# What is an ARRAY formula in a spreadsheet?

Array formulas allow you to perform calculations on multiple values simultaneously within a range. They can process arrays of data and return arrays of results, making it easier to perform complex calculations or operations across multiple cells.

## ARRAY formula usage examples.

The ARRAY_CONSTRAIN function is used to constrain an array result to a specified size. It takes three arguments: the input range, the number of rows to include, and the number of columns to include. The function returns a new array that contains only the specified number of rows and columns from the input range.

The CHOOSECOLS function creates a new array by selecting specific columns from an existing range. It takes an array as the input and allows you to specify the column numbers you want to include in the new array. The resulting array will only contain the selected columns, preserving the original row order.

The CHOOSEROWS function creates a new array from the selected rows in the existing range. It allows you to filter data based on specific criteria and retrieve the rows that meet the criteria. The function takes a data range as the first argument, followed by one or more criteria to filter the rows. The resulting array can be used in various calculations and data manipulations.

The GROWTH function in Excel is used to fit an ideal exponential growth trend and/or predict further values based on known data points. It calculates the growth rate and uses it to estimate future values. The function takes the known y-values (dependent variable) and optional x-values (independent variable) as input, along with optional new x-values for which the function predicts the corresponding y-values. The optional b argument allows for additional constraints on the growth rate.

The HSTACK function is used to append ranges or lists horizontally and create a larger array or merged list. It takes multiple arguments, which can be ranges or lists, and combines them horizontally. The resulting array or list will have the same number of rows as the input ranges or lists, and the columns will be appended in sequence.

The LINEST function is used to calculate various parameters of a linear trend using the least-squares method. It returns an array of values that represent the coefficients of the linear equation that best fits the given data points. The function takes the following arguments: - known_data_y: The array or range of dependent data points. - known_data_x (optional): The array or range of independent data points. If omitted, the function assumes a simple linear regression with the independent variable being the array [1, 2, 3, ...]. - calculate_b (optional): A logical value that determines whether to calculate the y-intercept (b) of the linear equation. If set to TRUE or omitted, the function calculates the y-intercept. If set to FALSE, the function assumes a y-intercept of 0. - verbose (optional): A logical value that determines whether to return additional statistical information. If set to TRUE, the function returns additional information such as the standard error and degrees of freedom. If set to FALSE or omitted, only the coefficients of the linear equation are returned.

The LOGEST function calculates the parameters of the best-fit exponential growth curve based on known data points. It returns an array of values that represent the coefficients of the curve equation. The function can handle both single-variable and multiple-variable data. The optional arguments allow for additional customization and verbose output.

The MAKEARRAY function returns an array of specified dimensions with values calculated by the application of a LAMBDA function. It takes three arguments: 'rows' (the number of rows in the array), 'columns' (the number of columns in the array), and 'LAMBDA' (a function that defines how each value in the array is calculated).

The TOCOL function transforms an array or range of cells into a single column. It takes an array or range as input and returns a single column with all the values from the input. The optional 'ignore' parameter allows you to specify values to ignore during the transformation. The optional 'scan_by_column' parameter determines whether the input should be scanned by column or by row. By default, the function scans by row.

The TREND function is used to calculate and predict values based on a linear trend using the least squares method. It takes known y-values, optional known x-values, optional new x-values, and an optional constant 'b' as input. The function returns an array of predicted y-values corresponding to the new x-values.

The VSTACK function is used to append ranges vertically and in sequence to return a larger array. It takes multiple ranges as arguments and stacks them vertically, combining them into a single column or array. This function is particularly useful when you need to consolidate data from multiple sources or when you want to combine data from different worksheets or workbooks.

The WRAPROWS function wraps the provided row or column of cells by rows after a specified number of elements to form a new array. It takes three parameters: range, wrap_count, and pad_with (optional). The range parameter specifies the range of cells to wrap. The wrap_count parameter determines the number of elements in each row of the new array. The pad_with parameter is optional and specifies the value to use for padding if the original range does not have enough elements to fill the last row.