conditional-statements

问题 I am adding a new protocol to Scapy and I am having difficulties with a concrete field. This field specifies the length of a package payload. The field can be 1, 2, 3 or 4 bytes long depending on the length of the payload. Additionally, it is encoded. The way I found to determine if the size of the field is 1, 2, 3 or 4 bytes, is taking the first byte of the value and if it is less than 127 the field is represented by 1 byte, if it is more than 127 and less than x it is represented by 2 bytes

问题 I want to read event entries from a certain custom event log at c# program, And to filter them by their description. Is there a way to do it? Or a way to get the entries as collection so I will be able to select from that by condition? 回答1: Try something like this: string queryString = string.Format("*[System[TimeCreated[@SystemTime>='{0}' and @SystemTime<='{1}']]]", DateTime.Now.Date.AddDays(-10).ToString("s"), DateTime.Now.Date.ToString("s")); var q = new EventLogQuery("Microsoft-Windows

问题 To my knowledge, C++ always evaluates from left to right in a conditional statement if(A, B, C) A would be evaluated first, B second, so on. However, the following example is exhibiting some odd behavior. #include <iostream> #include <map> #include <memory> #include <vector> #include <boost/logic/tribool.hpp> //-//////////////////////////////////////////// // File Block class FileBlock { public: FileBlock(); virtual ~FileBlock(); bool linked(); std::vector<int> messages_; private: boost:

问题 Let's say I have a SQL statement like this that checks a user login: SELECT * FROM users WHERE username='test@example.com', password='abc123', expire_date>=NOW(); Is there a way in SQL to determine specifically which WHERE conditions fail, without having to separate each condition into its own query and test individually? In this specific example it would allow the developer to tell users exactly the reason why their attempt to login failed. For my purposes I'm using PHP/MySQL. 回答1: Well, one

问题 Given the following data frame: import pandas as pd d=pd.DataFrame({'label':[1,2,2,2,3,4,4], 'values':[3,5,7,2,5,8,3]}) d label values 0 1 3 1 2 5 2 2 7 3 2 2 4 3 5 5 4 8 6 4 3 I know how to count the unique values like this: d['dup']=d.groupby('label')['label'].transform('count') Which results in: label values dup 0 1 3 1 1 2 5 3 2 2 7 3 3 2 2 3 4 3 5 1 5 4 8 2 6 4 3 2 But what I would like is a column to have the following values: 1 if there is 1 unique row per the label column, 2 if there

问题 I'm quite new to matlab, and I'm curious how to do this: I have a rather large (27000x11) matrix, and the 8th column contains a number which changes sometimes but is constant for like 2000 rows (not necessarily consecutive). I would like to calculate the mean of the entries in the 3rd column for those rows where the 8th column has the same value. This for each value of the 8th column. I would also like to plot the 3rd column's means as a function of the 8th column's value but that I can do if

问题 I have something like ( COMPLEX_EXPRESSION_N stands for a long subquery) select ID_Operation, FirstCheck = CASE WHEN (COMPLEX_EXPRESSION_1)= 0 then 0 else 1 end, SecondCheck = CASE WHEN (COMPLEX_EXPRESSION_2)= 0 then 0 else 1 end, ThirdCheck = CASE WHEN (COMPLEX_EXPRESSION_3)= 0 then 0 else 1 end, AllChecksOk = Case WHEN (FirstCheck + SecondCheck + Third CHeck = 3) Then 'OK' Else 'No' End from AllOperationsTable Is it possible to use FirstCheck, SecondCheck, ThirdCheck as I did in the

问题 I would like to realize if condition in armv8 NEON inline assembly code. In armv7 this was possible through checking overflow bit like this: VMRS r4, FPSCR BIC r4, r4, #(1<<27) VMSR FPSCR, r4 vtst.16 d30, d30, d30 vqadd.u16 d30, d30, d30 vmrs r4, FPSCR tst r4, #(1<<27) bne label1 But I am not able to achieve this in armv8 equivalent code. It seems that SQADD doesnt affect overflow bit in FPSR or I cannot check it like this. Is it possible or is there better approach how to skip long part of

问题 I am working with GPS data and trying to figure out how to average the 11th-15th fixes for latitude and longitude. I have seen solutions in similar questions for how to average every n rows. The problem is that occasionally the satellites bomb out and the fixes stop at 13 or 14. So, in these cases, I only want to average 3 or 4 values instead of 5. So I am looking to average values for latitude and longitude starting from where the number in series is 11 until the number in series drops again

问题 As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance. Closed 6 years ago . I need suggestion for the right approach to apply conditions in Java. I have 100 conditions based on which I have to change value of a