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Subsets of data can be selected by column name, index, or Boolean expressions. For example, df[df['col1'] > 5] will return all rows in the DataFrame df for which the value of the column col1 exceeds 5. [4]: 126–128 Data can be grouped together by a column value, as in df['col1'].groupby(df['col2']), or by a function which is applied to the index.
Alpha-renaming can make static code analysis easier since only the alpha renamer needs to understand the language's scoping rules. For example, in this code: class Point { private : double x , y ; public : Point ( double x , double y ) { // x and y declared here mask the privates setX ( x ); setY ( y ); } void setX ( double newx ) { x = newx ...
The C standard library provides a function called rename which does this action. [1] In POSIX, which is extended from the C standard, the rename function will fail if the old and new names are on different mounted file systems. [2] In SQL, renames are performed by using the CHANGE specification in ALTER TABLE statements.
Early out-of-order machines did not separate the renaming and ROB/PRF storage functions. For that matter, some of the earliest, such as Sohi's RUU or the Metaflow DCAF, combined scheduling, renaming, and storage all in the same structure. Most modern machines do renaming by RAM indexing a map table with the logical register number.
In relational algebra, a rename is a unary operation written as / where: . R is a relation; a and b are attribute names; b is an attribute of R; The result is identical to R except that the b attribute in all tuples is renamed to a. [1]
The Church numeral n is a function that takes a function f as argument and returns the n-th composition of f, i.e. the function f composed with itself n times. This is denoted f ( n ) and is in fact the n -th power of f (considered as an operator); f (0) is defined to be the identity function.
dplyr is an R package whose set of functions are designed to enable dataframe (a spreadsheet-like data structure) manipulation in an intuitive, user-friendly way. It is one of the core packages of the popular tidyverse set of packages in the R programming language. [1]
First-generation (vacuum tube-based) electronic digital computer. 1961 $18.672B: $190.38B A basic installation of IBM 7030 Stretch had a cost at the time of US$7.78 million each. The IBM 7030 Stretch performs one floating-point multiply every 2.4 microseconds. [78] Second-generation (transistor-based) computer. 1964 $2.3B: $22.595B