Jaro-Winkler Matching Algorithm C -> Java
Does anyone want to try and convert this in to Java. I've done it but the return values I get back are different from those in Winkler's science paper and I just can't understand it. I looked over the code 5 times now changing bits a pieces to try an get it to work right
http://www.amstat.org/sections/srms/proceedings/papers/1990_056.pdf
go on give it a try. It's a pretty hand string compartor algorithm and ya might use it yourself one day
/* strcmp95.c*/
/* The strcmp95 function returns a double precision value from 0.0 (total
disagreement) to 1.0 (character-by-character agreement). The returned
value is a measure of the similarity of the two strings.*/
/* Date of Release: Jan. 26, 1994
Authors: This function was written using the logic from code written by
Bill Winkler, George McLaughlin and Matt Jaro with modifications
by Maureen Lynch.
Comment: This is the official string comparator to be used for matching
during the 1995 Test Census. */
#include <ctype.h>
#include <string.h>
#define NOTNUM(c)((c>57) || (c<48))
#define INRANGE(c)((c>0) && (c<91))
#define MAX_VAR_SIZE 61
#define NULL60""
double strcmp95(char *ying,char *yang,long y_length,int *ind_c[])
{
/* Arguments:
ying and yang are pointers to the 2 strings to be compared. The strings
need not be NUL-terminated strings because the length is passed.
y_length is the length of the strings.
ind_c is an array that is used to define whether certain options should be
activated. A nonzero value indicates the option is deactivated.
The options are:
ind_c[0] Increase the probability of a match when the number of matched
characters is large. This option allows for a little more
tolerance when the strings are large. It is not an appropriate
test when comparing fixed length fields such as phone and
social security numbers.
ind_c[1] All lower case characters are converted to upper case prior
to the comparison. Disabling this feature means that the lower
case string "code" will not be recognized as the same as the
upper case string "CODE". Also, the adjustment for similar
characters section only applies to uppercase characters.
The suggested values are all zeros for character strings such as names.*/
staticintpass=0,adjwt[91][91];
staticcharsp[39][2] =
{'A','E','A','I','A','O','A','U','B','V','E','I','E','O','E','U',
'I','O','I','U','O','U','I','Y','E','Y','C','G','E','F',
'W','U','W','V','X','K','S','Z','X','S','Q','C','U','V',
'M','N','L','I','Q','O','P','R','I','J','2','Z','5','S',
'8','B','1','I','1','L','0','O','0','Q','C','K','G','J',
'E',' ','Y',' ','S',' '};
charying_hold[MAX_VAR_SIZE],
yang_hold[MAX_VAR_SIZE],
ying_flag[MAX_VAR_SIZE],
yang_flag[MAX_VAR_SIZE];
double weight,Num_sim;
longminv,search_range,lowlim,ying_length,
hilim, N_trans,Num_com,yang_length;
intyl1,yi_st,N_simi;
registerinti,j,k;
/* Initialize the adjwt array on the first call to the function only.
The adjwt array is used to give partial credit for characters that
may be errors due to known phonetic or character recognition errors.
A typical example is to match the letter "O" with the number "0"*/
if (!pass){
pass++;
for (i=0; i<91; i++)for (j=0; j<91; j++) adjwt[i][j] = 0;
for (i=0; i<36; i++){
adjwt[sp[i][0]][sp[i][1]] = 3;
adjwt[sp[i][1]][sp[i][0]] = 3;
}}
/* Identify the strings to be compared by stripping off all leading and
trailing spaces.*/
k = y_length - 1;
for(j = 0;((ying[j]==' ') && (j < k));j++);
for(i = k;((ying[i]==' ') && (i > 0));i--);
ying_length = i + 1 - j;
yi_st = j;
for(j = 0;((yang[j]==' ') && (j < k));j++);
for(i = k;((yang[i]==' ') && (i > 0));i--);
yang_length = i + 1 - j;
ying_hold[0]=yang_hold[0]=0;
strncat(ying_hold,&ying[yi_st],ying_length);
strncat(yang_hold,&yang[j],yang_length);
if (ying_length > yang_length){
search_range = ying_length;
minv = yang_length;
}
else{
search_range = yang_length;
minv = ying_length;
}
/* If either string is blank - return*/
if (!minv)return(0.0);
/* Blank out the flags*/
ying_flag[0] = yang_flag[0] = 0;
strncat(ying_flag,NULL60,search_range);
strncat(yang_flag,NULL60,search_range);
search_range = (search_range/2) - 1;
/* Convert all lower case characters to upper case.*/
if (!ind_c[1]){
for (i = 0;i < ying_length;i++)if (islower(ying_hold[i])) ying_hold[i] -= 32;
for (j = 0;j < yang_length;j++)if (islower(yang_hold[j])) yang_hold[j] -= 32;
}
/* Looking only within the search range, count and flag the matched pairs.*/
Num_com = 0;
yl1 = yang_length - 1;
for (i = 0;i < ying_length;i++){
lowlim = (i >= search_range) ? i - search_range : 0;
hilim = ((i + search_range) <= yl1) ? (i + search_range) : yl1;
for (j = lowlim;j <= hilim;j++){
if ((yang_flag[j] !='1') && (yang_hold[j] == ying_hold[i])){
yang_flag[j] ='1';
ying_flag[i] ='1';
Num_com++;
break;
}}}
/* If no characters in common - return*/
if (!Num_com)return(0.0);
/* Count the number of transpositions*/
k = N_trans = 0;
for (i = 0;i < ying_length;i++){
if (ying_flag[i] =='1'){
for (j = k;j < yang_length;j++){
if (yang_flag[j] =='1'){
k = j + 1;
break;
}}
if (ying_hold[i] != yang_hold[j]) N_trans++;
}}
N_trans = N_trans / 2;
/* adjust for similarities in nonmatched characters*/
N_simi = 0;
if (minv > Num_com){
for (i = 0;i < ying_length;i++){
if (ying_flag[i] ==' ' && INRANGE(ying_hold[i])){
for (j = 0;j < yang_length;j++){
if (yang_flag[j] ==' ' && INRANGE(yang_hold[j])){
if (adjwt[ying_hold[i]][yang_hold[j]] > 0){
N_simi += adjwt[ying_hold[i]][yang_hold[j]];
yang_flag[j] ='2';
break;
}}}}}}
Num_sim = ((double) N_simi)/10.0 + Num_com;
/* Main weight computation.*/
weight= Num_sim / ((double) ying_length) + Num_sim / ((double) yang_length)
+ ((double) (Num_com - N_trans)) / ((double) Num_com);
weight = weight / 3.0;
/* Continue to boost the weight if the strings are similar*/
if (weight > 0.7){
/* Adjust for having up to the first 4 characters in common*/
j = (minv >= 4) ? 4 : minv;
for (i=0;((i<j)&&(ying_hold[i]==yang_hold[i])&&(NOTNUM(ying_hold[i])));i++);
if (i) weight += i * 0.1 * (1.0 - weight);
/* Optionally adjust for long strings. */
/* After agreeing beginning chars, at least two more must agree and
the agreeing characters must be > .5 of remaining characters. */
if ((!ind_c[0]) && (minv>4) && (Num_com>i+1) && (2*Num_com>=minv+i))
if (NOTNUM(ying_hold[0]))
weight += (double) (1.0-weight) *
((double) (Num_com-i-1) / ((double) (ying_length+yang_length-i*2+2)));
}
return(weight);
}/* strcmp95 */
