5.2 2次元配列

2次元配列も定義できるようだが、 こちらはカギ括弧 [ ] は使えず、 丸括弧 ( ) を使う必要があるみたい。

2次元配列はこんなふうに

real[int,int] a(2,2);
a(1,1)=1; a(1,2)=2;
a(2,1)=3; a(2,2)=4;

2次元配列の例 (丸い括弧を使う)

// operation_of_2Darray.edp

real[int,int] a(3,2);
a(0,0)=1; a(0,1)=2;
a(1,0)=3; a(1,1)=4;
a(2,0)=5; a(2,1)=6;
cout << "a.n=" << a.n << ", a.m=" << a.m << endl; // 3と2になる。
for (int i=0; i < a.n; i++) {
  for (int j=0; j < a.m; j++)
    cout << setw(4) << a(i,j) << " ";
  cout << endl;
}
cout << "output by \"cout<<\"a=\"<<a<<endl;\"" << endl;
cout << "a=" << a << endl;

cout << "max of a=" << a.max << endl;
cout << "min of a=" << a.min << endl;
cout << "sum of a=" << a.sum << endl;
cout << "1-norm of a=" << a.l1 << endl;
cout << "2-norm of a=" << a.l2 << endl;
cout << "infty-norm of a=" << a.linfty << endl;

2次元配列の例 (丸い括弧を使う)

$ FreeFem++ operation_of_2Darray.edp
-- FreeFem++ v4.14 (Mar 10 déc 2024 18:13:35 CET - git v4.15)
   file : operation_of_2Darray.edp
 Load: lg_fem lg_mesh lg_mesh3 eigenvalue
    1 : // operation_of_2Darray.edp
    2 :
    3 : real[int,int] a(3,2);
    4 : a(0,0)=1; a(0,1)=2;
    5 : a(1,0)=3; a(1,1)=4;
    6 : a(2,0)=5; a(2,1)=6;
    7 : cout << "a.n=" << a.n << ", a.m=" << a.m << endl; // 3と2になる。
    8 : for (int i=0; i < a.n; i++) {
    9 :   for (int j=0; j < a.m; j++)
   10 :     cout << setw(4) << a(i,j) << " ";
   11 :   cout << endl;
   12 : }
   13 : cout << "output by \"cout<<\"a=\"<<a<<endl;\"" << endl;
   14 : cout << "a=" << a << endl;
   15 :
   16 : cout << "max of a=" << a.max << endl;
   17 : cout << "min of a=" << a.min << endl;
   18 : cout << "sum of a=" << a.sum << endl;
   19 : cout << "1-norm of a=" << a.l1 << endl;
   20 : cout << "2-norm of a=" << a.l2 << endl;
   21 : cout << "infty-norm of a=" << a.linfty << endl;
   22 :  sizestack + 1024 =1168  ( 144 )

a.n=3, a.m=2
   1    2
   3    4
   5    6
output by "cout<<"a="<<a<<endl;"
a=3 2
	   1   2
	   3   4
	   5   6

max of a=6
min of a=1
sum of a=21
1-norm of a=21
2-norm of a=9.53939
infty-norm of a=6
times: compile 0.010674s, execution 0.000136s,  mpirank:0
 CodeAlloc : nb ptr  4018,  size :502616 mpirank: 0
Ok: Normal End
$