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1 编译(保留了C和python语言,简化编译): # ./configure --without-java --without-cpp --without-php --without-erlang #make && make install 2 安装python thrift模块 #easy_... 阅读全文
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001 对文件某一列求和 awk '{sum += $collum};END {print sum}' /path/to/your/file2 33 5假设文件内容如上所示: # awk '{sum += $1};END {print sum}' the-file.txt 5# awk '... 阅读全文
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Shannon entropy is one of the most important metrics in information theory. Entropy measures the uncertainty associated with a random variable, i.e.... 阅读全文
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Definition Let be a sequence of (complex) Hilbert spaces and be the bounded operators from Hi to Hj. A map A on where is called a positive d... 阅读全文
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Definition A Hilbert space H is a real or complex inner product space that is also a complete metric space with respect to the distance function... 阅读全文
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In linear algebra, a symmetric n × n real matrix M is said to be positive definite if zTMz is positive for every non-zero columnvector z of n re... 阅读全文
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001 创建项目 mvn archetype:generate -DgroupId=com.company.push.monitor -DartifactId=push-monitor -DarchetypeArtifactId=maven-archetype-quickstart -Dinte... 阅读全文
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1) 使用MVN创建项目 mvn archetype:generate -DgroupId=com.mycompany.app -DartifactId=my-app -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMo... 阅读全文
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The storage wars: Shadow Paging, Log Structured Merge and Write Ahead Logging previous: Seek, and you shall find, or maybe delay a lot next: N... 阅读全文
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原文请点这里 在MySQL中有两种方法可以删除数据,一种是DELETE语句,另一种是TRUNCATE TABLE语句。DELETE语句可以通过WHERE对要删除的记录进行选择。而使用TRUNCATE TABLE将删除表中的所有记录。因此,DELETE语句更灵活。 如果要清空表中的所有记录... 阅读全文