty .mat file setrandstate - induce randomness by (randomly) setting the seed of rand and randn sgerun2 - run MATLAB code using the Sun Grid Engine (SGE) statusdots - write out dots (.) indicating progress of code execution subsetfun - apply a function to successive subsets of a vector swap - swap two arguments unix_wrapper - a nice wrapper for unix.m string/ cell2str - convert 2D cell matrix into string representation cell2str2 - convert cell vector of strings into a single string that names each string fixstr - fix string for use with MATLAB's figure functions makedirid - return a string with elements of a path joined with '_' makeletters - generate a cell vector of letter characters mat2cellstr - convert a matrix of numbers into a cell matrix of strings matchword - return the first word found in a string randomword - generate a random word consisting of capital letters sortnumerical - sort a cell vector of strings according to trailing integers strsplitalt - split a string based on a pattern io/ absolutepath - return the absolute path to a given file clearexcept - clear all variables except certain variables getextension - get the extension (e.g. '.txt') of a filename loadbinary - load numbers from a binary file loadexcept - load variables from a .mat file, excluding certain variables loadmaybe - load variable from a .mat file, but failing gracefully loadmulti - concatenate or merge a single variable from multiple .mat files loadmulti2 - load multiple variables from one .mat file loadtext - load strings from a text file matchfiles - return strings containing paths to matched files and/or directories multifile - apply a function to multiple files niiload - load specific voxels from NIFTI files containing 4D data raw2dload - load specific columns from binary files containing 2D data savebinary - save numbers to a binary file saveexcept - save all variables to a .mat file, excluding certain variables savetext - save strings to a text file shuffletext - shuffle lines in a text file stripext - remove the extension from a file name stripfile - remove the file name from a string math/ addnoise - add some noise to a matrix allzero - check whether all elements are equal to zero within some tolerance ang2complex - convert angles to unit-magnitude complex numbers chunkfun - apply a function to successive chunks of a vector chunknormalize - subtract mean of successive chunks of a matrix calccod - calculate coefficient of determination (R^2) calccodcell - calccod for cell vectors of matrices calccorrelation - calculate Pearson's correlation coefficient (r) calcmdse - calculate the median and the standard error on the median calcmdsepct - calculate the median and percentiles on bootstraps of the median calcsparseness - calculate sparseness calczscore - convert to z-scores circularavg - average numbers, respecting circularity circulardiff - difference between two values defined in a circular domain circularshiftandsum - take a vector, circularly shift it multiple times, and sum clipoutliers - clip the outliers of a matrix constructpathonsphere - connect points on the unit sphere countinstances - count how many 1s, 2s, etc. are in a matrix divnorm - apply divisive normalization to a matrix matchgain - figure out scalar factor to match one set of data to another meanandse - calculate the mean and standard error meancell - take the mean for data that are split into cell matrices mod2 - like mod.m but return 0 outputs as the modulus itself mod4 - like mod.m but restrict outputs to the range [-modulus/2,modulus/2] mtimescell - do matrix multiplication but with an argument split into a cell vector nanreplace - replace NaNs with a specified value nanreplace2 - replace NaNs with a specified value (alternative mode of operation) nantoclosest - replace NaNs with the nearest valid values negrect - negative-rectify negreplace - replace negative values with a specified value normalizerange - scale to fit within a specific range normalizemax - scale such that max value is 1 posnegrect - positive- and negative-rectify posrect - positive-rectify restrictrange - truncate values to fit within a range robustrange - calculate a robust range of a set of values signedarraypower - take the array power but preserve sign signforce - return +1 for positive or zero elements; -1 for negative elements stdquartile - return something like std but in the percentile sense unitlength - normalize to have unit length (L2-norm is 1) unitlengthfast - normalize to have unit length (L2-norm is 1) l1unitlength - normalize to have unit length (L1-norm is 1) vectorlength - calculate vector length (L2-norm) l1vectorlength - calculate vector length (L1-norm) zerodiv - divide but with special handling for division by zero zeromean - subtract off the mean stats/ applyfiltermultidim - apply filters for the case of images with multiple features bootstrap - apply a function to bootstrap samples drawn from a vector (useful for computing standard error) bootstrapdim - more general version of bootstrap calcconfusionmatrix - calculate a confusion matrix (i.e. covariance, cross-product, etc.) calcentropy - calculate entropy based on a matrix with counts calcggaussianlikelihood - calculate likelihood of a set of points assuming independent generalized Gaussian distributions calcintrinsicdim - calculate number of eigenvectors needed to achieve a certain amount of the variance in a matrix calcmutualinformation - calculate mutual information between two matrices calcmutualinformationcontinuous - calculate mutual information between two matrices in a continuous way calcmvgaussianpdf - calculate multivarate Gaussian probability density function calcnoiseceiling - calculate how well a set of data can be predicted, taking into account the intrinsic noisiness of the data calcoptimalhistbins - calculate the optimum number of bins to use for hist.m calcrbflikelihood - calculate likelihood of a set of points given a collection of RBFs calcrectlikelihood - calculate likelihood of a set of points given a collection of directions (half-squared responses) calcrobustsummary - calculate the median and one-half of the central 68% range calcshrunkencovariance - use shrinkage and cross-validation to obtain more robust estimates of covariance calcsurfaceareanball - calculate surface area of a unit n-ball centerofmass - calculate the center-of-mass of a matrix constructdctmatrix - construct a matrix with DCT-II basis functions in the columns constructdftmatrix - construct a matrix with DFT basis functions in the columns constructfiltersubsample - construct 2D filters according to a subsampling scheme constructfiltertiling - construct filters by tiling a single 2D filter constructnearestpsdcovariance - find the nearest positive semidefinite matrix constructpolynomialmatrix - construct a matrix with polynomials in the columns constructpolynomialmatrix2d - evaluate polynomial basis functions defined in 2D at some locations constructpolynomialmatrix3d - evaluate polynomial basis functions defined in 3D at some locations convertcovariancetocorrelation - convert a covariance matrix to a correlation matrix evaldivnorm - evaluate divisive-normalization function at some values evalgaussian1d - evaluate 1D Gaussian function at some coordinates evalgaussian2d - evaluate 2D Gaussian function at some coordinates evalgaussian2doriented - evaluate 2D Gaussian function (that can be rotated) at some coordinates evalgaussian3d - evaluate 3D Gaussian function at some coordinates evalgeneralizedgaussian - evaluate generalized Gaussian pdf filter2subsample - apply filter2 and then subsample the result findlocal - find points that are close to a given point findtailthreshold - determine a threshold for a distribution of data using a GMM with 2 Gaussians fit2dpolynomialmodel - use polynomial basis functions to fit a surface defined in 2D, allowing scale factor for different cases fit3dpolynomialmodel - use polynomial basis functions to fit a surface defined in 3D, allowing scale factor for different cases fit3dpolynomialmodel2 - use polynomial basis functions to fit a surface defined in 3D, allowing DC offset for different cases fitdivnorm - fit divisive-normalization function fitgaussian1d - fit 1D Gaussian function fitgaussian2d - fit 2D Gaussian function fitgaussian2doriented - fit 2D Gaussian function that can be rotated fitgaussian3d - fit 3D Gaussian function fitl1line - perform linear regression but use an L1-error metric fitline2derror - fit a line to a set of 2D points using an error metric that is sensitive to both x and y fitnonlinearmodel - a useful wrapper around MATLAB's lsqcurvefit.m function fitnonlinearmodel_consolidate - consolidate .mat files written by fitnonlinearmodel fitnonlinearmodel_helper - a helper function for fitnonlinearmodel.m fitrbfpdf - fit a simplified mixture-of-Gaussians probability density function model using k-means fitrectpdf - fit a rectified squared model using k-means and interpret as a PDF fitrectdensity - fit a rectified squared model using k-means and interpret more like ANN gradientdescent - perform gradient descent or forward stagewise regression gradientdescent_wrapper - perform n-fold averaging technique for gradientdescent.m localregression - given a degree, kernel, and bandwidth, use local regression to predict values (surface defined on one dimension) localregression2d - given a degree, kernel, and bandwidth, use local regression to predict values (surface defined on two dimensions) localregression3d - given a degree, kernel, and bandwidth, use local regression to predict values (surface defined on three dimensions) localregression4d - given a degree, kernel, and bandwidth, use local regression to predict values (surface defined on four dimensions) localregressionbandwidth - cross-validate to determine the optimal bandwidth for local regression olscontrol - perform ordinary least-squares regression while controlling for some given regressors olsmatrix - perform ordinary least-squares regression olsmatrix2 - perform ordinary least-squares regression (fast mode) outputfcnplot - plot parameter history during an optimization outputfcnsanitycheck - explicit check on the size of the residuals to prevent infinite computation performfreqwhitening - flatten the average amplitude spectra of a set of images performpcawhitening - whiten a matrix in the PCA sense projectionmatrix - project out a linear subspace using ordinary least-squares regression randgg - generate random numbers from a generalized Gaussian randintrange,randintrange2 - randomly choose integers within a given range randnmulti - generate random numbers from a multivariate Gaussian randomization - calculate p-values using randomization randomorthogonalbasis - generate a random set of orthogonal basis functions resamplingtransform - a utility function to deal with cross-validation ordering as used in fitnonlinearmodel.m roundpvalue - round p-value up to have the form Xe-Y runkmeans - run the k-means clustering algorithm subspaceapprox - calculate correlation between a subspace and a vector timeseries/ calcpeak - calculate the peak of some time-series data (using interpolation) constructbutterfilter1D - construct a Fourier-domain Butterworth filter conv2run - convolve but keep runs separate deconvolvevectors - deconvolve one vector from another vector fouriertospace1D - convert magnitude filter in Fourier domain to the space domain generatepinknoise1D - generate samples of pink noise processmulti1D - apply a function that expects a single vector to multiple vectors sincshift - shift time-series data using sinc interpolation and padding tseriesinterp - interpolate time-series to achieve a new sampling rate tsfilter - filter time-series data with a Fourier-defined magnitude-based filter imageprocessing/ applymultiscalegaborfilters - filter images with a set of multi-scale Gabor filters applymultiscalegaussianfilters - filter images with a set of multi-scale Gaussian or Difference-of-Gaussians filters ba_interp3_wrapper - convenient wrapper for the 3D interpolation toolbox ba_interp3 calcamplitudespectrum - calculate a smooth function relating spatial frequency to amplitude calccpfov - return number of cycles per FOV associated with fft2 after fftshifting calccpfov1D - return number of cycles per FOV associated with fft after fftshifting calccpfov3D - return number of cycles per FOV associated with fftn (in three dimensions) after fftshifting calcimagecoordinates - return coordinates of the pixels of an image calcpositiondifferentfov - determine the coordinates of a new image with respect to an original image calcunitcoordinates - return coordinates of points equally spaced within the square bounded by -.5 and .5 checkimagesize - inspect pixel dimensions of a batch of image files chtoim - reshape image(s) from images x res*res to res x res x images concatimages - concatenate multiple images together constructbutterfilter - construct a Fourier-domain Butterworth filter (for images) constructbutterfilter3D - construct a Fourier-domain Butterworth filter (for volumes) constructcosinefilter - construct a Fourier-domain cosine-tapered filter constructorientationfilter - construct a Fourier-domain orientation filter (von Mises distribution) constructsmoothingfilter - construct a space-domain 2D or 3D Gaussian filter constructwhiteningfilter - construct a Fourier-domain whitening filter detectedges - detect edges in an image using simple scheme evaldog2d - evaluate 2D Difference-of-Gaussians function at some coordinates evalgabor2d - evaluate 2D Gabor function at some coordinates evalgrating2d - evaluate 2D sinusoidal grating function at some coordinates evalorientedgaussian2d - evaluate oriented 2D Gaussian at some coordinates evalrbf2d - evaluate 2D radial basis function at some coordinates extractwindow - easily pull out different chunks of an image fitgabor2d - fit 2D Gabor function fitorientedgaussian2d - fit oriented 2D Gaussian fitrbf2d - fit 2D radial basis function fftshift2 - apply fftshift along the first two dimensions flattenspectra - apply spatial frequency filtering to flatten the spectra of some images fouriertospace - convert magnitude filter in Fourier domain to the space domain gabortransform - perform Gabor transformation on one or more images generatepinknoise - generate samples of pink noise generaterandomphase - generate random phases suitable for multiplication with output of fft2 generatewinnermap - compress multidimensional data by using hue and brightness to represent the maximum value along a dimension getsamplebrain - return a brain volume getsampleimage - return a 500x500 grayscale natural image ifftshift2 - apply ifftshift along the first two dimensions imagefilter - filter images with a Fourier-defined magnitude-based filter imagefilter3D - filter volumes with a Fourier-defined magnitude-based filter imagesearch - search through image space to minimize some cost function imagesequenceconcatenate - concatenate multiple image files together imagesequencetomovie - make a QT movie from images imaveragefiles - average multiple image files together imcropfiles - manually define a crop region and then apply to one or more image files imreadmulti - load in multiple images imrectsquare - enforce square and integer crop to an imrect imrectimagecrop - return a valid image crop from imrect imresizedifferentfov - resize an image but use a different field-of-view imresizememory - call imresize on a bunch of images, minimizing memory usage imwritemulti - write multiple images to multiple files imtoch - reshape image(s) from res x res x images to images x res*res makecircleimage - draw a circle as an image makecolorimagestack - convert a 4D matrix containing multiple color images into a 3D matrix makeconcentricgrating2d - make a concentric 2D sinusoidal grating makedog2d - make a 2D Difference-of-Gaussians makegabor2d - make a 2D Gabor makegaussian2d - make a 2D Gaussian makegaussian3d - make a 3D Gaussian makegrating2d - make a 2D sinusoidal grating makegratings2d - make a set of 2D sinusoidal gratings makeimagestack - convert a 3D matrix containing multiple images into a 2D matrix makeimagestack_wrapper - run makeimagestack for multiple 3D matrices makeimagestack3dfiles - like makeimagestack but write out some convenient .png files makeorientedgaussian2d - make an oriented 2D Gaussian makesquareimage - draw a square as an image maskmultiscalegaborfilters - modify results of applymultiscalegaborfilters according to a binary mask phasescrambleimage - blend image with random-phase image placeimageintosquare - place an image anywhere within another image processimages - perform some function on many image files processmulti - apply a function that expects a single image to multiple images scrambleimage - scramble an image, preserving chunks of a certain size smoothvolumes - use a Gaussian filter to smooth one or more 3D volumes socmodel - compute the response of the SOC model to some stimuli splitimages - split images into chunks unitlengthfft2 - unit-length-normalize a Fourier domain filter varycontrast - vary the contrast of an image viewimage - do some visualizations for a given image viewimages - visualize many images at once viewmovie - view a series of images as a movie (or write a series of image files) visualizemultiscalegaborfilters- visualize points associated with applymultiscalegaborfilters figure/ addlogticks - add logarithmic ticks to a figure whose data have already been log-transformed axissquarify - make axis equal-aspect, square, and origin-centered and draw unity line errorbar2 - draw error bars (as lines) errorbar3 - draw error bars (as a polygon) figureprep - make an invisible figure window figurewrite - write the invisible figure window to an image file getcolorchar - take an integer and get a color character getfigurepos - return figure position (in normalized units) hist1dimage - draw a histogram as a vertical 1D image histrobust - run hist but ensuring a robust range imageactual - draw an image at its native resolution imagescmulti - make separate figure windows for multiple images plotorientedbar - plot an oriented bar plotrectangle - plot a rectangle printnice - print figure window to file setaxispos - set axis position (without mangling the Units setting) setfigurepos - set figure position (without mangling the Units setting) scatterb - do a binned scatterplot scatterline - use local linear regression to summarize a scatterplot scattersparse - do a scatterplot but limit the number of points scatterimagesparse - do a image scatterplot and limit the number of points squarify - figure out a roughly evenly balanced number of rows and columns necessary to fit a certain number of elements straightline - draw horizontal or vertical lines subplotresize - make the subplots of a figure as big as possible colormap/ cmapang - hue-based colormap suitable for circular ranges (e.g. angles) cmapangLR - like cmapang.m but left-right flipped cmapangLVF - like cmapang.m but focused on the left visual field cmapangRVF - like cmapang.m but focused on the right visual field cmapdistinct - hue-based colormap for cases where you want maximally distinct colors cmaplookup - take values and get colors from colormap cmaphue - hue-based colormap suitable for circular ranges cmapsinglecolor - generate colormap that mixes from one color to a second color cmapsign - blue-black-red colormap suitable for ranges like [-X X] cmapsign2 - blue-white-red colormap suitable for ranges like [-X X] cmapsign3 - blue-lightgray-red colormap suitable for ranges like [-X X] cmapsign4 - cyan-blue-black-red-yellow colormap suitable for ranges like [-X X] cmaptab10 - a set of 10 discrete colors cmapturbo - jet-like colormap colorinterpolate - make a colormap by interpolating between key colors drawcolorbar - draw a colorbar on the current figure drawcolorbarcircular - draw a circular colorbar on the current figure graphic/ calcdistpointline - calculate the distance between one or more points and a line circlewithin - determine whether one or more circles are contained within a certain circle coordangle - calculate coordinates of an angle coordpolygon - calculate coordinates of an equilateral polygon createrescalingmatrix - construct a transformation matrix that rescales with respect to (0.5,0.5,0.5) defineellipse3d - allow user to define a 3D ellipse on a 3D volume drawarrow - draw an arrow (in two dimensions) drawbar - draw an oriented bar drawbars - draw a set of oriented bars drawbartexture - draw a random array of oriented bars drawcheckerboard - draw an oriented checkerboard drawcheckerboards - draw a set of oriented checkerboards drawclosedcontour - draw a generic closed contour shape drawclosedcontours - render several closed contours drawdartboard - draw a radial checkerboard (dartboard) drawellipse - draw a complete or partial ellipse (includes circles and arcs as special cases) drawmultiscale - place objects at multiple scales on a pink-noise background drawpolargrid - draw a polar grid consisting of rings and spokes drawrectangle - draw a rectangle drawsector - draw a sector drawtext - draw a word drawtexts - render several words renderfigure - render the current figure into an image (assumed to be square) xyzscale - construct a scaling transformation matrix xyztranslate - construct a translating transformation matrix xyzrotate_* - construct a rotation transformation matrix xyzrotatetoz - return rotation transformation matrix to align a vector with positive z-axis mri/ calchrfpeak - estimate the peak (positive or negative) value of an HRF changevolumeres - change the resolution of a volume while preserving field-of-view computebrickandindices - determine a brick into a 3D binary volume computetemporalsnr - compute the stability of a series of 3D volumes over time condition_split - perform condition-splitting on a set of design matrices constructhrfmodeldct - return a matrix of DCT-II basis functions for modeling HRFs constructhrfmodeldelta - return a matrix of delta basis functions for modeling HRFs constructhrfmodelspline - return an spline-based HRF model constructstimulusmatrices - construct design matrix for a finite impulse response (FIR) model copyxform_nii - propagate transformation-related fields from one NII file to others coregistervolumes - coregister one volume to another createspmmatrix - return the default SPM transformation matrix dicomloaddir - load volumes and voxel-size information from a DICOM directory evaldoublegamma - evaluate double-gamma function at some x-values expdesignefficiency - calculate efficiency of an experimental design fithrfgammadouble.m - fit a double-gamma function fmriquality - write figures to inspect the spatial quality of fMRI volumes fstoint - go from FreeSurfer space to our internal space getcanonicalhrf - return a canonical HRF (based on empirical data) for arbitrary duration and TR getcanonicalhrf2 - return canonical Early and Late HRFs (based on empirical data) for arbitrary duration and TR getcanonicalhrflibrary - return a set of canonical HRFs (based on empirical data) for arbitrary duration and TR getsamplehrf - return some sample HRFs estimated from actual fMRI data homogenizevolumes - homogenize a set of 3D volumes by dividing by fitted 3D polynomials hrfgammadouble.m - evaluate a double-gamma function inttofs - go from our internal space to FreeSurfer space motioncorrectvolumes - perform motion correction for some volumes preconditionvolume - precondition a 3D volume by clipping outliers and removing low-frequency signal variations quantifymotionparameters - compute an intuitive summary metric of rigid-body motion during a run resliceniftitomatch - use NIFTI header information to match one volume to another settr_nii - set the TR in the header information of an NII structure surfaceslice2 - figure out information relating voxels to vertices undistortvolumes - resample volumes in order to correct for motion and distortion write3dstack - write out extracted slices in three orientations from a 3D matrix writespmfiles - write a series of volumes to individual SPM/ANALYZE files pt/ calcfixationdotchangeperformance - perform analysis of behavioral data for experiments involving dot change detection preparedigits - generate some digits and letters as uint8 images pteyelinkoff - some eye-tracking related setup pteyelinkon - some eye-tracking related setup pton - initialize PsychToolbox stuff ptoff - uninitialize PsychToolbox stuff ptviewimage - show one or more images and allow user to position the images ptviewmovie - show a stimulus movie ptviewmoviecheck - check the results of ptviewmovie.m runretinotopy - script for retinotopy experiment showmulticlass - helper function for various experiments external/ [code obtained from elsewhere] hist2d.m - count histogram frequencies in two dimensions %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% COPYRIGHT Copyright (c) 2013, Kendrick Kay All rights reserved. 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