offset

Detecting offset of an element on scroll in javascript / jQuery

由 血红的双手。 提交于 2019-12-04 08:31:49
问题 I am looking looking to calculate the distance between an element and the top of the document window. On scroll I am able to get the initial value but it does not change. How can I find this value and what the number has changed to on scroll? JS: $(function() { $(window).scroll(function() { var h1 = $("h1"); console.log(h1.offset().top) }); }); HTML: <div id="cover"> <h1>hello sir</h1> </div> 回答1: Compare the offset of the <h1> element to how far down the page the user has scrolled. The $

Formula/algorithm to offset GPS coordinations

由 為{幸葍}努か 提交于 2019-12-04 06:24:18
问题 I have GPS coordinates provided as degrees latitude, longitude and would like to offset them by a distance and an angle. E.g.: What are the new coordinates if I offset 45.12345 , 7.34567 by 22km along bearing 104 degrees ? Thanks 回答1: For most applications one of these two formulas are sufficient: "Lat/lon given radial and distance" The second one is slower, but makes less problems in special situations (see docu on that page). Read the introduction on that page, and make sure that lat/lon

How to read files with an offset from Hadoop using Java

由 一个人想着一个人 提交于 2019-12-04 05:17:10
Problem: I want to read a section of a file from HDFS and return it, such as lines 101-120 from a file of 1000 lines. I don't want to use seek because I have read that it is expensive. I have log files which I am using PIG to process down into meaningful sets of data. I've been writing an API to return the data for consumption and display by a front end. Those processed data sets can be large enough that I don't want to read the entire file out of Hadoop in one slurp to save wire time and bandwidth. (Let's say 5 - 10MB) Currently I am using a BufferedReader to return small summary files which

关于scroll,client,innear,avail,offset等的理解

由 廉价感情. 提交于 2019-12-04 04:49:19
在写实例理解scrollWidth，clientWidth，innearWidth，availWidth及offsetWidth等的时候，意外的又发现了margin值合并的问题，在这里同时记录下 1.偏移量的区别 html文件（自己写的示例） <div id="root"> <div class="box"> <div class="content"></div> </div> </div> css样式 <style> body, html{ padding: 0; margin: 0; } #root{ /*position: relative;*/ margin: 0 auto; width: 1200px; /*border: 1px solid black;*/ } .box{ overflow: scroll; margin: 5px; padding: 20px; width: 500px; height: 600px; border: 2px solid blueviolet; /*box-sizing: border-box;*/ background: linear-gradient(to right, rgb(85, 181, 255), rgb(207, 224, 232)); } .content{ width: 530px; height: 600px;

Flink读写Kafka

由 邮差的信 提交于 2019-12-04 03:27:32
/*--> */ /*--> */ Flink 读写 Kafka 在 Flink 中，我们分别用 Source Connectors 代表连接数据源的连接器，用 Sink Connector 代表连接数据输出的连接器。下面我们介绍一下 Flink 中用于读写 kafka 的 source & sink connector 。 Apache Kafka Source Connectors Apache Kafka 是一个分布式的流平台，其核心是一个分布式的发布 - 订阅消息系统，被广泛用于消费与分发事件流。 Kafka 将事件流组织成为 topics 。一个 topic 是一个事件日志（ event-log ），保证读入事件的顺序为事件写入的顺序。为了实现可扩展， topic 可以被分为多个 partition ，并分布在集群中的各个节点中。但是在 topic 分区后，由于 consumers 可能会从多个 partition 读入数据，所以此时只能在 partition 级别保证事件的顺序。在 Kafka 中，当前读的位置称为偏移量（ offset ）。 可以通过 sbt 或 maven 构建 Flink Kafka connector 的依赖，下面是一个 sbt 的例子： // https://mvnrepository.com/artifact/org.apache.flink

Selecting a Specific Column of a Named Range for the SUMIF Function

由 眉间皱痕 提交于 2019-12-04 01:18:11
I am trying to create a SUMIF function that dynamically adds up values in a specific column of a named range in my Excel sheet. It is very easy to do this when there is no named range : The formula picks out all the cells that contain "London" in their name and sums up the expenses related to London. What I am trying to do is to use a named range called TripsData (A2:B5) and tell the SUMIF function to sum the entries in the column 2 of this range that meet the criterion of having London in their name. How can I make this work without needing to create a second named range for column 2 and

rough estimate of the time offset from GMT from latitude longitude

由 南笙酒味 提交于 2019-12-04 00:41:46
Is there a way to estimate the offset from GMT (or time zone) from a latitude/longitude? I've seen geonames, but this would need to work long term and we don't really want to rely on a web service. It'd just be used for determining whether to display "today" or "tonight" when giving information to various users so it wouldn't need to be too accurate (an hour or two off wouldn't be bad). offset = direction * longitude * 24 / 360 where direction is 1 for east, -1 for west, and longitude is in (-180,180) James D Basing the time zone on the longitude alone is wildly inaccurate outside of

深入理解Kafka必知必会（上）

由 这一生的挚爱 提交于 2019-12-03 23:48:24
Kafka的用途有哪些？使用场景如何？ 消息系统： Kafka 和传统的消息系统（也称作消息中间件）都具备系统解耦、冗余存储、流量削峰、缓冲、异步通信、扩展性、可恢复性等功能。与此同时，Kafka 还提供了大多数消息系统难以实现的消息顺序性保障及回溯消费的功能。 存储系统： Kafka 把消息持久化到磁盘，相比于其他基于内存存储的系统而言，有效地降低了数据丢失的风险。也正是得益于 Kafka 的消息持久化功能和多副本机制，我们可以把 Kafka 作为长期的数据存储系统来使用，只需要把对应的数据保留策略设置为“永久”或启用主题的日志压缩功能即可。 流式处理平台： Kafka 不仅为每个流行的流式处理框架提供了可靠的数据来源，还提供了一个完整的流式处理类库，比如窗口、连接、变换和聚合等各类操作。 Kafka中的ISR、AR又代表什么？ISR的伸缩又指什么 分区中的所有副本统称为 AR（Assigned Replicas）。所有与 leader 副本保持一定程度同步的副本（包括 leader 副本在内）组成ISR（In-Sync Replicas），ISR 集合是 AR 集合中的一个子集。 ISR的伸缩： leader 副本负责维护和跟踪 ISR 集合中所有 follower 副本的滞后状态，当 follower 副本落后太多或失效时，leader 副本会把它从 ISR 集合中剔除。如果

kafka-clients 1.0 高阶API消费消息(未完)

由 孤人 提交于 2019-12-03 21:21:31
消费消息的请求(按序) org/apache/kafka/common/requests/RequestHeader org/apache/kafka/common/requests/ApiVersionsRequest org/apache/kafka/common/requests/MetadataRequest 批量查询topic的元数据信息 org/apache/kafka/common/requests/FindCoordinatorRequest 从拿到的topic的元数据中取出leader节点 作为组协调者 org/apache/kafka/common/requests/JoinGroupRequest org/apache/kafka/common/requests/SyncGroupRequest org/apache/kafka/common/requests/OffsetFetchRequest org/apache/kafka/common/requests/ListOffsetRequest org/apache/kafka/common/requests/FetchRequest org/apache/kafka/common/requests/HeartbeatRequest 请求接口文档参考 响应接口文档参考 RequestHeader 请求头

offset range 查询

由 别说谁变了你拦得住时间么 提交于 2019-12-03 21:19:27
offset range 查询 我们在实际使用过程中经常需要查询某个topic的某分区的offset的range 命令行： kafka-run-class.sh kafka.tools.GetOffsetShell --broker-list xxxx:9092 -topic xxxtopic --time -2 kafka-run-class.sh kafka.tools.GetOffsetShell --broker-list xxxx:9092 -topic xxxtopic --time -1 -1 -2 的特殊含义： public class ListOffsetRequest extends AbstractRequest { public static final long EARLIEST_TIMESTAMP = -2L; public static final long LATEST_TIMESTAMP = -1L; } 客户端 KafkaConsumer.endOffsets(Collection ) KafkaConsumer.beginningOffsets(Collection ) Fetcher.beginningOrEndOffset(Collection , long, long) Fetcher.retrieveOffsetsByTimes(Map
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