Mercurial > octave
changeset 26249:78c4aadfbfd9
movfun.m, movslice.m: Add support for even-size, asymmetric windows for Matlab compatibility.
* movfun.m: Rewrite documentation about scalar window length WLEN and provide
many example usages. Remove input validation check for symmetric window.
Remove BIST test checking for error when given an asymmetric WLEN.
* movslice.m: Remove input validation check for symmetric window.
Detect whether scalar WLEN is even or odd. Add new calculation
for indices of asymmetric window. Remove BIST test checking for error when
given an asymmetric WLEN.
| author | Rik <rik@octave.org> |
|---|---|
| date | Sun, 16 Dec 2018 22:24:10 -0800 |
| parents | 8a0778f549e8 |
| children | 481708dbc540 |
| files | scripts/signal/movfun.m scripts/signal/movslice.m |
| diffstat | 2 files changed, 32 insertions(+), 22 deletions(-) [+] |
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--- a/scripts/signal/movfun.m Sun Dec 16 15:21:48 2018 -0800 +++ b/scripts/signal/movfun.m Sun Dec 16 22:24:10 2018 -0800 @@ -27,12 +27,23 @@ ## @var{x}. ## ## If @var{wlen} is a scalar, the function @var{fcn} is applied to a moving -## window of length @var{wlen}. In this case @var{wlen} must be an odd number. +## window of length @var{wlen}. When @var{wlen} is an odd number the window is +## symmetric and includes @code{(@var{wlen} - 1) / 2} elements on either side +## of the central element. For example, when calculating the output at +## index 5 with a window length of 3, @code{movfun} uses data elements +## @code{[4, 5, 6]. If @var{wlen} is an even number, the window is asymmetric +## and has @code{@var{wlen}/2} elements to the left of the central element +## and @code{@var{wlen}/2 - 1} elements to the right of the central element. +## For example, when calculating the output at index 5 with a window length of +## 4, @code{movfun} uses data elements @code{[3, 4, 5, 6]}. +## ## If @var{wlen} is an array with two elements @w{@code{[@var{nb}, @var{na}]}}, ## the function is applied to a moving window @code{-@var{nb}:@var{na}}. This ## window includes @var{nb} number of elements @strong{before} the current ## element and @var{na} number of elements @strong{after} the current element. -## The current element is always included. +## The current element is always included. For example, given +## @code{@var{wlen} = [3, 0]}, the data used to calculate index 5 is +## @code{[2, 3, 4, 5]}. ## ## During calculations the data input @var{x} is reshaped into a 2-dimensional ## @var{wlen}-by-@var{N} matrix and @var{fcn} is called on this new matrix. @@ -184,10 +195,7 @@ endif if (isscalar (wlen)) ## Check for proper window length - ## FIXME: Matlab accepts even windows - if (mod (wlen, 2) == 0) - error ("Octave:invalid-input-arg", "movfun: WLEN must be an odd length"); - elseif (wlen == 1) + if (wlen == 1) error ("Octave:invalid-input-arg", "movfun: WLEN must be > 1"); endif elseif (numel (wlen) == 2) @@ -221,7 +229,7 @@ ## Obtain slicer [slc, C, Cpre, Cpos, win] = movslice (N, wlen); - ## FIXME: validation doesn't seem to work correctly + ## FIXME: Validation doesn't seem to work correctly (noted 12/16/2018). ## Validate that outdim makes sense tmp = fcn (zeros (length (win), 1)); # output for window noutdim = length (tmp); # number of output dimensions @@ -257,19 +265,19 @@ endfunction -function y = movfun_oncol (fcn, x, wlen, bcfunc, I, C, Cpre, Cpos, win, odim) +function y = movfun_oncol (fcn, x, wlen, bcfunc, slcidx, C, Cpre, Cpos, win, odim) N = length (x); y = NA (N, odim); ## Process center part - y(C,:) = fcn (x(I)); + y(C,:) = fcn (x(slcidx)); ## Process boundaries - if (! isempty (Cpre)) # don't process zero length bkw-window + if (! isempty (Cpre)) y(Cpre,:) = bcfunc (fcn, x, Cpre, win, wlen, odim); endif - if (! isempty (Cpos)) # don't process zero length fwd-window + if (! isempty (Cpos)) y(Cpos,:) = bcfunc (fcn, x, Cpos, win, wlen, odim); endif @@ -573,7 +581,6 @@ %!error <WLEN must be .* array of integers> movfun (@min, 1, {1}) %!error <WLEN must be .* array of integers .= 0> movfun (@min, 1, -1) %!error <WLEN must be .* array of integers> movfun (@min, 1, 1.5) -%!error <WLEN must be an odd length> movfun (@min, 1, 4) %!error <WLEN must be . 1> movfun (@min, 1, 1) %!error <WLEN must be a scalar or 2-element array> movfun (@min, 1, [1, 2, 3]) %!error <WLEN \(3\) must be shorter than length along DIM1 \(1\)>
--- a/scripts/signal/movslice.m Sun Dec 16 15:21:48 2018 -0800 +++ b/scripts/signal/movslice.m Sun Dec 16 22:24:10 2018 -0800 @@ -49,10 +49,7 @@ endif if (isscalar (wlen)) ## Check for proper window length - ## FIXME: Matlab accepts even windows - if (mod (wlen, 2) == 0) - error ("Octave:invalid-input-arg", "movslice: WLEN must be an odd length"); - elseif (wlen == 1) + if (wlen == 1) error ("Octave:invalid-input-arg", "movslice: WLEN must be > 1"); endif elseif (numel (wlen) == 2) @@ -62,15 +59,22 @@ "movfun: WLEN must be a scalar or 2-element array of integers >= 0"); endif - ## FIXME: Eventually add support for asymmetric window if (isscalar (wlen)) - hwlen = (wlen - 1) / 2; - wlen = [hwlen, hwlen]; + if (mod (wlen, 2) == 1) + ## Symmetric window + nb = na = (wlen - 1) / 2; + wlen = [nb, na]; + else + ## Asymmetric window + nb = wlen / 2; + na = nb - 1; + wlen = [nb, na]; + endif endif Cpre = 1:wlen(1); # centers that can't fit the pre-window Cnf = N - wlen(2) + 1; # first center that can't fit the post-window - Cpost = Cnf:N; # centers that can't fit post-window + Cpost = Cnf:N; # centers that can't fit centered post-window C = (wlen(1) + 1):(Cnf - 1); win = (-wlen(1):wlen(2)).'; slcidx = C + win; @@ -78,7 +82,7 @@ endfunction -## FIXME: Need BIST functional tests +## FIXME: Need functional BIST tests ## Test input validation %!error movslice () @@ -87,6 +91,5 @@ %!error <WLEN must be .* array of integers> movslice (1, {1}) %!error <WLEN must be .* array of integers .= 0> movslice (1, -1) %!error <WLEN must be .* array of integers> movslice (1, 1.5) -%!error <WLEN must be an odd length> movslice (1, 4) %!error <WLEN must be . 1> movslice (1, 1) %!error <WLEN must be a scalar or 2-element array> movslice (1, [1, 2, 3])