spreadsheetImportOptions - Import options object for Spreadsheets - MATLAB (original) (raw)

Import options object for Spreadsheets

Description

A SpreadsheetImportOptions object enables you to specify how MATLAB® imports tabular data from spreadsheet files. The object contains properties that control the data import process, including the handling of errors and missing data.

Creation

You can create a SpreadsheetImportOptions object by using either the detectImportOptions function or thespreadsheetImportOptions function (described here):

Use detectImportOptions to detect and populate the import properties based on the contents of the spreadsheet specified infilename.
opts = detectImportOptions(filename);
Use spreadsheetImportOptions to define the import properties based on your import requirements.

Syntax

Description

opts = spreadsheetImportOptions creates aSpreadsheetImportOptions object with one variable.

example

opts = spreadsheetImportOptions('NumVariables',[numVars](#bvetiw8-1%5Fsep%5Fmw%5Ff5acc160-778c-42ed-a7f2-be23ca93c208)) creates the object with the number of variables specified innumVars.

example

opts = spreadsheetImportOptions(___,`Name,Value`) specifies additional properties forSpreadsheetImportOptions object using one or more name-value pair arguments.

example

Input Arguments

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Number of variables, specified as a positive scalar integer.

Properties

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Variable Properties

Data Types: char | string | cell

Flag to preserve variable names, specified as either "modify" or"preserve".

"modify" — Convert invalid variable names (as determined by the isvarname function) to valid MATLAB identifiers.
"preserve" — Preserve variable names that are not valid MATLAB identifiers such as variable names that include spaces and non-ASCII characters.

Starting in R2019b, variable names and row names can include any characters, including spaces and non-ASCII characters. Also, they can start with any characters, not just letters. Variable and row names do not have to be valid MATLAB identifiers (as determined by the isvarname function). To preserve these variable names and row names, set the value of VariableNamingRule to "preserve". Variable names are not refreshed when the value of VariableNamingRule is changed from "modify" to "preserve".

Data Types: char | string

Location Properties

Data Types: char | string | single | double

Location of data to be imported, specified as a character vector, string scalar, cell array of character vectors, string array, positive scalar integer or an N-by-2 array of positive scalar integers. Specify DataRange using one of these forms.

Specified by	Behavior
'Cell' or _n_Starting Cell or Starting Row	Specify the starting cell for the data, using Excel® A1 notation. For example, A5 is the identifier for the cell at the intersection of column A and row 5.Using the starting cell, the importing function automatically detects the extent of the data, by beginning the import at the start cell and ending at the last empty row or footer range.Alternatively, specify the first row containing the data using the positive scalar row index. Using the specified row index, the importing function automatically detects the extent of the data by reading from the specified first row to the end of the data or the footer range.Example: 'A5' or 5
'Corner1:Corner2'Rectangular Range	Specify the exact range to read using the rectangular range form, where Corner1 and Corner2 are two opposing corners that define the region to read.The importing function only reads the data contained in the specified range. Any empty fields within the specified range are imported as missing cells.The number of columns must match the number specified in the NumVariables property.Example: 'A5:K50'
'Row1:Row2' or 'Column1:Column2'Row Range or Column Range	Specify the range by identifying the beginning and ending rows using Excel row numbers. Using the specified row range, the importing function automatically detects the column extent by reading from the first nonempty column to the end of the data, and creates one variable per column.Example: '5:500'Alternatively, specify the range by identifying the beginning and ending columns using Excel column letters or numbers.Using the specified column range, the import function automatically detects the row extent by reading from the first nonempty row to the end of the data or the footer range.The number of columns in the specified range must match the number specified in the NumVariables property.Example: 'A:K'
[n1 n2; n3 n4;...] Multiple Row Ranges	Specify multiple row ranges to read with an N-by-2 array containing N different row ranges.A valid array of multiple row ranges must: Specify line ranges in an increasing order, that is the first row range specified in the array appears in the file before the other row ranges.Contain only non-overlapping row ranges.Use of Inf is only supported to indicate the last range in the numeric array specifying multiple row ranges. For example, [1 3; 5 6; 8 Inf].Example: [1 3; 5 6; 8 Inf]
''Unspecified or Empty	Do not fetch any data.Example: ''

Data Types: char | string | cell | single | double

Location of row names, specified as a character vector, string scalar, positive scalar integer, or an empty character array. Specify RowNamesRange as one of the values in this table.

Specified by	Behavior
'Cell'	Specify the starting cell for the data, using Excel A1 notation. For example, A5 is the identifier for the cell at the intersection of column A and row 5.The importing function identifies a name for each variable in the data.Example: 'A5'
'Corner1:Corner2'Rectangular Range	Specify the exact range to read using the rectangular range form, where Corner1 and Corner2 are two opposing corners that define the region to read.The number of rows contained in RowNamesRange must match the number of data rows, and the range indicated by RowNamesRange must span only one column.Example: 'A5:A50'
'Row1:Row2'Row Range	Specify range by identifying the beginning and ending rows using Excel row numbers.Row names must be in a single column.Example: '5:50'
_n_Number Index	Specify the column containing the row names using a positive scalar column index. Example: 5
''Unspecified or Empty	Indicate that there are no row names.Example: ''

Data Types: char | single | double

Location of variable names, specified as a character vector, string scalar, positive scalar integer, or an empty character array. Specify VariableNamesRange as one of the values in this table.

Specified by	Behavior
'Cell'	Specify the starting cell for the data, using Excel A1 notation. For example, A5 is the identifier for the cell at the intersection of column A and row 5.The importing function reads a name for each variable in the data.Example: 'A5'
'Corner1:Corner2'Rectangular Range	Specify the exact range to read using the rectangular range form, where Corner1 and Corner2 are two opposing corners that define the region to read.The number of columns must match the number specified in the NumVariables property, and the range must span only one row.Example: 'A5:K5'
'Row1:Row2'Row Range	Specify range by identifying the beginning and ending rows using Excel row numbers. Must be a single row.Example: '5:5'
_n_Number Index	Specify the row containing the variable names using a positive scalar row index. Example: 5
''Unspecified or Empty	Indicate that there are no variable names.Example: ''

Data Types: char | single | double

Location of variable descriptions, specified as a character vector, string scalar, positive scalar integer, or an empty character array. Specify VariableDescriptionRange as one of the values in this table.

Specified by	Behavior
'Cell'	Specify the starting cell for the data, using Excel A1 notation. For example, A5 is the identifier for the cell at the intersection of column A and row 5.The importing function reads a description for each variable in the data.Example: 'A5'
'Corner1:Corner2'Rectangular Range	Specify the exact range to read using the rectangular range form, where Corner1 and Corner2 are two opposing corners that define the region to read.The number of columns must match the number specified in the NumVariables property, and the range must span only one row.Example: 'A5:K5'
'Row1:Row2'Row Range	Specify range by identifying the beginning and ending rows using Excel row numbers. Must be a single row.Example: '5:5'
_n_Number Index	Specify the row containing the descriptions using a positive scalar row index. Example: 5
''Unspecified or Empty	Indicate that there are no variable descriptions.Example: ''

Data Types: char | string | single | double

Location of variable units, specified as a character vector, string scalar, positive scalar integer, or an empty character array. Specify VariableUnitsRange as one of the values in this table.

Specified by	Behavior
'Cell'	Specify the starting cell for the data, using Excel A1 notation. For example, A5 is the identifier for the cell at the intersection of column A and row 5.The importing function reads a unit for each variable in the data.Example: 'A5'
'Corner1:Corner2'Rectangular Range	Specify the exact range to read using the rectangular range form, where Corner1 and Corner2 are two opposing corners that define the region to read.The number of columns must match the number specified in the NumVariables property, and the range must span only one row.Example: 'A5:K5'
'Row1:Row2'Row Range	Specify range by identifying the beginning and ending rows using Excel row numbers. Must be a single row.Example: '5:5'
_n_Number Index	Specify the row containing the data units using a positive scalar row index. Example: 5
''Unspecified or Empty	Indicate that there are no variable units.Example: ''

Data Types: char | string | single | double

Replacement Rules

Data Types: char | string

Object Functions

Examples

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Create an import options object to read one variable from the file patients.xls.

Initialize a SpreadsheetImportOptions object, specify the variable name, variable type, and the data starting cell. Then, use the preview function with the import options object to preview the data.

opts = spreadsheetImportOptions; opts.VariableNames = 'LastName'; opts.VariableTypes = 'categorical'; opts.DataRange = 'A2'; preview('patients.xls',opts)

ans=8×1 table LastName ________

Smith   
Johnson 
Williams
Jones   
Brown   
Davis   
Miller  
Wilson

Import the variable from the file.

oneVar = readtable('patients.xls',opts); whos oneVar

Name Size Bytes Class Attributes

oneVar 100x1 14309 table

Create an import options object to read multiple variables from patients.xls.

Based on the contents of your file, define the number of variables, variable names, variable types, and the data starting location.

numVars = 7; varNames = {'LastName','Gender','Age','Location','Height','Weight','Smoker'} ; varTypes = {'char','categorical','int32','char','double','double','logical'} ; dataStartLoc = 'A2';

Initialize the import options object opts using the spreadsheetImportOptions function and your variable information.

opts = spreadsheetImportOptions('NumVariables',numVars,... 'VariableNames',varNames,... 'VariableTypes',varTypes,... 'DataRange', dataStartLoc);

Preview the data using the preview function with the import options.

preview('patients.xls',opts)

ans=8×7 table LastName Gender Age Location Height Weight Smoker ____________ ______ ___ _____________________________ ______ ______ ______

{'Smith'   }    Male      38     {'County General Hospital'  }      71       176      true  
{'Johnson' }    Male      43     {'VA Hospital'              }      69       163      false 
{'Williams'}    Female    38     {'St. Mary's Medical Center'}      64       131      false 
{'Jones'   }    Female    40     {'VA Hospital'              }      67       133      false 
{'Brown'   }    Female    49     {'County General Hospital'  }      64       119      false 
{'Davis'   }    Female    46     {'St. Mary's Medical Center'}      68       142      false 
{'Miller'  }    Female    33     {'VA Hospital'              }      64       142      true  
{'Wilson'  }    Male      40     {'VA Hospital'              }      68       180      false

Import the data using readtable.

T = readtable('patients.xls',opts); whos T

Name Size Bytes Class Attributes

T 100x7 33987 table

Version History

Introduced in R2016b

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Use the spreadsheetImportOptions function to create aSpreadsheetImportOptions object. Previously, you could create this object only by using the detectImportOptions function.