In order to explain the answer to your query, I will provide a detailed explanation with examples.
The statement “per-column arrays must each be 1-dimensional” typically refers to the requirement in certain programming languages or data manipulation systems where data stored in columns should be represented as 1-dimensional arrays or vectors. This requirement ensures consistent data structure for ease of processing and analysis.
Let’s take an example to illustrate this concept:
Suppose you have a dataset that contains information about students, with columns representing different attributes such as ‘Name’, ‘Age’, and ‘Grade’. If you were to represent this dataset as an array, each attribute would correspond to a column.
const students = [
['John', 'Mary', 'Alex'],
[18, 19, 17],
['A', 'B', 'C']
];
In the above example, we have three columns: ‘Name’, ‘Age’, and ‘Grade’. Each of these columns is represented as a separate 1-dimensional array.
For instance, the ‘Name’ column is represented as [‘John’, ‘Mary’, ‘Alex’]. It is a 1-dimensional array where each element corresponds to the name of a student.
Similarly, the ‘Age’ column is represented as [18, 19, 17], and the ‘Grade’ column is represented as [‘A’, ‘B’, ‘C’].
By organizing data in this manner, it becomes easier to perform operations on specific columns or iterate over them individually.
However, if you were to violate the requirement of having each column represented as a 1-dimensional array, it can lead to complications and errors in data processing or analysis.