FORECAST function

PRO

The FORECAST function in Jspreadsheet Formulas Pro is a tool used to estimate or predict a future value based on existing data. It operates based on the principle of linear regression, which involves finding the best-fitting straight line through historical data points. By inputting known data points, the FORECAST function can calculate and suggest a likely future value. This is particularly useful for trends analysis and budgeting purposes.

Documentation

Calculates or predicts a future value by using linear regression.

Syntax

FORECAST(x, known_y_values, known_x_values)

Parameter	Description
`x`	The x-value used to predict the y-value.
`known_y_values`	An array of y-values representing known data points that you want to use in the regression analysis.
`known_x_values`	An array of x-values representing known data points that you want to use in the regression analysis. The number of elements in known_x's should be equal to the number of elements in known_y's.

Behavior

The FORECAST function is used to predict future values by using existing (historical) data. The function uses a linear regression algorithm based on the provided data series.

If a cell in either known_y_values or known_x_values range is empty or contains text, the function will ignore that cell and the corresponding data point in the other range.
If the known_y_values or known_x_values arrays are different sizes, the function will return an #N/A error.
If the known_x_values array contains duplicate values, FORECAST will return a #DIV/0! error.
The FORECAST function does not handle non-numeric data. If the known_y_values or known_x_values arrays contain non-numeric data (like text or booleans), the function will return a #VALUE! error.

Common Errors

Error	Description
#N/A	The 'known_y's' or 'known_x's' arrays are different sizes
#DIV/0!	The 'known_x's' array contains duplicate values
#VALUE!	The 'known_y's' or 'known_x's' arrays contain non-numeric data (like text or booleans)

Best practices

Ensure that your 'known_y's' and 'known_x's' arrays are of the same size to avoid '#N/A' errors.

Try to avoid having duplicate values in your 'known_x's' array to prevent '#DIV/0!' errors.

Make sure that your 'known_y's' and 'known_x's' arrays contain only numeric data. Non-numeric data will result in '#VALUE!' errors.

The 'FORECAST' function is best used for data sets that have a linear relationship. If your data shows an exponential or polynomial trend, consider using other forecasting methods.

Usage

A few examples using the FORECAST function.

FORECAST(10, B2:B8, A2:A8)   // Predict value when x = 10 using historical X and Y ranges
FORECAST(20, B2:B8, A2:A8)   // Predict value when x = 20
FORECAST(30, B2:B8, A2:A8)   // Predict value when x = 30

Interactive Spreadsheet Demo

<html>
<script src="https://jspreadsheet.com/v11/jspreadsheet.js"></script>
<script src="https://jsuites.net/v5/jsuites.js"></script>
<link rel="stylesheet" href="https://jsuites.net/v5/jsuites.css" type="text/css" />
<link rel="stylesheet" href="https://jspreadsheet.com/v11/jspreadsheet.css" type="text/css" />

<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Material+Icons" />
<script src="https://cdn.jsdelivr.net/npm/@jspreadsheet/formula-pro/dist/index.min.js"></script>

<div id="spreadsheet"></div>

<script>
// Set your JSS license key (The following key only works for one day)
jspreadsheet.setLicense('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');

// Set the extensions
jspreadsheet.setExtensions({ formula });

// Create a new spreadsheet
jspreadsheet(document.getElementById('spreadsheet'), {
  worksheets: [{
    data: [
    [
        "Month",
        "Sales",
        "Forecast for Month 7"
    ],
    [
        1,
        1200
    ],
    [
        2,
        1350
    ],
    [
        3,
        1480
    ],
    [
        4,
        1620
    ],
    [
        5,
        1750
    ],
    [
        6,
        1890
    ],
    [
        7,
        "=FORECAST(7,B2:B7,A2:A7)"
    ]
]
  }]
});
</script>
</html>

import React, { useRef } from "react";
import { Spreadsheet, Worksheet, jspreadsheet } from "@jspreadsheet/react";
import formula from "@jspreadsheet/formula-pro";
import "jsuites/dist/jsuites.css";
import "jspreadsheet/dist/jspreadsheet.css";

// Set license
jspreadsheet.setLicense('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');

// Set the extensions
jspreadsheet.setExtensions({ formula });

export default function App() {
    // Spreadsheet array of worksheets
    const spreadsheet = useRef();

    // Worksheet data
    const data = [
    [
        "Month",
        "Sales",
        "Forecast for Month 7"
    ],
    [
        1,
        1200
    ],
    [
        2,
        1350
    ],
    [
        3,
        1480
    ],
    [
        4,
        1620
    ],
    [
        5,
        1750
    ],
    [
        6,
        1890
    ],
    [
        7,
        "=FORECAST(7,B2:B7,A2:A7)"
    ]
];

    // Render component
    return (
        <Spreadsheet ref={spreadsheet}>
            <Worksheet data={data} />
        </Spreadsheet>
    );
}

<template>
    <Spreadsheet ref="spreadsheet">
        <Worksheet :data="data" />
    </Spreadsheet>
</template>

<script>
import { Spreadsheet, Worksheet, jspreadsheet } from "@jspreadsheet/vue";
import "jsuites/dist/jsuites.css";
import "jspreadsheet/dist/jspreadsheet.css";
import formula from "@jspreadsheet/formula-pro";

// Set license
jspreadsheet.setLicense('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');

// Set the extensions
jspreadsheet.setExtensions({ formula });

export default {
    components: {
        Spreadsheet,
        Worksheet,
    },
    data() {
        // Worksheet data
        const data = [
    [
        "Month",
        "Sales",
        "Forecast for Month 7"
    ],
    [
        1,
        1200
    ],
    [
        2,
        1350
    ],
    [
        3,
        1480
    ],
    [
        4,
        1620
    ],
    [
        5,
        1750
    ],
    [
        6,
        1890
    ],
    [
        7,
        "=FORECAST(7,B2:B7,A2:A7)"
    ]
]

        return {
            data
        };
    }
}
</script>

import { Component, ViewChild, ElementRef } from "@angular/core";
import jspreadsheet from "jspreadsheet";
import * as formula from "@jspreadsheet/formula-pro";

// Set your JSS license key (The following key only works for one day)
jspreadsheet.setLicense('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');

// Set the extensions
jspreadsheet.setExtensions({ formula });

@Component({
    standalone: true,
    selector: "app-root",
    template: `<div #spreadsheet></div>`
})
export class AppComponent {
    @ViewChild("spreadsheet") spreadsheet: ElementRef;
    // Worksheets
    worksheets: jspreadsheet.worksheetInstance[];

    // Create a new data grid
    ngAfterViewInit() {
        // Create spreadsheet
        this.worksheets = jspreadsheet(this.spreadsheet.nativeElement, {
            worksheets: [{
                data: [
    [
        "Month",
        "Sales",
        "Forecast for Month 7"
    ],
    [
        1,
        1200
    ],
    [
        2,
        1350
    ],
    [
        3,
        1480
    ],
    [
        4,
        1620
    ],
    [
        5,
        1750
    ],
    [
        6,
        1890
    ],
    [
        7,
        "=FORECAST(7,B2:B7,A2:A7)"
    ]
]
            }]
        });
    }
}

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