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[Octave-cvsupdate] SF.net SVN: octave:[10386] trunk/octave-forge/main/signal/inst
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From: <mtm...@us...> - 2012-05-09 03:49:16
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Revision: 10386
http://octave.svn.sourceforge.net/octave/?rev=10386&view=rev
Author: mtmiller
Date: 2012-05-09 03:49:09 +0000 (Wed, 09 May 2012)
Log Message:
-----------
signal: make window length argument consistent across all functions
Modified Paths:
--------------
trunk/octave-forge/main/signal/inst/chebwin.m
trunk/octave-forge/main/signal/inst/flattopwin.m
trunk/octave-forge/main/signal/inst/gausswin.m
trunk/octave-forge/main/signal/inst/kaiser.m
trunk/octave-forge/main/signal/inst/rectwin.m
trunk/octave-forge/main/signal/inst/triang.m
trunk/octave-forge/main/signal/inst/tukeywin.m
Modified: trunk/octave-forge/main/signal/inst/chebwin.m
===================================================================
--- trunk/octave-forge/main/signal/inst/chebwin.m 2012-05-09 01:25:06 UTC (rev 10385)
+++ trunk/octave-forge/main/signal/inst/chebwin.m 2012-05-09 03:49:09 UTC (rev 10386)
@@ -13,9 +13,9 @@
## You should have received a copy of the GNU General Public License along with
## this program; if not, see <http://www.gnu.org/licenses/>.
-## Usage: chebwin (n, at)
+## Usage: chebwin (L, at)
##
-## Returns the filter coefficients of the n-point Dolph-Chebyshev window
+## Returns the filter coefficients of the L-point Dolph-Chebyshev window
## with at dB of attenuation in the stop-band of the corresponding
## Fourier transform.
##
@@ -31,13 +31,13 @@
##
## The window is described in frequency domain by the expression:
##
-## Cheb(n-1, beta * cos(pi * k/n))
+## Cheb(L-1, beta * cos(pi * k/L))
## W(k) = -------------------------------
-## Cheb(n-1, beta)
+## Cheb(L-1, beta)
##
## with
##
-## beta = cosh(1/(n-1) * acosh(10^(at/20))
+## beta = cosh(1/(L-1) * acosh(10^(at/20))
##
## and Cheb(m,x) denoting the m-th order Chebyshev polynomial calculated
## at the point x.
@@ -48,38 +48,38 @@
##
## See also: kaiser
-function w = chebwin (n, at)
+function w = chebwin (L, at)
if (nargin != 2)
print_usage;
- elseif !(isscalar (n) && (n == round(n)) && (n > 0))
- error ("chebwin: n has to be a positive integer");
+ elseif !(isscalar (L) && (L == round(L)) && (L > 0))
+ error ("chebwin: L has to be a positive integer");
elseif !(isscalar (at) && (at == real (at)))
error ("chebwin: at has to be a real scalar");
endif
- if (n == 1)
+ if (L == 1)
w = 1;
else
# beta calculation
gamma = 10^(-at/20);
- beta = cosh(1/(n-1) * acosh(1/gamma));
+ beta = cosh(1/(L-1) * acosh(1/gamma));
# freq. scale
- k = (0:n-1);
- x = beta*cos(pi*k/n);
+ k = (0:L-1);
+ x = beta*cos(pi*k/L);
# Chebyshev window (freq. domain)
- p = cheb(n-1, x);
+ p = cheb(L-1, x);
# inverse Fourier transform
- if (rem(n,2))
+ if (rem(L,2))
w = real(fft(p));
- M = (n+1)/2;
+ M = (L+1)/2;
w = w(1:M)/w(1);
w = [w(M:-1:2) w]';
else
# half-sample delay (even order)
- p = p.*exp(j*pi/n * (0:n-1));
+ p = p.*exp(j*pi/L * (0:L-1));
w = real(fft(p));
- M = n/2+1;
+ M = L/2+1;
w = w/w(2);
w = [w(M:-1:2) w(2:M)]';
endif
Modified: trunk/octave-forge/main/signal/inst/flattopwin.m
===================================================================
--- trunk/octave-forge/main/signal/inst/flattopwin.m 2012-05-09 01:25:06 UTC (rev 10385)
+++ trunk/octave-forge/main/signal/inst/flattopwin.m 2012-05-09 03:49:09 UTC (rev 10386)
@@ -1,15 +1,15 @@
## Author: Paul Kienzle <pki...@us...> (2004)
## This program is granted to the public domain.
-## flattopwin(n, [periodic|symmetric])
+## flattopwin(L, [periodic|symmetric])
##
## Return the window f(w):
##
## f(w) = 1 - 1.93 cos(2 pi w) + 1.29 cos(4 pi w)
## - 0.388 cos(6 pi w) + 0.0322cos(8 pi w)
##
-## where w = i/(n-1) for i=0:n-1 for a symmetric window, or
-## w = i/n for i=0:n-1 for a periodic window. The default
+## where w = i/(L-1) for i=0:L-1 for a symmetric window, or
+## w = i/L for i=0:L-1 for a periodic window. The default
## is symmetric. The returned window is normalized to a peak
## of 1 at w = 0.5.
##
@@ -23,23 +23,23 @@
## [1] Gade, S; Herlufsen, H; (1987) "Use of weighting functions in DFT/FFT
## analysis (Part I)", Bruel & Kjaer Technical Review No.3.
-function w = flattopwin (n, sym)
+function w = flattopwin (L, sym)
if nargin == 0 || nargin > 2
print_usage;
endif
- divisor = n-1;
+ divisor = L-1;
if nargin > 1
match = strmatch(sym,['periodic';'symmetric']);
if isempty(match),
error("window type must be periodic or symmetric");
elseif match == 1
- divisor = n;
+ divisor = L;
else
- divisor = n-1;
+ divisor = L-1;
endif
endif
- x = 2*pi*[0:n-1]'/divisor;
+ x = 2*pi*[0:L-1]'/divisor;
w = (1-1.93*cos(x)+1.29*cos(2*x)-0.388*cos(3*x)+0.0322*cos(4*x))/4.6402;
endfunction
Modified: trunk/octave-forge/main/signal/inst/gausswin.m
===================================================================
--- trunk/octave-forge/main/signal/inst/gausswin.m 2012-05-09 01:25:06 UTC (rev 10385)
+++ trunk/octave-forge/main/signal/inst/gausswin.m 2012-05-09 03:49:09 UTC (rev 10386)
@@ -13,21 +13,21 @@
## You should have received a copy of the GNU General Public License along with
## this program; if not, see <http://www.gnu.org/licenses/>.
-## usage: w = gausswin(n, a)
+## usage: w = gausswin(L, a)
##
-## Generate an n-point gaussian window of the given width. Use larger a
-## for a narrow window. Use larger n for a smoother curve.
+## Generate an L-point gaussian window of the given width. Use larger a
+## for a narrow window. Use larger L for a smoother curve.
##
## w = exp ( -(a*x)^2/2 )
##
-## for x = linspace(-(n-1)/n, (n-1)/n, n)
+## for x = linspace(-(L-1)/L, (L-1)/L, L)
-function x = gausswin(n, w)
+function x = gausswin(L, w)
if nargin < 1 || nargin > 2
print_usage;
end
if nargin == 1, w = 2.5; endif
- x = exp ( -0.5 * ( w/n * [ -(n-1) : 2 : n-1 ]' ) .^ 2 );
+ x = exp ( -0.5 * ( w/L * [ -(L-1) : 2 : L-1 ]' ) .^ 2 );
endfunction
Modified: trunk/octave-forge/main/signal/inst/kaiser.m
===================================================================
--- trunk/octave-forge/main/signal/inst/kaiser.m 2012-05-09 01:25:06 UTC (rev 10385)
+++ trunk/octave-forge/main/signal/inst/kaiser.m 2012-05-09 03:49:09 UTC (rev 10386)
@@ -14,36 +14,36 @@
## You should have received a copy of the GNU General Public License along with
## this program; if not, see <http://www.gnu.org/licenses/>.
-## usage: kaiser (n, beta)
+## usage: kaiser (L, beta)
##
-## Returns the filter coefficients of the n-point Kaiser window with
+## Returns the filter coefficients of the L-point Kaiser window with
## parameter beta.
##
## For the definition of the Kaiser window, see A. V. Oppenheim &
## R. W. Schafer, "Discrete-Time Signal Processing".
##
-## The continuous version of width n centered about x=0 is:
+## The continuous version of width L centered about x=0 is:
##
-## besseli(0, beta * sqrt(1-(2*x/n).^2))
-## k(x) = -------------------------------------, n/2 <= x <= n/2
+## besseli(0, beta * sqrt(1-(2*x/L).^2))
+## k(x) = -------------------------------------, L/2 <= x <= L/2
## besseli(0, beta)
##
## See also: kaiserord
-function w = kaiser (n, beta = 0.5)
+function w = kaiser (L, beta = 0.5)
if (nargin < 1)
print_usage;
- elseif !(isscalar (n) && (n == round (n)) && (n > 0))
- error ("kaiser: n has to be a positive integer");
+ elseif !(isscalar (L) && (L == round (L)) && (L > 0))
+ error ("kaiser: L has to be a positive integer");
elseif !(isscalar (beta) && (beta == real (beta)))
error ("kaiser: beta has to be a real scalar");
endif
- if (n == 1)
+ if (L == 1)
w = 1;
else
- m = n - 1;
+ m = L - 1;
k = (0 : m)';
k = 2 * beta / m * sqrt (k .* (m - k));
w = besseli (0, k) / besseli (0, beta);
Modified: trunk/octave-forge/main/signal/inst/rectwin.m
===================================================================
--- trunk/octave-forge/main/signal/inst/rectwin.m 2012-05-09 01:25:06 UTC (rev 10385)
+++ trunk/octave-forge/main/signal/inst/rectwin.m 2012-05-09 03:49:09 UTC (rev 10386)
@@ -14,12 +14,12 @@
## this program; if not, see <http://www.gnu.org/licenses/>.
## -*- texinfo -*-
-## @deftypefn {Function File} {[@var{w}] =} rectwin(@var{n})
-## Return the filter coefficients of a rectangle window of length N.
+## @deftypefn {Function File} {[@var{w}] =} rectwin(@var{L})
+## Return the filter coefficients of a rectangle window of length L.
## @seealso{hamming, hanning}
## @end deftypefn
-function w = rectwin(n)
+function w = rectwin(L)
if (nargin < 1); print_usage; end
- w = ones(round(n),1);
+ w = ones(round(L),1);
endfunction
Modified: trunk/octave-forge/main/signal/inst/triang.m
===================================================================
--- trunk/octave-forge/main/signal/inst/triang.m 2012-05-09 01:25:06 UTC (rev 10385)
+++ trunk/octave-forge/main/signal/inst/triang.m 2012-05-09 03:49:09 UTC (rev 10386)
@@ -13,20 +13,20 @@
## You should have received a copy of the GNU General Public License along with
## this program; if not, see <http://www.gnu.org/licenses/>.
-## usage: w = triang (n)
+## usage: w = triang (L)
##
-## Returns the filter coefficients of a triangular window of length n.
+## Returns the filter coefficients of a triangular window of length L.
## Unlike the bartlett window, triang does not go to zero at the edges
-## of the window. For odd n, triang(n) is equal to bartlett(n+2) except
+## of the window. For odd L, triang(L) is equal to bartlett(L+2) except
## for the zeros at the edges of the window.
-function w = triang(n)
+function w = triang(L)
if (nargin != 1)
print_usage;
- elseif (!isscalar(n) || n != fix (n) || n < 1)
- error("triang(n): n has to be an integer > 0");
+ elseif (!isscalar(L) || L != fix (L) || L < 1)
+ error("triang: L has to be an integer > 0");
endif
- w = 1 - abs ([-(n-1):2:(n-1)]' / (n+rem(n,2)));
+ w = 1 - abs ([-(L-1):2:(L-1)]' / (L+rem(L,2)));
endfunction
%!error triang
Modified: trunk/octave-forge/main/signal/inst/tukeywin.m
===================================================================
--- trunk/octave-forge/main/signal/inst/tukeywin.m 2012-05-09 01:25:06 UTC (rev 10385)
+++ trunk/octave-forge/main/signal/inst/tukeywin.m 2012-05-09 03:49:09 UTC (rev 10386)
@@ -14,9 +14,9 @@
## this program; if not, see <http://www.gnu.org/licenses/>.
## -*- texinfo -*-
-## @deftypefn {Function File} {@var{w} =} tukeywin (@var{m}, @var{r})
+## @deftypefn {Function File} {@var{w} =} tukeywin (@var{L}, @var{r})
## Return the filter coefficients of a Tukey window (also known as the
-## cosine-tapered window) of length @var{m}. @var{r} defines the ratio
+## cosine-tapered window) of length @var{L}. @var{r} defines the ratio
## between the constant section and and the cosine section. It has to be
## between 0 and 1. The function returns a Hanning window for @var{r}
## egals 0 and a full box for @var{r} egals 1. By default @var{r} is set
@@ -28,7 +28,7 @@
## Page 67, Equation 38.
## @end deftypefn
-function w = tukeywin (m, r = 1/2)
+function w = tukeywin (L, r = 1/2)
if (nargin < 1 || nargin > 2)
print_usage;
@@ -45,23 +45,23 @@
switch r
case 0,
## full box
- w = ones (m, 1);
+ w = ones (L, 1);
case 1,
## Hanning window
- w = hanning (m);
+ w = hanning (L);
otherwise
## cosine-tapered window
- t = linspace(0,1,m)(1:end/2)';
+ t = linspace(0,1,L)(1:end/2)';
w = (1 + cos(pi*(2*t/r-1)))/2;
- w(floor(r*(m-1)/2)+2:end) = 1;
- w = [w; ones(mod(m,2)); flipud(w)];
+ w(floor(r*(L-1)/2)+2:end) = 1;
+ w = [w; ones(mod(L,2)); flipud(w)];
endswitch
endfunction
%!demo
-%! m = 100;
+%! L = 100;
%! r = 1/3;
-%! w = tukeywin (m, r);
-%! title(sprintf("%d-point Tukey window, R = %d/%d", m, [p, q] = rat(r), q));
+%! w = tukeywin (L, r);
+%! title(sprintf("%d-point Tukey window, R = %d/%d", L, [p, q] = rat(r), q));
%! plot(w);
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