Matrici

src/Matrici/Matrice.java

@@ -0,0 +1,143 @@
+import java.io.*;
+import java.util.Scanner;
+
+public class Matrice{
+
+    public Matrice(int a, int b){
+        matrice = new double[a][b];
+        this.a=a;
+        this.b=b;
+    }
+
+    public double getElement(int a, int b){
+        return matrice[a][b];
+    }
+
+    public void setElement(int a, int b, double c){
+        this.matrice[a][b]=c;
+    }
+
+    public int getA(){
+        return a;
+    }
+
+    public int getB(){
+        return b;
+    }
+
+    public String toString(){
+        int i, j;
+        String string = "";
+        for(i=0; i<a; i++){
+            string+="|  ";
+            for(j=0; j<b; j++)
+                string+=getElement(i,j) + "  ";
+            string+="|\n";
+        }
+        return string;
+    }
+
+    public void print(PrintStream ps){
+        ps.println(toString());
+    }
+
+    public static Matrice read(Scanner sc) throws Exception{
+        int a, b, i, j;
+        Matrice m1;
+
+        if(!sc.hasNextInt()) return null;
+        a=sc.nextInt();
+        if(!sc.hasNextInt()) return null;
+        b=sc.nextInt();
+
+        m1 = new Matrice(a, b);
+
+        for(i=0; i<a; i++)
+            for(j=0; j<b; j++){
+                if(!sc.hasNextDouble()) return null;
+                m1.setElement(i, j, sc.nextDouble());
+            }
+
+        return m1;
+    }
+
+    private boolean isSummable(Matrice m2){
+        return this.a==m2.getA() && this.b==m2.getB();
+    }
+
+    private boolean isMoltiplicabile(Matrice m2){
+        return getB()==m2.getA();
+    }
+
+    private boolean isSquare(){
+        return this.a==this.b;
+    }
+
+    public boolean equlas(Matrice m2){
+        int i, j;
+        boolean equals = true;
+
+        if(!isSummable(m2)) return false;
+        for(i=0;i<a && equals;i++)
+            for(j=0;j<b && equals;j++)
+                equals &= this.getElement(i, j)==m2.getElement(i, j);
+
+        return equals;
+    }
+
+    public Matrice transposed(){
+        Matrice m2 = new Matrice(b, a);
+        int i, j;
+        for(i=0; i<a; i++)
+            for(j=0; j<b; j++)
+                m2.setElement(j, i, getElement(i, j));
+
+        return m2;
+    }
+
+    /*
+    public static double det(m){
+        if(this.a==2 && this.b==2)
+            return m.getElement(0,0)*m.getElement(1,1)-m.getElement(1,0)*m.getElement(0,1);
+        else{
+
+        }
+
+    }*/
+
+    public Matrice product(Matrice m2){
+        int a=this.a;
+        int b=m2.getB();
+        int c=m2.getA();
+        int i, j, k;
+        double element;
+        Matrice m3 = new Matrice(a, b);
+
+        if(!isMoltiplicabile(m2)) return null;
+
+        for(i=0;i<a;i++)
+            for(j=0;j<b;j++){
+                element=0;
+                for(k=0;k<c;k++)
+                    element+=getElement(i, k)*m2.getElement(k, j);
+                m3.setElement(i, j, element);
+            }
+
+        return m3;
+    }
+
+    public Matrice sum(Matrice m2){
+        Matrice m3 = new Matrice(getA(), getB());
+        int i, j;
+
+        if(!isSummable(m2)) return null;
+        for(i=0; i<getA(); i++)
+            for(j=0; j<getB(); j++)
+                m3.setElement(i, j, getElement(i, j)+m2.getElement(i, j));
+
+        return m3;
+    }
+
+    private double[][] matrice;
+    private int a, b;
+}

src/Matrici/Test.java

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+import java.util.Scanner;
+import java.io.*;
+
+public class Test{
+    public static void main(String [] args) throws Exception{
+        Scanner sc = new Scanner(new File("matrici.dat"));
+        Matrice m = Matrice.read(sc);
+        Matrice m2 = Matrice.read(sc);
+        Matrice m3;
+
+        m3=m.transposed();
+
+        System.out.print("Le matrici m e m3 sono: ");
+        if(m.equals(m3))
+            System.out.println("Uguali\n");
+        else
+            System.out.println("Diverse\n");
+
+        System.out.println("Somma tra m2 e m3");
+        m2.sum(m3).print(System.out);
+
+        System.out.println("Prodotto tra m e m2");
+        m.product(m2).print(System.out);
+    }
+}

src/Matrici/matrici.dat

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+2 3
+1 0 2
+0 3 -1
+3 2
+4 1
+-2 2
+0 3