FILE* file = fopen( "data.txt", "w" );
char buf[ 256 ];
double w[ 100 ] = { 0.1 , 0.5 , 0.32 ,0.65 , 0.76 , -0.45 };
for( int i = 0; i < 10; i ++ )
{
　　sprintf( buf, "%f\n", w[ i ] );
　　fputs( buf, file );
}
fclose( file );