mergevars - Combine table or timetable variables into multicolumn variable - MATLAB (original) (raw)
Combine table or timetable variables into multicolumn variable
Syntax
Description
T2 = mergevars([T1](#d126e1092026),[vars](#d126e1092045)) combines the table variables specified by vars to create one multicolumn variable in T2. All other variables fromT1 are unaltered. You can specify variables by name, by position, or using logical indices.
For example, if T1 has variables named var3 and var5, then you can combine them into a variable that has two columns by using T2 = mergevars(T1,["var3","var5"]).
By default, the name of the merged variable in T2 takes the form Var_`N`_, where_`N`_ is the position of the merged variable. For example, if the merged variable is the third variable inT2, then its name is Var3.
To split multicolumn variables, use the splitvars function.
T2 = mergevars([T1](#d126e1092026),[vars](#d126e1092045),[Name,Value](#namevaluepairarguments)) specifies options using one or more name-value arguments in addition to the input arguments in the previous syntax. For example, to specify a name for the merged variable, set NewVariableName to the name that you specify.
Examples
Create a table from workspace variables.
A = [1:3]'; B = [5 11 12]'; C = [3.14 2.72 1.37]'; D = ["a";"b";"c"]; T1 = table(A,B,C,D)
T1=3×4 table A B C D _ __ ____ ___
1 5 3.14 "a"
2 11 2.72 "b"
3 12 1.37 "c"Merge the second and third variables. The new variable has two columns.
T2=3×3 table A Var2 D _ __________ ___
1 5 3.14 "a"
2 11 2.72 "b"
3 12 1.37 "c"Create a table using arrays of data from the patients.mat file.
load patients T1 = table(Age,Height,Weight,Systolic,Diastolic)
T1=100×5 table Age Height Weight Systolic Diastolic ___ ______ ______ ________ _________
38 71 176 124 93
43 69 163 109 77
38 64 131 125 83
40 67 133 117 75
49 64 119 122 80
46 68 142 121 70
33 64 142 130 88
40 68 180 115 82
28 68 183 115 78
31 66 132 118 86
45 68 128 114 77
42 66 137 115 68
25 71 174 127 74
39 72 202 130 95
36 65 129 114 79
48 71 181 130 92
⋮Merge the variables Systolic and Diastolic into one variable with two columns. Name it BloodPressure.
T2 = mergevars(T1,["Systolic","Diastolic"], ... "NewVariableName","BloodPressure")
T2=100×4 table Age Height Weight BloodPressure ___ ______ ______ _____________
38 71 176 124 93
43 69 163 109 77
38 64 131 125 83
40 67 133 117 75
49 64 119 122 80
46 68 142 121 70
33 64 142 130 88
40 68 180 115 82
28 68 183 115 78
31 66 132 118 86
45 68 128 114 77
42 66 137 115 68
25 71 174 127 74
39 72 202 130 95
36 65 129 114 79
48 71 181 130 92
⋮Read a table from a spreadsheet. To specify the data types of the columns that you read from the spreadsheet, use an import options object. Display the first eight rows of the output table.
opts = detectImportOptions("outages.csv"); opts.VariableTypes = ["categorical","datetime","double", ... "double","datetime","categorical"]; T1 = readtable("outages.csv",opts)
T1=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
⋮Merge Cause, Loss, and RestorationTime. Because these variables have different types, merge them into a table that is nested in the output table.
T2 = mergevars(T1,["Cause","Loss","RestorationTime"],... "NewVariableName","LossData","MergeAsTable",true)
T2=1468×4 table
Region OutageTime Customers LossData
_________ ________________ __________ _____________________________________________
Cause Loss RestorationTime
_______________ ______ ________________
SouthWest 2002-02-01 12:18 1.8202e+06 winter storm 458.98 2002-02-07 16:50
SouthEast 2003-01-23 00:49 2.1204e+05 winter storm 530.14 NaT
SouthEast 2003-02-07 21:15 1.4294e+05 winter storm 289.4 2003-02-17 08:14
West 2004-04-06 05:44 3.4037e+05 equipment fault 434.81 2004-04-06 06:10
MidWest 2002-03-16 06:18 2.1275e+05 severe storm 186.44 2002-03-18 23:23
West 2003-06-18 02:49 0 attack 0 2003-06-18 10:54
West 2004-06-20 14:39 NaN equipment fault 231.29 2004-06-20 19:16
West 2002-06-06 19:28 NaN equipment fault 311.86 2002-06-07 00:51
NorthEast 2003-07-16 16:23 49434 fire 239.93 2003-07-17 01:12
MidWest 2004-09-27 11:09 66104 equipment fault 286.72 2004-09-27 16:37
SouthEast 2004-09-05 17:48 36073 equipment fault 73.387 2004-09-05 20:46
West 2004-05-21 21:45 NaN equipment fault 159.99 2004-05-22 04:23
SouthEast 2002-09-01 18:22 36759 severe storm 95.917 2002-09-01 19:12
SouthEast 2003-09-27 07:32 3.5517e+05 severe storm NaN 2003-10-04 07:02
West 2003-11-12 06:12 9.2429e+05 winter storm 254.09 2003-11-17 02:04
NorthEast 2004-09-18 05:54 0 equipment fault 0 NaT
⋮Input Arguments
Input table, specified as a table or timetable.
Variables in the input table, specified as a string array, character vector, cell array of character vectors, pattern scalar, numeric array, or logical array.
Name-Value Arguments
Specify optional pairs of arguments asName1=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: T2 = mergevars(T1,vars,NewVariableName="MergedResults")
Before R2021a, use commas to separate each name and value, and enclose Name in quotes.
Example: T2 = mergevars(T1,vars,"MergeAsTable",true)
Name of the merged variable, specified as a character vector or string scalar.
Flag to merge variables into a table, specified as a numeric or logical 1 (true) or0 (false). Set this flag totrue or 1 to merge the specified variables into a table that is nested into a variable of the output table. Use this argument to combine variables that cannot be concatenated into an array.
The default value of false causesmergevars to merge the specified variables into one multicolumn array that is a variable of the output table.
Extended Capabilities
Themergevars function fully supports tall arrays. For more information, see Tall Arrays.
Usage notes and limitations:
- The
varsinput argument does not support pattern expressions.
Version History
Introduced in R2018a