Time to Frequency FFT
A Time to Frequency FFT study step, which you can add to a frequency domain study, performs a forward FFT from the time domain (input) to the frequency domain (output). As the default solver it adds an FFT solver.
Syntax
model.study(stdname).create(fname, "TimeToFreqFFT");
model.study(stdname).feature(fname).set(pname,value);
Description
Study step.
The following properties are available.
Table 6-180: Properties for Study Settings.
Property
Value
Default
Description
fftendtime
Real scalar
1.0
End time for the time interval.
fftmaxfreq
Real scalar
10
Maximum output frequency.
fftrealstore
on | off
on
Do not store negative frequencies for real input.
fftscaling
cont | discrete
cont
Use a discrete or continuous scaling for the Fourier transform.
fftstarttime
Real scalar
0.0
Start time for the time interval.
fftwinalpha
Real scalar
0.5
Window parameter for a Tukey window.
fftwincenterfw
Real scalar
0.5
Window center for a Gaussian window function.
fftwincutoff
Real scalar
1
Cutoff fraction for window function in [0, 1].
fftwindev
Real scalar
1
Standard deviation for a Gaussian window function.
fftwindowfw
on | off
off
Use window function.
fftwinexpr
String
1
Expression for window function (when set to fromexpr). Can be expressed in terms of t, freq, niterFFTin, and niterFFTout (if applicable).
fftwinmaxfw
Real scalar
1
Maximum (end) value for window.
fftwinminfw
Real scalar
0
Minimum (start) value for window.
fftwintypefw
fromexpr | cutoff | rectangle | gauss | hamming | hanning | blackman | tukey
fromexpr
Method for window function.
linpmethod
sol | init
sol
Prescribe the input values using a solution or an initial expression.
linpsol
String
 
Solution that defines input values for the FFT study step.
linpsoluse
String
 
Subsolution that defines the input values for the FFT study step/FFT solver.
linpstudy
String
 
Study that defines input values for the FFT study step.
punit
String
Hz
Frequency unit.
tunit
String
s
Time unit.
Table 6-181: Properties for Physics and Variables Selection.
Property
Value
Default
Description
activate
String Map
 
See Physics and Variables Selection.
activateCoupling
String Map
 
See Physics and Variables Selection.
activaterom
String Map
 
See Physics and Variables Selection.
disabledcommon
Reference Array
 
See Physics and Variables Selection.
disabledcoordinatesystems
Reference Array
 
See Physics and Variables Selection.
disabledcoupling
Reference Array
 
See Physics and Variables Selection.
disabledpair
Reference Array
 
See Physics and Variables Selection.
disabledphysics
Reference Array
 
See Physics and Variables Selection.
disabledreduced
Reference Array
 
See Physics and Variables Selection.
disabledvariables
Reference Array
 
See Physics and Variables Selection.
disableFrameControl
Reference Array
 
See Physics and Variables Selection.
discretization
String Map
 
See Physics and Variables Selection.
equationform
String Map
 
See Physics and Variables Selection.
equationform_freq
String Map
 
See Physics and Variables Selection.
equationform_freq_src
String Map
 
See Physics and Variables Selection.
reconstructors
String Map
 
See Physics and Variables Selection.
useadvanceddisable
on | off
off
See Physics and Variables Selection.
Table 6-182: Properties for Values of Dependent Variables.
Property
Value
Default
Description
notlistsolnum
Vector of integers
[1]
Indices to selected solutions for values for variables not solved for.
notmanualsolnum
Vector of integers
[1]
Indices to solutions for values for variables not solved for.
notsolmethod
init | sol
init
Method for values for variables not solved for.
notsolnum
auto | all | first | last | from_list | interp | manual | positive integer
auto
Solution selection for values for variables not solved for.
notstudy
String
 
Reference to study or "zero" for zero solution.
nott
String
 
Specify time for interpolated solution of values for variables not solved for.
outputInterface
The interfaces to use as key
 
An output property for the physics interfaces in the output. It can be used as keys while setting the outputmap and outputselectionmap.
outputmap
String Map
 
See Store in Output for possible options and defaults (this property corresponds to the Output column). Possible values are physics, all, none, or selection.
outputselectionmap
String Map
 
A semicolon-separated string array of the output selections (specified with tags).
See setEntry() for information about setting the values for a property that uses a String Map. If you use the set(pname,value) method, you have to provide all alternating property name and property value pairs.
Table 6-183: Property for Mesh selection.
Property
Value
Default
Description
mesh
Vector of strings
 
Select meshes for geometries. The length of the vector is two times the number of geometries. Example value when two geometries geom1 and geom2 are available is: new String[]{"geom1","mesh1","geom2", "mesh2"}.