When you create timetables in MATLAB® code that you intend for code generation, you must create them by using the
array2timetable
, table2timetable
, or timetable
functions. For more information, see Timetables.
For timetables, code generation has these limitations:
The name of the first dimension of a timetable is 'Time'
and cannot
be changed. The name of the first dimension is also the name of the vector of row times,
which you can refer to using dot notation.
You must specify variables names by using the 'VariableNames'
name-value pair argument when creating timetables from input arrays by using the
timetable
or array2timetable
functions.
You do not have to specify the 'VariableNames'
argument when you
preallocate a timetable by using the timetable
function and the
'Size'
name-value pair argument.
Timetable variable names do not have to be valid MATLAB identifiers. The names must be composed of ASCII characters, but can include any ASCII characters (such as commas, dashes, and space characters).
After you create a timetable, you cannot change the VariableNames
,
DimensionNames
, or UserData
properties.
When you create a timetable, you can specify the 'VariableNames'
and 'RowTimes'
input arguments to set the properties having those
names.
To create a regular timetable when specifying the 'SampleRate'
,
'StartTime'
, or 'TimeStep'
name-value pair
arguments, first use the coder.Constant
function to make the values
constant. If you do not make them constant, then the row times are considered to be
irregular.
Also, if you create an irregular timetable, then it remains irregular even if you set its sample rate or time step.
If you create a regular timetable, and you attempt to set irregular row times, then an error is produced.
To pass timetable indices into generated code as input arguments, first use the
coder.Constant
function to make the indices into the second
dimension of the timetable constant. If indices into the second dimension are not
constant, then indexing into variables produces an error.
If you index into a timetable by using duration
values, or an
object produced by the timerange
or withtol
functions, then the output is nonconstant with a variable number of rows.
If you index into a regular timetable by using duration
values, or
an object produced by the timerange
or withtol
functions, then the output is considered to be irregular.
You cannot add custom metadata to a timetable. The addprop
and
rmprop
functions are not supported.
You cannot change the size of a timetable by assignments. For example, this call to add a new row produces an error.
function TT = foo() %#codegen TT = timetable((1:3)',(1:3)','RowTimes',seconds([0,5,10]),... 'VariableNames',{'Var1','Var2'}); TT{4,:} = [5,5]; end
Deleting a row or a variable by assignment also produces an error.
You cannot add a new row by using a new row time in an assignment. For example, this call to add a new row by using a new row time instead of a numeric index does not produce an error, but also does not add the new row.
function TT = foo() %#codegen TT = timetable((1:3)',(1:3)','RowTimes',seconds([0,5,10]),... 'VariableNames',{'Var1','Var2'}); TT{seconds(15),:} = [5,5]; end
When you preallocate a timetable, you can specify only the following data types by
using the 'VariableTypes'
name-value pair argument.
Data Type Name | Initial Value in Each Element |
---|---|
| Double- or single-precision |
| Double- or single-precision |
| Signed 8-, 16-, 32-, or 64-bit integer
|
| Unsigned 8-, 16-, 32-, or 64-bit integer
|
|
|
|
|
|
|
|
|
If you specify 'char'
as a data type, then
timetable
preallocates the corresponding variable as a cell array
of character vectors, not as a character array. The best practice is to avoid creating
timetable variables that are character arrays.
When you vertically concatenate timetables, they must have the same variable names in the same order. In MATLAB, the variable names must be the same but can be in different orders in the timetables.
When you horizontally concatenate timetables, they must have the same row times in the same order. In MATLAB, the row times must be the same but can be in different orders in the timetables.
If two timetables have variables that are N-D cell arrays, then you cannot vertically concatenate the timetables.
You cannot use curly braces to extract data from multiple timetable variables that are N-D cell arrays because this operation is horizontal concatenation.
The set membership functions intersect
,
setdiff
, setxor
, and
union
support unsorted timetables in all cases. You do not have to
specify the 'stable'
option.
When using the convertvars
function:
Function handles are not supported.
The second and third input arguments (vars
and
dataType
) must be constant.
You cannot specify dataType
as
'char'
.
When using the movevars
function, the input argument
vars
cannot contain duplicate variable names.
When using the isregular
function:
Use coder.Constant
to make the input argument
timeComponent
constant.
The input argument timeComponent
cannot be a calendar unit. If
you specify it, then its value must be 'time'
.
When using the retime
or synchronize
functions:
The row times of the output timetable are always considered to be irregular, even when synchronized to row times that have a regular time step.
The 'makima'
interpolation method is not supported.
If the VariableContinuity
properties of the input timetables
are not constant, then this function ignores them.
The 'weekly'
, 'monthly'
, and
'quarterly'
time steps are not supported.
If the input timetables have row times that are datetime
values, then the 'daily'
and 'yearly'
time
steps also are not supported.
When using the timerange
function, the input argument
unitOfTime
is not supported.
Limitations that apply to classes also apply to timetables. For more information, see MATLAB Classes Definition for Code Generation.
array2timetable
| table2timetable
| timetable