renamevars
Description
Examples
Rename Variables in Table
Read a table from a spreadsheet. The spreadsheet provides a name for each table variable. (Read the columns containing text into table variables that are string arrays.)
T = readtable('outages.csv','TextType','string')
T=1468×6 table
Region OutageTime Loss Customers RestorationTime Cause
___________ ________________ ______ __________ ________________ _________________
"SouthWest" 2002-02-01 12:18 458.98 1.8202e+06 2002-02-07 16:50 "winter storm"
"SouthEast" 2003-01-23 00:49 530.14 2.1204e+05 NaT "winter storm"
"SouthEast" 2003-02-07 21:15 289.4 1.4294e+05 2003-02-17 08:14 "winter storm"
"West" 2004-04-06 05:44 434.81 3.4037e+05 2004-04-06 06:10 "equipment fault"
"MidWest" 2002-03-16 06:18 186.44 2.1275e+05 2002-03-18 23:23 "severe storm"
"West" 2003-06-18 02:49 0 0 2003-06-18 10:54 "attack"
"West" 2004-06-20 14:39 231.29 NaN 2004-06-20 19:16 "equipment fault"
"West" 2002-06-06 19:28 311.86 NaN 2002-06-07 00:51 "equipment fault"
"NorthEast" 2003-07-16 16:23 239.93 49434 2003-07-17 01:12 "fire"
"MidWest" 2004-09-27 11:09 286.72 66104 2004-09-27 16:37 "equipment fault"
"SouthEast" 2004-09-05 17:48 73.387 36073 2004-09-05 20:46 "equipment fault"
"West" 2004-05-21 21:45 159.99 NaN 2004-05-22 04:23 "equipment fault"
"SouthEast" 2002-09-01 18:22 95.917 36759 2002-09-01 19:12 "severe storm"
"SouthEast" 2003-09-27 07:32 NaN 3.5517e+05 2003-10-04 07:02 "severe storm"
"West" 2003-11-12 06:12 254.09 9.2429e+05 2003-11-17 02:04 "winter storm"
"NorthEast" 2004-09-18 05:54 0 0 NaT "equipment fault"
⋮
Change the names of the variables Loss
, OutageTime
, and RestorationTime
.
T = renamevars(T,["Loss","OutageTime","RestorationTime"], ... ["Total Cost","Start of Outage","Restoration"])
T=1468×6 table
Region Start of Outage Total Cost Customers Restoration Cause
___________ ________________ __________ __________ ________________ _________________
"SouthWest" 2002-02-01 12:18 458.98 1.8202e+06 2002-02-07 16:50 "winter storm"
"SouthEast" 2003-01-23 00:49 530.14 2.1204e+05 NaT "winter storm"
"SouthEast" 2003-02-07 21:15 289.4 1.4294e+05 2003-02-17 08:14 "winter storm"
"West" 2004-04-06 05:44 434.81 3.4037e+05 2004-04-06 06:10 "equipment fault"
"MidWest" 2002-03-16 06:18 186.44 2.1275e+05 2002-03-18 23:23 "severe storm"
"West" 2003-06-18 02:49 0 0 2003-06-18 10:54 "attack"
"West" 2004-06-20 14:39 231.29 NaN 2004-06-20 19:16 "equipment fault"
"West" 2002-06-06 19:28 311.86 NaN 2002-06-07 00:51 "equipment fault"
"NorthEast" 2003-07-16 16:23 239.93 49434 2003-07-17 01:12 "fire"
"MidWest" 2004-09-27 11:09 286.72 66104 2004-09-27 16:37 "equipment fault"
"SouthEast" 2004-09-05 17:48 73.387 36073 2004-09-05 20:46 "equipment fault"
"West" 2004-05-21 21:45 159.99 NaN 2004-05-22 04:23 "equipment fault"
"SouthEast" 2002-09-01 18:22 95.917 36759 2002-09-01 19:12 "severe storm"
"SouthEast" 2003-09-27 07:32 NaN 3.5517e+05 2003-10-04 07:02 "severe storm"
"West" 2003-11-12 06:12 254.09 9.2429e+05 2003-11-17 02:04 "winter storm"
"NorthEast" 2004-09-18 05:54 0 0 NaT "equipment fault"
⋮
Append Suffix to Table Variable Names
Create a table with many variables by using the array2table
function. Add names for the variables.
T = array2table(rand(5,5))
T=5×5 table
Var1 Var2 Var3 Var4 Var5
_______ _______ _______ _______ ________
0.81472 0.09754 0.15761 0.14189 0.65574
0.90579 0.2785 0.97059 0.42176 0.035712
0.12699 0.54688 0.95717 0.91574 0.84913
0.91338 0.95751 0.48538 0.79221 0.93399
0.63236 0.96489 0.80028 0.95949 0.67874
Change the variable names so that they each start with "Reading"
and end with a suffix. Determine how many variables T
has by using the width
function. Specify the table variables as a numeric array.
Convert the numeric array allVars
to a string array. Create a 1-by-5 string array by appending each element to "Reading"
.
Rename all of the variables by using the renamevars
function.
allVars = 1:width(T);
newNames = append("Reading",string(allVars));
T = renamevars(T,allVars,newNames)
T=5×5 table
Reading1 Reading2 Reading3 Reading4 Reading5
________ ________ ________ ________ ________
0.81472 0.09754 0.15761 0.14189 0.65574
0.90579 0.2785 0.97059 0.42176 0.035712
0.12699 0.54688 0.95717 0.91574 0.84913
0.91338 0.95751 0.48538 0.79221 0.93399
0.63236 0.96489 0.80028 0.95949 0.67874
Input Arguments
T1
— Input table
table | timetable
Input table, specified as a table or a timetable.
vars
— Variables in input table or timetable
character vector | string array | cell array of character vectors | pattern
scalar | numeric array | logical array | subscript object
Variables in the input table or timetable, specified as a character vector, string
array, cell array of character vectors, pattern
scalar, numeric array, logical array, or subscript object.
You can specify vars
as a subscript object that detects variables
of a specified data type by using the vartype
function.
Example: T = renamevars(T,'Var1','Location')
changes the name of
the table variable 'Var1'
to
'Location'
.
Example: T =
renamevars(T,["Var1","Var2"],["Latitude","Longitude"])
changes the names of
two table variables.
Example: T = renamevars(T,1:width(T),newNames)
renames all of the
table variables. The width of a table, returned by the width
function, equals the number of its variables.
Example: vars = vartype('numeric'); T =
renamevars(T,vars,newNames)
renames all of the numeric variables in
T
.
newNames
— New names for variables
character vector | string array | cell array of character vectors
New names for variables, specified as a character vector, string array, or cell array of character vectors.
The number of names specified by newNames
must match the number
of variables specified by vars
.
Tips
You can also rename all of the variables in a table by setting its
VariableNames
property, as inT.Properties.VariableNames = newNames
. In that case,newNames
must be a string array or a cell array of character vectors.
Extended Capabilities
Tall Arrays
Calculate with arrays that have more rows than fit in memory.
The
renamevars
function fully supports tall arrays. For more information,
see Tall Arrays.
C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.
Thread-Based Environment
Run code in the background using MATLAB® backgroundPool
or accelerate code with Parallel Computing Toolbox™ ThreadPool
.
This function fully supports thread-based environments. For more information, see Run MATLAB Functions in Thread-Based Environment.
Distributed Arrays
Partition large arrays across the combined memory of your cluster using Parallel Computing Toolbox™.
This function fully supports distributed arrays. For more information, see Run MATLAB Functions with Distributed Arrays (Parallel Computing Toolbox).
Version History
Introduced in R2020a
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