我应该每次取两个句子并计算它们是否相似。我的意思是在句法和语义上都类似。
输入1:奥巴马签署法律。奥巴马签署了一项新法律。
INPUT2: 一辆巴士停在这里。一辆车停在这里。
输入 3:纽约火灾。纽约被烧毁了。
输入 4:纽约发生火灾。50人死于纽约大火。
我不想使用本体树作为灵魂。我编写了一个代码来计算句子之间的Levenshtein 距离(LD),然后确定第二个句子是否:
- 可以忽略(INPUT1 和 2),
- 应该替换第一句(INPUT 3),或者
- 与第一句(INPUT4)一起存储。
我对代码不满意,因为 LD 只计算语法级别(还有什么其他方法?)。如何结合语义(就像公共汽车是一种车辆?)。
代码在这里:
%# As the difference is computed, a decision is made on the new event
%# (string 2) to be ignored, to replace existing event (string 1) or to be
%# stored separately. The higher the LD metric, the higher the difference
%# between two strings. Of course, lower difference indices either identical
%# or similar events. However, the higher difference indicates the new event
%# as a fresh event.
%#.........................................................................
%# Calculating the LD between two strings of events.
%#.........................................................................
L1=length(str1)+1;
L2=length(str2)+1;
L=zeros(L1,L2); %# Initializing the new length.
g=+1; %# just constant
m=+0; %# match is cheaper, we seek to minimize
d=+1; %# not-a-match is more costly.
% do BC's
L(:,1)=([0:L1-1]*g)';
L(1,:)=[0:L2-1]*g;
m4=0; %# loop invariant
%# Calculating required edits.
for idx=2:L1;
for idy=2:L2
if(str1(idx-1)==str2(idy-1))
score=m;
else
score=d;
end
m1=L(idx-1,idy-1) + score;
m2=L(idx-1,idy) + g;
m3=L(idx,idy-1) + g;
L(idx,idy)=min(m1,min(m2,m3)); % only minimum edits allowed.
end
end
%# The LD between two strings.
D=L(L1,L2);
%#....................................................................
%# Making decision on what to do with the new event (string 2).
%#...................................................................
if (D<=4) %# Distance is so less that string 2 seems identical to string 1.
store=str1; %# Hence string 2 is ignored. String 1 remains stored.
elseif (D>=5 && D<=15) %# Distance is larger to be identical but not enough to
%# make string 2 an individual event.
store= str2; %# String 2 is somewhat similar to string 1.
%# So, string 1 is replaced with string 2 and stored.
else
%# For all other distances, string 2 is stored along with string 1.
store={str1; str2};
end
任何帮助表示赞赏。