文章目录：
- 1、求MATLAB中filter2函数的源代码。
- 2、javax.servlet.Filter 中操作 javax.servlet.http.HttpServletRequest
- 3、股票源码公式中的FILTER函数是未来函数吗？会有漂移吗？为什么加入后准确率大大提高？
- 4、jQuery源码分析之实例find和filter方法的区别七问
求MATLAB中filter2函数的源代码。
若需要函数体，我可以传文件给你。下面是其代码function y = filter2(b,x,shape)
%FILTER2 Two-dimensional digital filter.
% Y = FILTER2(B,X) filters the data in X with the 2-D FIR
% filter in the matrix B. The result, Y, is computed
% using 2-D correlation and is the same size as X.
%
% Y = FILTER2(B,X,'shape') returns Y computed via 2-D
% correlation with size specified by 'shape':
% 'same' - (default) returns the central part of the
% correlation that is the same size as X.
% 'valid' - returns only those parts of the correlation
% that are computed without the zero-padded
% edges, size(Y) size(X).
% 'full' - returns the full 2-D correlation,
% size(Y) size(X).
%
% FILTER2 uses CONV2 to do most of the work. 2-D correlation
% is related to 2-D convolution by a 180 degree rotation of the
% filter matrix.
%
% Class support for inputs B,X:
% float: double, single
%
% See also FILTER, CONV2.% Copyright 1984-2004 The MathWorks, Inc.
% $Revision: 5.13.4.2 $ $Date: 2004/03/09 16:16:19 $error(nargchk(2,3,nargin));
if nargin3, shape = 'same'; endif (~isa(b,'float')), b = double(b); end
if (~isa(x,'float')), x = double(x); endcode = [shape,' ']; code = code(1);
if isempty(find(code=='svf'))
error('MATLAB:filter2:InvalidParam', 'Unknown shape parameter.');
end[mx,nx] = size(x);
stencil = rot90(b,2);
[ms,ns] = size(stencil);% 1-D stencil?
if (ms == 1)
y = conv2(1,stencil,x,shape);
elseif (ns == 1)
y = conv2(stencil,1,x,shape);
else
if (ms*ns mx*nx)
% The filter is bigger than the input. This is a nontypical
% case, and it may be counterproductive to check the
% separability of the stencil.
y = conv2(x,stencil,shape);
else
separable = false;
if all(isfinite(stencil(:)))
% Check rank (separability) of stencil
[u,s,v] = svd(stencil);
s = diag(s);
tol = length(stencil) * eps(max(s));
rank = sum(s tol);
separable = (rank ==1);
end
if separable
% Separable stencil
hcol = u(:,1) * sqrt(s(1));
hrow = conj(v(:,1)) * sqrt(s(1));
if (all(all((round(stencil) == stencil))) all(all((round(x) == x))))
% Output should be integer
y = round(conv2(hcol, hrow, x, shape));
else
y = conv2(hcol, hrow, x, shape);
end
else
% Nonseparable stencil
y = conv2(x,stencil,shape);
end
end
end
javax.servlet.Filter 中操作 javax.servlet.http.HttpServletRequest
doFilter(javax.servlet.ServletRequest arg0, javax.servlet.ServletResponse arg1, javax.servlet.FilterChain arg2) throws java.io.IOException, javax.servlet.ServletException;
这是Filter的源码。本身就有javax.servlet.ServletRequest 你将这个强转一下就获取到HttpServletRequest了。获取请求。request.getRequestURL() ，然后你判断一个这个是否是endwith("html"); 直接让FilterChain 跳转到jsp上就行了啊。
股票源码公式中的FILTER函数是未来函数吗？会有漂移吗？为什么加入后准确率大大提高？
filter不是未来函数，是在上一个信号出现后，在多长时间不再提示
比如kdj的金叉，如果今天金叉，用filter过滤5天，那5天内再出现金叉就不提示了。所以filter很安全
jQuery源码分析之实例find和filter方法的区别七问
filter()过滤DOM元素包装集，是指操作当前元素集，删除不匹配的元素，得到一个新的集合
$('div').filter('.div1');//选择div标签中class属性为div1的div元素
find()在当前选中元素的上下文中找到符合条件的后代，返回的是子元素
$('div').find('em');//选择div标签中的em标签的元素
filter()是对选中的元素集合操作，得到这些元素中符合条件的元素，而find()是得到选中元素 中符合条件的后代子元素。
without the zero-padded% edges, size(Y) size(X).% 'full' - returns the full 2-D correlation, %