tabularTextDatastore
Datastore for tabular text files
Description
Use a TabularTextDatastore
object to manage large
collections of text files containing column-oriented or tabular data where the
collection does not necessarily fit in memory. Tabular data is data that is arranged in
a rectangular fashion with each row having the same number of entries. You can create a
TabularTextDatastore
object using the
tabularTextDatastore
function, specify its properties, and then
import and process the data using object functions.
Creation
Description
creates a datastore from the collection of data specified by
ttds
= tabularTextDatastore(location
)location
.
specifies additional parameters and properties for ttds
= tabularTextDatastore(location
,Name,Value
)ttds
using one or more name-value
pair arguments. For example,
tabularTextDatastore(location,"FileExtensions",[".txt",".csv"])
creates a datastore from only the files in location
with
extensions .txt
and .csv
.
Input Arguments
location
— Files or folders included in datastore
FileSet
| DsFileSet
object | string array | character vector | cell array of character vectors
Files or folders to include in the datastore, specified as one of these values:
FileSet
object — Specifying the location as aFileSet
object leads to a faster construction time for datastores compared to specifying a path orDsFileSet
object. For more information, seematlab.io.datastore.FileSet
.DsFileSet
object — For more information, seematlab.io.datastore.DsFileSet
.File path — You can specify a single file path as a string scalar or character vector. You can specify multiple file paths as a string array or cell array of character vectors.
Files or folders can be local or remote:
Local files or folders — If the files are not in the current folder, then specify full or relative paths. Files within subfolders of a specified folder are not automatically included in the datastore. You can use the wildcard character (*) when specifying the local path. This character specifies that the datastore include all matching files or all files in the matching folders.
Remote files or folders — Specify full paths to remote files or folders as a uniform resource locator (URL) of the form
hdfs:///
. Internet URLs must include the protocol typepath_to_file
"http://"
or"https://"
. For more information, see Work with Remote Data.
When you specify a folder, the datastore includes only files with supported file
formats and ignores files with any other format. To specify a custom list of file extensions to
include in your datastore, see the FileExtensions
name-value argument.
The tabularTextDatastore
function supports files
with .txt
, .csv
,
.dat
, .dlm
,
.asc
, and .text
extensions as
well as files with no extension.
Example: "file1.csv"
Example: "../dir/data/file1"
Example: ["C:\dir\data\file1.csv","C:\dir\data\file2.dat"]
Example: "C:\dir\data\*.text"
Specify optional pairs of arguments as
Name1=Value1,...,NameN=ValueN
, where Name
is
the argument name and Value
is the corresponding value.
Name-value arguments must appear after other arguments, but the order of the
pairs does not matter.
Example: ttds =
tabularTextDatastore("C:\dir\textdata",FileExtensions=[".csv",".txt"])
Before R2021a, use commas to separate each name and value, and enclose
Name
in quotes.
Example: ttds =
tabularTextDatastore("C:\dir\textdata","FileExtensions",[".csv",".txt"])
FileExtensions
— Text file extensions
character vector | cell array of character vectors | string scalar | string array
Text file extensions, specified as the comma-separated pair
consisting of "FileExtensions"
and a character
vector, cell array of character vectors, string scalar, or string
array. The specified extensions do not require a supported format.
If you want to include unsupported extensions, then specify all
extensions. Use empty quotes ""
to represent
files without extensions.
Example: "FileExtensions",".txt"
Example: "FileExtensions",[".text",".csv"]
Data Types: char
| cell
| string
IncludeSubfolders
— Subfolder inclusion flag
true
or false
| 0 or 1
Subfolder inclusion flag, specified as the name-value argument
consisting of "IncludeSubfolders"
and
true
, false
, 0, or 1.
Specify true
to include all files and subfolders
within each folder or false
to include only the
files within each folder.
When you do not specify "IncludeSubfolders"
,
then the default value is false
.
Example: "IncludeSubfolders",true
Data Types: logical
| double
OutputType
— Output datatype
"auto"
(default) | "table"
| "timetable"
Output datatype, specified as the name-value argument consisting of
"OutputType"
and one of these values:
The value of OutputType
determines the data type returned by the preview
, read
, and readall
functions. Use this option in conjunction with the
"RowTimes"
name-value pair to return timetables from
TabularTextDatastore
.
Example: "OutputType","timetable"
Data Types: char
| string
AlternateFileSystemRoots
— Alternate file system root paths
string vector | cell array
Alternate file system root paths, specified as the name-value argument consisting of
"AlternateFileSystemRoots"
and a string vector or a cell array. Use
"AlternateFileSystemRoots"
when you create a datastore on a local
machine, but need to access and process the data on another machine (possibly of a different
operating system). Also, when processing data using the Parallel Computing Toolbox™ and the MATLAB®
Parallel Server™, and the data is stored on your local machines with a copy of the data available
on different platform cloud or cluster machines, you must use
"AlternateFileSystemRoots"
to associate the root paths.
To associate a set of root paths that are equivalent to one another, specify
"AlternateFileSystemRoots"
as a string vector. For example,["Z:\datasets","/mynetwork/datasets"]
To associate multiple sets of root paths that are equivalent for the datastore, specify
"AlternateFileSystemRoots"
as a cell array containing multiple rows where each row represents a set of equivalent root paths. Specify each row in the cell array as either a string vector or a cell array of character vectors. For example:Specify
"AlternateFileSystemRoots"
as a cell array of string vectors.{["Z:\datasets", "/mynetwork/datasets"];... ["Y:\datasets", "/mynetwork2/datasets","S:\datasets"]}
Alternatively, specify
"AlternateFileSystemRoots"
as a cell array of cell array of character vectors.{{'Z:\datasets','/mynetwork/datasets'};... {'Y:\datasets', '/mynetwork2/datasets','S:\datasets'}}
The value of "AlternateFileSystemRoots"
must satisfy these conditions:
Contains one or more rows, where each row specifies a set of equivalent root paths.
Each row specifies multiple root paths and each root path must contain at least two characters.
Root paths are unique and are not subfolders of one another.
Contains at least one root path entry that points to the location of the files.
For more information, see Set Up Datastore for Processing on Different Machines or Clusters.
Example: ["Z:\datasets","/mynetwork/datasets"]
Data Types: string
| cell
TextType
— Output data type of text variables
"char"
(default) | "string"
Output data type of text variables, specified as the
comma-separated pair consisting of "TextType"
and
either "char"
or "string"
. If
the output table from the read
,
readall
, or preview
functions contains text variables, then
"TextType"
specifies the data type of those
variables for TabularTextDatastore
. If
"TextType"
is "char"
, then
the output is a cell array of character vectors. If
"TextType"
is "string"
,
then the output has type string
.
Data Types: char
| string
DatetimeType
— Type for imported date and time data
"datetime"
(default) | "text"
Type for imported date and time data, specified as the
comma-separated pair consisting of "DatetimeType"
and one of these values: "datetime"
or
"text"
.
Value | Type for Imported Date and Time Data |
---|---|
"datetime" | MATLAB
For more information, see |
"text" | If
|
If the specified TextscanFormats
property contains a %D
, then the
tabularTextdatastore
ignores the value
specified in DatetimeType
.
Example: "DatetimeType","datetime"
Data Types: char
| string
DurationType
— Output data type of duration data
"duration"
(default) | "text"
Output data type of duration data, specified as the name-value
argument consisting of "DurationType"
and either
"duration"
or "text"
.
Value | Type for Imported Duration Data |
---|---|
"duration" | MATLAB
For more information, see |
"text" | If
|
Data Types: char
| string
DatetimeLocale
— Locale to interpret dates
"en_US"
(default) | character vector | string scalar
Locale to interpret dates, specified as a character vector or
string scalar. The DatetimeLocale
value
determines how the importing function interprets text that
represents dates and times.
When specifying the DatetimeLocale
, use the
form
,
where xx
_YY
xx
is a lowercase ISO 639-1
two-letter code that specifies a language, and
YY
is an uppercase ISO 3166-1 alpha-2
code that specifies a country.
This table lists some common values for the locale.
Locale | Language | Country |
---|---|---|
"de_DE" | German | Germany |
"en_GB" | English | United Kingdom |
"en_US" | English | United States |
"es_ES" | Spanish | Spain |
"fr_FR" | French | France |
"it_IT" | Italian | Italy |
"ja_JP" | Japanese | Japan |
"ko_KR" | Korean | Korea |
"nl_NL" | Dutch | Netherlands |
"zh_CN" | Chinese (simplified) | China |
Note
The Locale
value determines how input
values are interpreted. The display format and language is
specified by the Locale option
in the Datetime format section
of the Preferences window. To change the default datetime
locale, see Set Command Window Preferences.
Data Types: char
| string
In addition to these name-value pairs, you also can specify the properties on
this page as name-value pairs, with the exception of the
Files
property.
Properties
TabularTextDatastore
properties describe the files
associated with a TabularTextDatastore
object. Specifically, the
properties describe the format of the data in the files and control how the data should
be read from the datastore. When you create a TabularTextDatastore
object, the datastore function uses the first file in the Files
property to determine the values of the properties. With the exception of the
Files
property, you can specify the value of
TabularTextDatastore
properties using name-value pair arguments
when you create the datastore object. To view or modify a property after creating the
object, use the dot notation:
ds = tabularTextDatastore("airlinesmall.csv"); ds.TreatAsMissing = "NA"; ds.MissingValue = 0;
File Properties
Files
— Files included in datastore
cell array of character vectors | string array
Files included in the datastore, resolved as a cell array of character
vectors or a string array, where each character vector or string is a
full path to a file. The location
argument in the
tabularTextDatastore
and
datastore
functions define these files.
The first file specified by the Files
property
determines the variable names and format information for all files in
the datastore.
When you change the value of this property, the datastore function
reevaluates the values of the TabularTextDatastore
properties.
Example: {"C:\dir\data\mydata1.csv";"C:\dir\data\mydata2.csv"}
Data Types: cell
| string
FileEncoding
— File encoding
"UTF-8"
(default) | "US-ASCII"
| "Macintosh"
| ...
File encoding, specified as a character vector or a string scalar like one of these values.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
| |
|
| |
|
| |
| ||
|
If each file in the datastore fits into memory, then
FileEncoding
also can be one of these
values.
|
|
|
|
|
|
|
|
|
|
|
When you change the value of this property, the datastore function
reevaluates the values of the TabularTextDatastore
properties.
Data Types: char
| string
ReadVariableNames
— Read variable names
true
| false
Read variable names, specified as a logical true
or
false
.
If unspecified, the
tabularTextDatastore
function detects the presence of variable names automatically.If
true
, then the first nonheader row of the first file determines the variable names for the data.If
false
, then the first nonheader row of the first file contains the first row of data. The data is assigned default variable names,Var1
,Var2
, and so on.
When you change the value of this property, the datastore function
reevaluates the values of the TabularTextDatastore
properties.
Data Types: logical
VariableNamingRule
— Flag to preserve variable names
"modify"
(default) | "preserve"
Flag to preserve variable names, specified as either "modify"
or
"preserve"
.
"modify"
— Convert invalid variable names (as determined by theisvarname
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
VariableNames
— Names of variables
cell array of character vectors | string array
Names of variables in the datastore, specified as a cell array of
character vectors or a string array. Specify the variable names in the
order in which they appear in the files. If you do not specify the
variable names, they are detected from the first nonheader line in the
first file of the datastore. When modifying the
VariableNames
property, the number of new
variable names must match the number of original variable names.
To support invalid MATLAB identifiers as variable names, such as variable names
containing spaces and non-ASCII characters, set the value of the
VariableNamingRule
parameter to
"preserve"
.
If ReadVariableNames
is false
,
then VariableNames
defaults to
{"Var1","Var2", ...}
.
Example: {"Time","Name","Quantity"}
Data Types: cell
| string
Text Format Properties
NumHeaderLines
— Number of lines to skip
non-negative integer
Number of lines to skip at the beginning of the file, specified as a
nonnegative integer. If unspecified, the
tabularTextDatastore
function detects the number
of lines to skip automatically.
The tabularTextDatastore
function ignores the
specified number of header lines before reading the variable names or
data.
When you change the value of this property, the datastore function
reevaluates the values of the TabularTextDatastore
properties.
Data Types: double
Delimiter
— Field delimiter characters
character vector | cell array of character vectors | string scalar | string array
Field delimiter characters, specified as a character vector, cell
array of character vectors, string scalar, or string array. Specify
multiple delimiters in a cell array of character vectors or a string
array. If unspecified, the tabularTextDatastore
function detects the delimiter automatically.
Example: "|"
Example: {";","*"}
Repeated delimiter characters in a file are interpreted as separate delimiters with empty fields between them. If unspecified, the read function detects the delimiter automatically by default.
When you specify one of the following escape sequences as a delimiter, it is converted to the corresponding control character.
\b | Backspace |
\n | Newline |
\r | Carriage return |
\t | Tab |
\\ | Backslash (\ ) |
When you change the value of this property, the datastore function
reevaluates the values of the TabularTextDatastore
properties.
Data Types: char
| cell
| string
RowDelimiter
— Row delimiter character
\r\n
(default) | character vector | string scalar
Row delimiter character, specified as a character vector or string
scalar that must be either a single character or one of
"\r"
, "\n"
, or
"\r\n"
.
When you change the value of this property, the datastore function
reevaluates the values of the TabularTextDatastore
properties.
Example: ":"
Data Types: char
| string
TreatAsMissing
— Text to treat as missing values
""
(default) | character vector | cell array of character vectors | string scalar | string array
Text to treat as missing values, specified as a single character
vector, cell array of character vectors, string scalar, or string array.
Values specified as TreatAsMissing
are substituted
with the value defined in the MissingValue
property.
For instance, if MissingValue
is defined to be a
NaN
, and the TreatAsMissing
is
specified as "NA"
. Then, in the imported data, all
occurrences of "NA"
are replaced by
NaN
.
This option only applies to numeric fields. Also, this property is
equivalent to the TreatAsEmpty
name-value pair
argument for the textscan
function.
When you change the value of this property, the datastore function
reevaluates the values of the TabularTextDatastore
properties.
Example: "NA"
Example: {"-",""}
Data Types: char
| cell
| string
MissingValue
— Value for missing numeric fields
NaN
(default) | scalar
Value for missing numeric fields in delimited text files, specified as
a scalar. This property is equivalent to the
EmptyValue
name-value pair argument for the
textscan
function.
Data Types: double
Advanced Text Format Properties
TextscanFormats
— Data field format
cell array of character vectors | string array
Data field format, specified as a cell array of character vectors or a string array, where each character vector or string contains one conversion specifier.
When you specify or modify the TextscanFormats
property, you can use the same conversion specifiers that the textscan
function
accepts for the formatSpec
argument. Valid values for
TextscanFormats
include conversion specifiers
that skip fields using an asterisk (*) character and ones that skip
literal text. The number of conversion specifiers must match the number
of variables in the VariableNames
property.
If the value of
TextscanFormats
includes conversion specifiers that skip fields using asterisk characters (*), then the value of theSelectedVariableNames
property automatically updates. MATLAB uses the%*q
conversion specifier to skip fields omitted by theSelectedVariableNames
property and treats the field contents as literal character vectors. For fixed-width files, indicate a skipped field using the appropriate conversion specifier along with the field width. For example,%*52c
skips a field that contains 52 characters.If you do not specify a value for
TextscanFormats
, thendatastore
determines the format of the data fields by scanning text from the first nonheader line in the first file of the datastore.Starting in R2020b,
datastore
detects prefixed literals as hexadecimal and binary data. Previously,datastore
detected prefixed literals as text data.
Example: {"%s","%s","%f"}
Data Types: cell
| string
ExponentCharacters
— Exponent characters
"eEdD"
(default) | character vector | string scalar
Exponent characters, specified as a character vector or string scalar.
The default exponent characters are e
,
E
, d
, and
D
.
Data Types: char
| string
CommentStyle
— Comment character
""
(default) | character vector | string scalar | two-element array
Comment character used to distinguish comments in the file, specified as character vector, string scalar, or two-element string or cell array.
If you specify a character vector or string scalar, then all following text on the same line are interpreted as a comment. For example,
"CommentStyle","/*"
interprets all text after/*
on the same line as a comment.If you specify a two-element string vector or a two-element cell array containing character vectors, then all text between the two characters are interpreted as a comment. For example,
"CommentStyle",{"/*", "*/"}
interprets all text between"/*"
and"*/"
as a comment.
When reading from a TabularTextDatastore
, the
read
function checks for comments only at the
start of each field, not within a field.
When you change the value of this property, the
datastore
function reevaluates the values of the
TabularTextDatastore
properties.
Example: "CommentStyle",{"/*", "*/"}
Data Types: char
| cell
| string
Whitespace
— White-space characters
" \b\t"
(default) | character vector | string scalar
White-space characters, specified as a character vector or a string scalar of one or more characters.
When you specify one of the following escape sequences as any
white-space character, the datastore
function
converts that sequence to the corresponding control character.
\b | Backspace |
\n | Newline |
\r | Carriage return |
\t | Tab |
\\ | Backslash (\ ) |
When you change the value of this property, the datastore function
reevaluates the values of the TabularTextDatastore
properties.
Example: " \b\t"
Data Types: char
| string
MultipleDelimitersAsOne
— Multiple delimiter handling
0 (false)
(default) | 1 (true)
Multiple delimiter handling, specified as either
true
or false
. If
true
, then datastore
treats
consecutive delimiters as a single delimiter. Repeated delimiters
separated by white-space are also treated as a single delimiter.
When you change the value of this property, the datastore function
reevaluates the values of the TabularTextDatastore
properties.
Properties for preview
, read
, readall
Table
SelectedVariableNames
— Variables to read
cell array of character vectors | string array
Variables to read from the file, specified as a cell array of character vectors or a string array, where each character vector or string contains the name of one variable. You can specify the variable names in any order.
To support invalid MATLAB identifiers as variable names, such as variable names
containing spaces and non-ASCII characters, set the value of the
VariableNamingRule
parameter to
"preserve"
.
Example: ["Var3","Var7","Var4"]
Data Types: cell
| string
SelectedFormats
— Formats of selected variables
cell array of character vectors | string array
Formats of the selected variables to read, specified as a cell array
of character vectors or a string array, where each character vector or
string contains one conversion specifier. The variables to read are
indicated by the SelectedVariableNames
property. The
number of character vectors or strings in
SelectedFormats
must match the number of
variables to read.
You can use the same conversion specifiers that the
textscan
function accepts, including specifiers
that skip literal text. However, you cannot use a conversion specifier
that skips a field. That is, the conversion specifier cannot include an
asterisk character (*).
Example: ["%d","%d"]
Data Types: cell
| string
ReadSize
— Amount of data to read
20000 (default) | positive scalar | "file"
Amount of data to read in a call to the read
function, specified as a
positive scalar or "file"
.
If
ReadSize
is a positive integer, then each call toread
reads at mostReadSize
rows.If
ReadSize
is"file"
, then each call toread
reads all of the data in one file.
When you change ReadSize
from a numeric scalar to "file"
or vice versa, MATLAB resets the datastore to the state where no data has been read from
it.
Data Types: double
| char
| string
TextType
— Output data type of text variables
"char"
(default) | "string"
Output data type of text variables, specified as
"char"
or "string"
.
TextType
specifies the data type of text
variables formatted with %s
, %q
,
or [...]
.
If
TextType
is"char"
, then the output is a cell array of character vectors.If
TextType
is"string"
, then the output has typestring
.
Data Types: char
| string
RowTimes
— Name of row times variable
variable name | variable index
Name of row times variable, specified as the name-value argument consisting of
"RowTimes"
and a variable name (such as
"Date"
) or a variable index (such as 3
).
RowTimes
is a timetable-related parameter. Each row of a timetable is
associated with a time, which is captured in a time vector for the timetable. The
variable specified in RowTimes
must contain a
datetime
or a duration
vector.
If the value of "OutputType"
is "timetable"
, but you do
not specify "RowTimes"
, then TabularTextDatastore
uses the
first datetime
or duration
variable as the row
times for the timetable.
Properties for use by writeall
Folders
— Folders used to construct datastore
cell array of character vectors
This property is read-only.
Folders used to construct datastore, returned as a cell array of
character vectors. The cell array is oriented as a column vector. Each
character vector is a path to a folder that contains data files. The
location
argument in the
tabularTextDatastore
and
datastore
functions defines
Folders
when the datastore is created.
The Folders
property is reset when you modify the
Files
property of a
TabularTextDatastore
object.
Data Types: cell
SupportedOutputFormats
— Formats supported for writing
string row vector
This property is read-only.
Formats supported for writing, returned as a row vector of strings. This property
specifies the possible output formats when using writeall
to write output files from the datastore.
DefaultOutputFormat
— Default output format
string scalar
This property is read-only.
Default output format, returned as a string scalar. This property specifies the default format
when using writeall
to write output files from the datastore.
Data Types: string
Object Functions
hasdata | Determine if data is available to read |
numpartitions | Number of datastore partitions |
partition | Partition a datastore |
preview | Preview subset of data in datastore |
read | Read data in datastore |
readall | Read all data in datastore |
writeall | Write datastore to files |
reset | Reset datastore to initial state |
transform | Transform datastore |
combine | Combine data from multiple datastores |
isPartitionable | Determine whether datastore is partitionable |
isSubsettable | Determine whether datastore is subsettable |
isShuffleable | Determine whether datastore is shuffleable |
Examples
Select Variables to Read
Using either a FileSet object or a file path, create a datastore from the sample file airlinesmall_subset.csv
. Specify how to treat missing values. Select only variables of interest.
Create a FileSet object from the file airlinesmall_subset.csv
. Create a datastore where values of "NA"
are treated as missing and missing values are treated as 0
.
fs = matlab.io.datastore.FileSet("airlinesmall_subset.csv"); ds = tabularTextDatastore(fs,"TreatAsMissing","NA",... "MissingValue",0);
View the variables in the datastore.
ds.VariableNames
ans = 1x19 cell
{'Year'} {'Month'} {'DayofMonth'} {'DayOfWeek'} {'DepTime'} {'CRSDepTime'} {'ArrTime'} {'CRSArrTime'} {'UniqueCarrier'} {'FlightNum'} {'TailNum'} {'ActualElapsedTime'} {'CRSElapsedTime'} {'AirTime'} {'ArrDelay'} {'DepDelay'} {'Origin'} {'Dest'} {'Distance'}
Modify the SelectedVariableNames
property to specify the variables of interest.
ds.SelectedVariableNames = ["Year","Month","TailNum"];
Alternatively, you can specify the location of your data as a file path.
ds = tabularTextDatastore("airlinesmall_subset.csv");
Using either location format, you can also specify your variables of interest when you create the datastore.
ds = tabularTextDatastore("airlinesmall_subset.csv","TreatAsMissing","NA",... "MissingValue",0,"SelectedVariableNames",["Year","Month","TailNum"]);
Specify Format of Data to Read
Create a datastore from the sample file airlinesmall_subset.csv
, which contains tabular data.
ds = tabularTextDatastore("airlinesmall_subset.csv","TreatAsMissing","NA",... "MissingValue",0);
Specify the variables of interest.
ds.SelectedVariableNames = ["Year","Month","UniqueCarrier"];
View the SelectedFormats
property.
ds.SelectedFormats
ans = 1x3 cell
{'%f'} {'%f'} {'%q'}
The SelectedFormats
property specifies how the tabularTextDatastore
function interprets the format of the variables. The Year
and Month
variables are read as columns of floating-point values and the UniqueCarrier
variable as a column of text.
Modify the SelectedFormats
property to read the first two variables as signed integers and the third variable as a categorical value.
ds.SelectedFormats = ["%d","%d","%C"];
Preview the data.
T = preview(ds)
T=8×3 table
Year Month UniqueCarrier
____ _____ _____________
1996 1 HP
1996 1 HP
1996 1 HP
1996 1 HP
1996 1 US
1996 1 US
1996 1 US
1996 1 NW
Return Timetable from Tabular Text Datastore
Use the OutputType
and RowTimes
name-value pairs to make tabulartextDatastore
return timetables instead of tables.
Create a datastore for outages.csv
. Specify the "OutputType
" name-value pair as "timetable
".
ttds = tabularTextDatastore("outages.csv","OutputType","timetable"); preview(ttds)
ans=8×5 timetable
OutageTime Region Loss Customers RestorationTime Cause
________________ _____________ ______ __________ ________________ ___________________
2002-02-01 12:18 {'SouthWest'} 458.98 1.8202e+06 2002-02-07 16:50 {'winter storm' }
2003-01-23 00:49 {'SouthEast'} 530.14 2.1204e+05 NaT {'winter storm' }
2003-02-07 21:15 {'SouthEast'} 289.4 1.4294e+05 2003-02-17 08:14 {'winter storm' }
2004-04-06 05:44 {'West' } 434.81 3.4037e+05 2004-04-06 06:10 {'equipment fault'}
2002-03-16 06:18 {'MidWest' } 186.44 2.1275e+05 2002-03-18 23:23 {'severe storm' }
2003-06-18 02:49 {'West' } 0 0 2003-06-18 10:54 {'attack' }
2004-06-20 14:39 {'West' } 231.29 NaN 2004-06-20 19:16 {'equipment fault'}
2002-06-06 19:28 {'West' } 311.86 NaN 2002-06-07 00:51 {'equipment fault'}
When you do not also specify 'RowTimes'
, tabularTextDatastore
uses the first datetime or duration variable as the row times. In this case, the OutageTime
variable is used for the row times.
Specify the 'RowTimes'
option to use the restoration times (RestorationTime
variable) as the row times, instead of the time of the power outages.
ttds = tabularTextDatastore("outages.csv","OutputType","timetable","RowTimes","RestorationTime"); preview(ttds)
ans=8×5 timetable
RestorationTime Region OutageTime Loss Customers Cause
________________ _____________ ________________ ______ __________ ___________________
2002-02-07 16:50 {'SouthWest'} 2002-02-01 12:18 458.98 1.8202e+06 {'winter storm' }
NaT {'SouthEast'} 2003-01-23 00:49 530.14 2.1204e+05 {'winter storm' }
2003-02-17 08:14 {'SouthEast'} 2003-02-07 21:15 289.4 1.4294e+05 {'winter storm' }
2004-04-06 06:10 {'West' } 2004-04-06 05:44 434.81 3.4037e+05 {'equipment fault'}
2002-03-18 23:23 {'MidWest' } 2002-03-16 06:18 186.44 2.1275e+05 {'severe storm' }
2003-06-18 10:54 {'West' } 2003-06-18 02:49 0 0 {'attack' }
2004-06-20 19:16 {'West' } 2004-06-20 14:39 231.29 NaN {'equipment fault'}
2002-06-07 00:51 {'West' } 2002-06-06 19:28 311.86 NaN {'equipment fault'}
Limitations
Datetime data containing day, month, or time zone names in a language foreign to the
en_US
locale are not supported. For unrecognized datetime formats, specify the format using theTextscanFormats
parameter.MATLAB does not support internet URLs that require authentication.
MATLAB Online™ supports internet URLs associated with Microsoft® OneDrive™ files and folders, while the installed version of MATLAB supports only local OneDrive files.
Version History
Introduced in R2014bR2024b: Read data over HTTP and HTTPS using datastore functions
You can read data from primary online sources by performing datastore operations over an internet URL.
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