Matlab script used in the paper "ISME - Incoherent Sampling of Multi-Echo data to minimize cardiac-induced noise in brain maps of R2* and magnetic susceptibility" to estimate the image-specific weights used in the nonlinear weighted least square fit of R2*. The code to run is "ISME_main". It is important to note that: To run the code, it is necessary to download SPM12 (https://www.fil.ion.ucl.ac.uk/spm/software/spm12/) The computation of the image-specific weights does not necessitate any toolboxes. In the current code version, Matlab's optimization toolbox is necessary to perform the R2* fit. The R2* fitting is faster if Matlab's parallel imaging toolbox is installed, but it is optional. The code comes with one of the datasets used in the paper. The face was masked out to preserve anonymity. This dataset contains magnitude/phase data for three repetitions of ISME and standard sampling multi-echo data. The output of the code is also provided: the image-specific weights, R2* maps, estimation of magnitude data at TE=0 and mean square error of the R2* fit.