convones
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| — | convones [2010/06/22 03:10] (current) – created jochen | ||
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| + | ====== convones ====== | ||
| + | ===== Motivation ===== | ||
| + | The main motivation to use convones is to have a faster routine for the special case where one of the arguments of a one-dimensional convolution is a series of all-1 values. | ||
| + | |||
| + | ===== Reference ===== | ||
| + | < | ||
| + | |||
| + | FORMAT: | ||
| + | |||
| + | Input fields: | ||
| + | |||
| + | f | ||
| + | cnum number of consecutive ones to use | ||
| + | w if 1x1 true, weight (divide by number of samples) | ||
| + | |||
| + | Output fields: | ||
| + | |||
| + | cfunc | ||
| + | |||
| + | See also conv</ | ||
| + | |||
| + | ===== Used by ===== | ||
| + | The main internal use for this function is the creation of design matrices. Opposed to SPM (which typically uses a 16 timebin-per-TR resolution), | ||
| + | |||
| + | ===== Exemplary use ===== | ||
| + | <code matlab conv_ones_rectwindow.m> | ||
| + | k = smoothkern(2000); | ||
| + | |||
| + | % convolve with a all-ones vector of equal length | ||
| + | tic, ko = convones(k, numel(k)); toc | ||
| + | % reference: Elapsed time is 0.024565 seconds. | ||
| + | |||
| + | % and now the same with conv | ||
| + | tic, koc = conv(k, ones(numel(k), | ||
| + | % reference: Elapsed time is 0.240042 seconds.</ | ||
| + | |||
| + | Note: the difference gets larger the longer the vectors become!! | ||
convones.txt · Last modified: 2010/06/22 03:10 by jochen
