I'm very new to Java and I don't understand why the value of the variable "A" changes when passed as argument to a function. I do change it's value in the function but I think this shouldn't be a problem since the function creates its own "copy" of the argument. My project consists of a main function and a class in which my functions are declared and implemented as shown below.
package NewtonRapson;
public class Main {
public static void main(String[] args) {
division2 d2 = new division2();
double A[] = {1, -2, 0, 7};
double B[] = {0,1,1};
double D[];
double res = 0;
d2.imprimir(A);
res = d2.p_eval (A, 0.707);
System.out.println();
System.out.println( res);
d2.p_div(A,B);
d2.imprimir(A);
res = d2.p_eval (A, 0.707);
System.out.println();
System.out.println( res);
}
}
`
package NewtonRapson;
public class division2 {
int grado(double A[]){
int grado = A.length -1;
int cont = 0;
for (int i = (A.length - 1); i>= 0; i--){
if (A[i] != 0){break;}
if (A[i] == 0){ cont++; }
}
return grado - cont;
}
double [] incrementar_grado(double A[], int k){
double r[] = new double[A.length];
for (int i = 0; i < A.length; i++){
r[i] = 0;
}
for (int i = 0; i < A.length; i++){
if (i+k < A.length){
r[i+k] = A[i];
}
}
return r;
}
double [] p_div(double A[], double B[]){
double cte;
double C[] = new double[A.length];
while (grado(A) >= grado(B)){
for(int i = 0; i < C.length; i++){
C[i] = 0;
}
cte = A[grado(A)] / B[grado(B)];
for(int i = 0; i < C.length; i++){
if(i >= B.length) break;
C[i] = -cte*B[i];
}
for(int i = 0; i < C.length; i++){
if (grado (A) > grado (C)){
C = incrementar_grado( C, grado(A)-grado(C) );
}
A[i] = A[i]+C[i];
}
}
double res[] = new double[grado(A) + 1];
for (int i =0; i< res.length; i++){
res [i] = A[i];
}
return res;
}
double p_eval(double A[], double x) {
double res = 0;
for (int i = 0; i < A.length; i++) {
res = res + A[i] * Math.pow(x, i);
}
return res;
}
void imprimir(double A[]){
System.out.println();
for(int i=0;i<A.length;i++){
//System.out.println( dividir(polinomio,d)[i] );
System.out.print( A[i] );
System.out.print(" | ");
}
}
double [] p_derivar(double A[] ) {
double d[] = new double [grado(A)];
for(int i=0;i< d.length; i++){
d[i]= A[i+1] * (i+1);
}
return d;
}
}
The reason as to why A changes its value still remains unknown to me.
