我有阵列：
time Mx My Mz set_nbr group_min
##1 90.000 0.0105615570 0.0128378518 0.92123599 1 1
##2 4990.909 0.0096134025 0.0117695944 0.78439667 1 1
##3 9891.818 0.0093581318 0.0115742493 0.72867894 1 1
##4 14792.727 0.0031807426 0.0113173105 0.55464140 1 1
##5 19693.636 0.0023569651 0.0089484378 0.42502936 1 1
##6 24594.545 0.0008941874 0.0058824078 -0.04729751 1 1
##7 29495.455 -0.0043247786 0.0021214525 -0.13068103 1 1
##8 34396.364 -0.0070967748 0.0011887832 -0.20001126 1 1
##9 39297.273 -0.0086446611 -0.0009107974 -0.22002091 1 1
##10 44198.182 -0.0087562698 -0.0035490228 -0.30663302 1 1
##11 49099.091 -0.0094095244 -0.0156822550 -0.33245014 1 1
##12 54000.000 -0.0123935570 -0.0190667519 -0.34929570 1 1
time Mx My Mz set_nbr group_max
##13 90.000 0.0105615570 0.0128378518 0.92123599 1 3
##14 4990.909 0.0096134025 0.0117695944 0.78439667 1 3
##15 9891.818 0.0093581318 0.0115742493 0.72867894 1 3
##16 14792.727 0.0031807426 0.0113173105 0.55464140 1 3
##17 19693.636 0.0023569651 0.0089484378 0.42502936 1 3
##18 24594.545 0.0008941874 0.0058824078 0.04729751 1 3
##19 29495.455 -0.0043247786 0.0021214525 0.13068103 1 3
##20 34396.364 -0.0070967748 0.0011887832 -0.20001126 1 3
##21 39297.273 -0.0086446611 -0.0009107974 -0.22002091 1 3
##22 44198.182 -0.0087562698 -0.0035490228 -0.30663302 1 3
##23 49099.091 -0.0094095244 -0.0156822550 -0.33245014 1 3
##24 54000.000 -0.0123935570 -0.0190667519 -0.34929570 1 3
> set_nbr 2 group_min
group_max
> set_nbr 3 group_min
group_max
..
我打算计算长度大于或等于2的连续链中包含的元素 Rows <- x[ceiling(x$Mz-y$Mz)==0,]
的数量。在示例中，我有三个链，但我只想要计算其中两个。总的来说应该是5。
答案 0 :(得分：0)
查找＆＃39; CA＆＃34;
的连续链$count = 0;
$link = array(); // Here will be chain lengths
array_push($types, ''); // to work if the last item == 'CA'
foreach($types as $item)
if ($item == 'CA') $count++;
else if ($count)
{ $link[] = $count; $count = 0; }
rsort($link); // 3, 2, 1
$sum = 0;
foreach ($link as $i)
if ($i >= 2) $sum += $i; // Count result
else break; // Further chains are shorter than we want
echo $sum;