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  2. Wide and narrow data - Wikipedia

    en.wikipedia.org/wiki/Wide_and_narrow_data

    The pandas package in Python implements this operation as "melt" function which converts a wide table to a narrow one. The process of converting a narrow table to wide table is generally referred to as "pivoting" in the context of data transformations.

  3. Lookup table - Wikipedia

    en.wikipedia.org/wiki/Lookup_table

    In computer science, a lookup table (LUT) is an array that replaces runtime computation with a simpler array indexing operation, in a process termed as direct addressing.The savings in processing time can be significant, because retrieving a value from memory is often faster than carrying out an "expensive" computation or input/output operation. [1]

  4. List of tz database time zones - Wikipedia

    en.wikipedia.org/wiki/List_of_tz_database_time_zones

    For zones in which Daylight Saving is not observed, the DST offset shown in this table is a simple duplication of the SDT offset. The UTC offsets are based on the current or upcoming database rules. This table does not attempt to document any of the historical data which resides in the database.

  5. Row- and column-major order - Wikipedia

    en.wikipedia.org/wiki/Row-_and_column-major_order

    To use column-major order in a row-major environment, or vice versa, for whatever reason, one workaround is to assign non-conventional roles to the indexes (using the first index for the column and the second index for the row), and another is to bypass language syntax by explicitly computing positions in a one-dimensional array.

  6. Control table - Wikipedia

    en.wikipedia.org/wiki/Control_table

    "CT1" is an example of a control table that is a simple lookup table. The first column represents the input value to be tested (by an implied 'IF input1 = x') and, if TRUE, the corresponding 2nd column (the 'action') contains a subroutine address to perform by a call (or jump to – similar to a SWITCH statement).

  7. Table (database) - Wikipedia

    en.wikipedia.org/wiki/Table_(database)

    External tables (in Informix [3] or Oracle, [4] [5] for example) can also be thought of as views. In many systems for computational statistics, such as R and Python's pandas, a data frame or data table is a data type supporting the table abstraction. Conceptually, it is a list of records or observations all containing

  8. Rijndael S-box - Wikipedia

    en.wikipedia.org/wiki/Rijndael_S-box

    The column is determined by the least significant nibble, and the row by the most significant nibble. For example, the value 9a 16 is converted into b8 16 . The S-box maps an 8-bit input, c , to an 8-bit output, s = S ( c ) .

  9. Pivot table - Wikipedia

    en.wikipedia.org/wiki/Pivot_table

    A pivot table is a table of values which are aggregations of groups of individual values from a more extensive table (such as from a database, spreadsheet, or business intelligence program) within one or more discrete categories. The aggregations or summaries of the groups of the individual terms might include sums, averages, counts, or other ...