Array API in D3.js
D3 includes a group of modules. Independently, we can use every module or a group of modules together to implement the operations.
Let’s start.
Introduction to an Array
The array includes the element’s fixed-size ordered collection of similar type. Any array can be used for storing a group of data. In other words, we can define an array like the group of variables of a similar type.
API Configuring
We can efficiently configure an API with the help of the following script:
Array Statistics Methods of API
A few essential array statistics methods of API are listed as under:
- d3.max(array)
- d3.min(array)
- d3.sum(array)
- d3.extent(array)
- d3.mean(array)
- d3.variance(array)
- d3.quantile(array)
- d3.deviation(array)
Let’s explain all the above methods.
d3.max(array)
The d3.max(array) returns any maximum value within the provided array.
Let’s consider an example.
Example:
Output:
d3.min(array)
The d3.min(array) returns any minimum value with the help of the natural order.
Let’s consider an example.
Example:
Output:
d3.sum(array)
It will return the provided array number’s sum. If an array will be empty, it will return 0.
Let’s consider an example.
Example:
Output:
d3.extent(array)
It will return both maximum and minimum values within the provided array.
Let’s consider an example.
Example:
Output:
d3.mean(array)
The d3.mean methods returns the provided array number’s mean.
Let’s consider an example.
Example:
Output:
d3.variance(array)
The d3.variance method returns the provided array’s variance.
d3.quantile(array)
It returns the provided sorted array number’s p-quantile, in which p is any number inside the [0, 1] range.
For example: A median could be solved with the use of p= 0.5, p=0.25 will be the first quantile, and p= 0.75 will be the third quantile.
This execution applies the R-7 technique, where Excel and R programming language are considered by default.
d3.deviation(array)
It returns the provided array’s standard deviation. When an array contains two values and it will be returned as undefined.
API Methods in Array Search
Following are the two essential methods of API search.
- d3.scan(array, comparator)
- d3.ascending(a, b)
d3.scan(array, comparator)
The d3.scan(array) method can be used to illustrate the specified array’s linear scan. It will return the current element’s index to any specified comparator.
Let’s consider an example.
Example:
The following code will be implemented using the d3.scan(array) function with the comparator.
Output:
d3.descending(a, b)
The above method, i.e., d3.descending(a, b) is applied to perform a comparator function. It could be executed as:
Here a, b are two values. When there is no specified function to any built-in sort technique, the default sequence is alphabetical. It will return -1 value if it takes two parameters in descending sequence (the first parameter has larger value than the second parameter).
We can illustrate descending(a, b) method similarly. It will return 1 value if it takes two parameters in ascending sequence (the first parameter has smaller value than the second parameter). It will return 0 when it holds two same parameters.
Let’s consider an example.
Example:
Output:
Array API Transformations
The following are a few most critical array API transformations methods.
- d3.cross(a, b[, reducer])
- d3.pairs(array[, reducer])
- d3.merge(array)
- d3.zip(arrays)
- d3.permute(array, indexes)
d3.cross(a, b[, reducer])
The d3.cross(a, b[, reducer]) method can be applied to return any two given array’s ( like a and b) Cartesian product.
A general illustration can be as follows:
Example:
Output:
d3.pairs(array[, reducer])
It is applicable to pair the elements of an array and can be illustrated as under:
Example:
Output:
d3.merge(array)
It is defined for array merging and can be described as under:
Example:
Output:
d3.zip(arrays)
The above method is applicable to return the array’s array. If the arrays consist of an individual array, then returned array will also include a single-element array. When no arguments are described, the returned array will be empty.
d3.permute(array, indexes)
It is applied to implement the permutation process from the specified indexes and array. We can also implement various values from the object into an array.
It can be defined as below:
Syntax: