Function reference · Calculus

`sum`

Evaluates a finite symbolic sum over an integer index.

With concrete integer bounds, Nerdamer substitutes the index through the inclusive range and adds the resulting symbolic terms. If a bound is still symbolic, the sum remains unevaluated.

Examples

These examples use Nerdamer Notation.

Sum the first five positive integers.

sum(k,k,1,5)
// → 15

Sum a polynomial expression over a finite range.

sum(k^2,k,1,4)
// → 30

Interfaces

The same operation is available through the interfaces below.

Nerdamer Notation · nerdamer API · Direct API

Nerdamer Notation

Use this form inside input passed to nerdamer(...).

sum(arg1, arg2, arg3, arg4)

`nerdamer.sum`

Call the operation through the default nerdamer import.

nerdamer.sum(expr: Expression, index: Expression, lower: Expression, upper: Expression): Expression

Parameters

Name	Type	Description
`expr`	`Expression`	The expression to be summed.
`index`	`Expression`	The index variable (must be a plain symbol).
`lower`	`Expression`	The lower bound (integer required for evaluation).
`upper`	`Expression`	The upper bound (integer required for evaluation).

Returns

Expression — The summation result or a symbolic `sum` node.

Browse the nerdamer API →

Direct JavaScript / TypeScript API

Import the operation directly from its package entry point.

import { sum } from 'nerdamer/calculus';

sum(expr: Expression, index: Expression, lower: Expression, upper: Expression): Expression

Parameters

Name	Type	Description
`expr`	`Expression`	The expression to be summed.
`index`	`Expression`	The index variable (must be a plain symbol).
`lower`	`Expression`	The lower bound (integer required for evaluation).
`upper`	`Expression`	The upper bound (integer required for evaluation).

Returns

Expression — The summation result or a symbolic `sum` node.

Browse nerdamer/calculus →

← Back to Reference