Question

i need to implement a project with visual intimacy between persons,can anyone recommends an algorithm for person’s intimacy in phone contact?

intimacy attenuate over time(the intimacy attenuates automatically if you havnt click/dial it for a long time).

Assume in my address book：

Person     Intimacy(0-100%)
   A         40%
   B         80%
   C         10%

A’s intimacy needs raise after i call A ,like this

Person     Intimacy(0-100%)
   A         42%
   B         80%
   C         10%

nothing happens after follow 5 days, A,B,C’s intimacy need decline,like this

Person     Intimacy(0-100%)
   A         37%
   B         78%
   C         8%

thanks for everyone’s answer

Answer 1

intimacy attenuate over time(the intimacy attenuates automatically if you havnt click/dial it for a long time).

You could use an exponential decaying number expressed as a Half Life

double intimacy = Math.pow(0.5, time / halfLife);

I would be surprised if there is a standard solution to your problem.

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A typical graph has a shape like this.

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Are you asking for an algorithm to determine how well you know someone in your address book based on how often you call them?

For this you could use an Exponential Weighted Moving Average Again, I just speculating what might be useful.

could you express more detail?

From the data you gave, the half life is about 28 days. You can use the EWMA on a daily basis like this

double alpha = 1.0/28;

score = (contacted ? 1 : 0) * alpha + score * (1 - alpha); 

e.g.

contacted, prev score, score
TRUE        40%     42%
FALSE       42%     41%
FALSE       41%     39%
FALSE       39%     38%
FALSE       38%     36%
FALSE       36%     35%

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Say the decay is 28 days and I call the same person for 200 days. The score looks like

double score = 0;
double alpha = 1.0 / 28;
boolean contacted = true;
for (int i = 0; i < 200; i++) {
    score = (contacted ? 1 : 0) * alpha + score * (1 - alpha);
    System.out.printf("%.3f%n", score);
}    

prints

0.036
0.070
0.103
... deleted ...
0.999
0.999
0.999

Its not possible for the score to larger than the maximum value (in this case the 1 in the equation).