# Exponential function giving different results

• October 14th, 2013, 09:20 PM
Rini
Exponential function giving different results
Hi,

I have an n by 2 array ppi having integer values(having duplicate) a second array n by 1 gid containing unique integer values from ppi and a third array X0 with 0 and 1 values. Below is a MATLAB code which I want to implement in Java-

MATLAB version-

gamma0 = 10; gamma1 = 10; beta = 20;
delta = 0;
for i=1:length(gid)
gconn = union(ppi(find(ppi(:,1)==gid(i)),2), ppi(find(ppi(:,2)==gid(i)),1));
[a,b] = intersect(gid, gconn);
u1 = (X0(i)*weight + sum(X0(b)==1))/(weight+length(gconn));
u0 = ((1-X0(i))*weight + sum(X0(b)==0))/(weight+length(gconn));
UU1(i) = u1;
UU0(i) = u0;
mrfpdf(i) = exp((1-X0(i))*(gamma0-beta*u1)+X0(i)*(gamma1-beta*u0))/(exp(gamma0-beta*u1)+exp(gamma1-beta*u0));
end

Java version method

double[] mrfpdf = new double[X0.length];
Integer[] X = new Integer[X0.length];
;
// find out unique class labels in ppi
for (int i = 0; i < ppi.length; i++) {
for (int j = 0; j < ppi[0].length; j++) {
}
}
System.out.println("unique gid_set: " + gid_set);
Double[] gid = gid_set.toArray(new Double[gid_set.size()]);
Arrays.sort(gid);

int gamma0 = 10, gamma1 = 10, beta = 20, delta = 0;
for (int i = 0; i < gid.length; i++) {

Set<Double> ppi1 = new HashSet<Double>();
Set<Double> ppi2 = new HashSet<Double>();
for (int k = 0; k < ppi.length; k++) {
if (ppi[k][0] == gid[i])

if (ppi[k][1] == gid[i])

}

Set<Double> gconn = new HashSet<Double>(ppi1);
Set<Double> a = new HashSet<Double>(gid_set);
a.retainAll(gconn);
int[] b = new int[a.size()];
int x = 0;
for (double j : a) {
for (int c = 0; c < gid.length; c++) {
if (j == gid[c]) {
b[x] = c;
x++;
}
}
}
java.util.List<Double> X0_list = new ArrayList<Double>();
for (double z : X0) {
}
int sum1 = 0;
for (int y : b) {
if (X0_list.get(y) == 1)
sum1++;
}
int sum2 = 0;
for (int y : b) {
if (X0_list.get(y) == 0)
sum2++;
}
u1 = (int) ((X0[i] * weight + sum1) / (weight + gconn.size()));
u0 = (int) (((1 - X0[i]) * weight + sum2) / (weight + gconn.size()));
UU1[i] = u1;
UU0[i] = u0;
mrfpdf[i] = (Math.exp((1 - X0[i]) * (gamma0 - beta * u1) + X0[i]* (gamma1 - beta * u0)) / (Math.exp(gamma0 - beta * u1) + Math.exp(gamma1 - beta * u0)));

}// end for(int i : gid)
}

Can someone please tell me why the values in mrfpdf array is different in Java and Matlab codes? Java code results in 0.99 and 0.5 values whereas Matlab does not produce 0.5

Thanks