Series API

A Series represents a single column of typed data. It behaves like a smart array with built-in statistical capabilities.

Accessing Data

at

Get the value at a specific index.

at(index: number): any

length

The number of items in the Series.

console.log(series.length);

toArray

Convert the Series back to a standard JavaScript array.

const numbers = series.toArray(); // number[]

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Statistics

sum

Total sum of values (numeric only).

console.log(prices.sum());

mean

Average value (numeric only).

console.log(scores.mean());

min / max

Smallest and largest values.

console.log(dates.min()); // Earliest date

std

Standard deviation.

console.log(volatility.std());

valueCounts

Count occurrences of each unique value. Returns a new DataFrame.

const popularity = brands.valueCounts();
popularity.print();
// ┌───────┬───────┐
// │ value │ count │
// ├───────┼───────┤
// │ Apple │ 50    │
// │ Sony  │ 30    │
// └───────┴───────┘

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Transformation

map

Apply a function to every value. Returns a new Series.

const upper = names.map(name => name.toUpperCase());

sort

Sort the values.

const sorted = values.sort(false); // Descending

unique

Return a new Series with duplicate values removed.

const categories = allCategories.unique();

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Missing Values

isna

Returns a boolean Series indicating which values are null/undefined/NaN.

const missingMask = data.isna();

fillna

Replace missing values with a constant.

const clean = data.fillna(0);