renamevars - Rename variables in table or timetable - MATLAB (original) (raw)
Rename variables in table or timetable
Syntax
Description
T2 = renamevars([T1](#mw%5Feb6227ae-f262-4a75-b383-98fb32ed2153),[vars](#mw%5F65012b2a-2402-46b6-8552-6a412ec1b2d4),[newNames](#mw%5F5113dd04-5d01-41b9-bb58-3a6a940ba9dc)) renames the table or timetable variables specified by vars using the names specified by newNames.
Examples
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"
⋮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 0.67874Change 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 0.67874Input Arguments
Input table, specified as a table or a timetable.
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 inT.
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
VariableNamesproperty, as in_T_.Properties.VariableNames =_newNames_. In that case,_newNames_must be a string array or a cell array of character vectors.
Extended Capabilities
Therenamevars function fully supports tall arrays. For more information, see Tall Arrays.
Version History
Introduced in R2020a