---
title: "Nonlinear Least Squares"
method: POST
path: "/quantlib/numerical/least-squares/fit"
tags: ["quantlib-numerical"]
---

# Nonlinear Least Squares

`POST /quantlib/numerical/least-squares/fit`

## Request

- Base URL: `https://api.fincept.in` (the document declares no server; this is the origin it was published from)
- URL: `https://api.fincept.in/quantlib/numerical/least-squares/fit`
- Auth: API key in header `X-API-Key`

Nonlinear least squares fitting

## Request body

- NLLeastSquaresRequest: Nonlinear least squares — fit a model to data
  - `model` string, required
  - `x_data` number[], required
  - `y_data` number[], required
  - `x0` number[], required

## Response `200`

Successful Response

- unknown

## Other responses

- `422`: Validation Error

---

[API](https://skmtc.dev/fincept/apis/fincept-api.md) · [All operations](https://skmtc.dev/fincept/apis/fincept-api/llms.txt) · [OpenAPI document](https://skmtc.dev/fincept/apis/fincept-api/revisions/e9c0076ea55a?raw)