Count2的含义为:每经过系统内的一个时钟周期,count1位置那里就加1,直到call system_clock(count2,count_rate,count_max)时,此时返回给count2的值就是count1累加时钟个数后返回的值,所以count2不是真实的时间,(count2-count1)表示该段时间内的时钟数。所以运行耗费的时间应该是(count2-count1)/count_rate,单位...
call system_clock(count [, count_rate] [, count_max])从系统时钟获取当前时间,count为整型变量,存储当天时间到毫秒。如果要计算长时间运行的程序时间,则需要添加count_max参数来增大统计上限或者改用data_and_time 结语 这只是统计运行时间的一种简单实现方法,但可以满足我的需求,更优的方法还有待摸索! 参考资...
system_clock用于决定处理器时钟周期.count_rate用于决定每秒CPU的时钟计数,PROGRAM test_system_clockINTEGER ::count,count_rate,count_maxCALL SYSTEM_CLOCK(count,count_rate,count_max)WRITE(*,*) count,count_rate,count_maxEND PROGRAM 解析看不懂?免费查看同类题视频解析查看解答...
=== call system_clock(count=stop_count) !=== print*, ' system clock time : ', real(max(stop_count - start_count , 1_8 )) /real(rate),' seconds' print*, ' kind type start_count : ', kind(start_count) print*, ' kind type stop_count : ', kind(stop...
system_clock用于决定处理器时钟周期.count_rate用于决定每秒CPU的时钟计数,PROGRAM test_system_clockINTEGER ::count,count_rate,count_maxCALL SYSTEM_CLOCK(count,count_rate,count_max)WRITE(*,*) count,count_rate,count_maxEND PROGRAM 解析看不懂?免费查看同类题视频解析查看解答...
call system_clock(t1) call system_clock(count=ic, count_rate=crate, count_max=cmax) call system_clock(count=ic2, count_rate=crate2, count_max=cmax2) call system_clock(count=ic4, count_rate=crate4, count_max=cmax4) call system_clock(t2) print *, t1, t2 print *, ic, crate, cm...
system_clock用于决定处理器时钟周期。count_rate用于决定每秒CPU的时钟计数,PROGRAM test_system_clock INTEGER :: count, count_rate, count_max CALL SYSTEM_CLOCK(count, count_rate, count_max)WRITE(*,*) count, count_rate, count_max END PROGRAM 摘自 http://gcc.gnu.org/onlinedocs/...
Fortran计时函数库:Fortran中常用的计时函数库包括SYSTEM_CLOCK和CPU_TIME。SYSTEM_CLOCK函数返回一个整数值,表示从某个固定时间点开始的CPU时钟周期数。CPU_TIME函数返回一个实数值,表示程序执行的CPU时间。可以根据具体需求选择适合的函数库。 Fortran计时示例代码: ...
call cpu_time(start) do i = 1, n c(i) = a(i) + b(i) end do call cpu_time(end) print *, 'Manual loop computation time:', end - start contains subroutine cpu_time(time) real, intent(out) :: time call system_clock(count, count_rate) ...
When timing a FORTRAN program i usually just use the command call cpu_time(t). Then i stumbled across call system_clock([count,count_rate,count_max]) which seems to do the same thing. However, in a more difficult manor. My knowledge of these come from: Old Intel documentation...