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This paper introduces Topsis comprehensive evaluation method, illustrates its calculation process through a practical case, and realizes it by using R language. 1. Overview of TOPSIS method The full name of TOPSIS is technology for order preference by similarity to an ideal solution. TOPSIS method was first proposed by C.L.Hwang and K.Yoon ...

1. IO stream object IO: input output IO is used to flow data from one device to another Data files flow from disk to memory, from disk to mobile storage device, and from one computer to another Everything is bytes: any data file is composed of bytes, and bytes are the smallest storage unit in the computer (Java source code, games, music, mov ...

1. Label Mainly use the function geom_text() adds labels at specific x and y coordinates label geom_text() supports modifying most graphic attributes of all geometric objects because there are countless ways to adjust the presentation of text family sets the font. Currently, there are only three general fonts: sans (default), serif and mono S ...

Key points of data mapping 3 - spaghetti map Broken line diagrams with too many lines usually become unreadable. This kind of diagram is generally called spaghetti diagram. Therefore, this kind of chart can hardly provide information about the data. Drawing example Let's take the evolution of female baby names in the United States from 1 ...

Java video tutorialhttps://www.xin3721.com/eschool/Javaxin3721/ When I went to the interview before, I was asked how to solve a spring nested transaction. When asked, I was speechless. It happened that the current project just used nested transactions. Distributed transactions are also being attempted. So now I have learned something about nest ...

1 branch structure Although the program with sequential structure can solve the problems of calculation and output But you can't judge and choose. For the problem of making judgment before selection, we should use the branch structure 1.2 form 1.3.1 exercise: Commodity discount cases Create package: cn.tedu.basic Create class: TestDiscoun ...

1 nested for loop 1.1 general There are at least two for loops. Judge whether the inner layer can be executed according to the conditions of the outer layer If it can be executed, loop the inner layer code, and then continue to judge whether to execute the next loop of the outer layer loop 1.2 nested for m   1.3 exercise: nested for loop ...

1, Simple arithmetic practice 1: Input two variables on the console and exchange the values of these two variables [complete with XOR] #The console inputs two variables and exchanges the values of the two variables #[complete with XOR] print("Please enter a,b Value of: ") a = int(input("Please enter a Value of")) b = int(input("Please enter b ...

introduction After using JDK1.8, most list operations can be written using lamada expressions, which can make the code simpler and develop faster. The following are the common operations of lamada expressions I use in my work on list. I like to collect suggestions. Taking the user table as an example, the user entity code is as follows: public ...

reshape2 is a package written by Hadley Wickham, which can easily convert data between wide and long formats. 1. Length width data format Wide data format Each variable of wide data format corresponds to a column, for example: ## ozone wind temp ## 1 23.61538 11.622581 65.54839 ## 2 29.44444 10.266667 79.10000 ## 3 59.11538 ...