en	Statistics
zh-hans	统计信息

en	:idprefix: stats_

en	Open-addressing and concurrent containers can be configured to keep running statistics of some internal operations affected by the quality of the supplied hash function.
zh-hans	开放寻址和并发容器可配置为持续统计受所提供哈希函数质量影响的某些内部操作。

en	Synopsis
zh-hans	概要

en	__stats-summary-type__
zh-hans	_统计摘要类型_

en	Provides the average value, variance and standard deviation of a sequence of numerical values.
zh-hans	提供数值序列的平均值、方差和标准差。

en	__insertion-stats-type__
zh-hans	_插入统计类型_

en	Provides the number of insertion operations performed by a container and statistics on the associated __probe length__ (number of xref:structures.adoc#structures_open_addressing_containers[bucket groups] accessed per operation).
zh-hans	提供容器执行的插入操作次数及相关__探查长度__（每次操作访问的 xref:structures.adoc#structures_open_addressing_containers[桶组] 数量）的统计信息。

en	__lookup-stats-type__
zh-hans	_查找统计类型_

en	For successful (element found) or unsuccessful (not found) lookup, provides the number of operations performed by a container and statistics on the associated __probe length__ (number of xref:structures.adoc#structures_open_addressing_containers[bucket groups] accessed) and number of element comparisons per operation.
zh-hans	对于成功（找到元素）或失败（未找到）查找操作，提供容器执行的操作次数及相关__探查长度__（访问的 xref:structures.adoc#structures_open_addressing_containers[桶组] 数量）和每次操作的元素比较次数的统计信息。

en	__stats-type__
zh-hans	_stats-type_

en	Provides statistics on insertion, successful and unsuccessful lookups performed by a container. If the supplied hash function has good quality, then:
zh-hans	提供容器执行的插入操作、成功及失败查找操作的统计信息。若提供的哈希函数质量良好，则：

en	Average probe lenghts should be close to 1.0.
zh-hans	平均探查长度应接近1.0。

en	For successful lookups, the average number of element comparisons should be close to 1.0.
zh-hans	对于成功查找，平均元素比较次数应接近 1.0。

en	For unsuccessful lookups, the average number of element comparisons should be close to 0.0.
zh-hans	对于失败查找，平均元素比较次数应接近 0.0。

en	These statistics can be used to determine if a given hash function can be marked as link:../../../../../container_hash/doc/html/hash.html#ref_hash_is_avalanchinghash[__avalanching__].
zh-hans	这些统计信息可用于判断给定的哈希函数是否可被标记为 link:../../../../../container_hash/doc/html/hash.html#ref_hash_is_avalanchinghash[_雪崩效应_] 。

en	---