Analizar datos
Antes de comenzar a estimar modelos a partir de los datos seleccionados, debe comprobar si los datos tienen alguna característica indeseable para determinar la necesidad de preprocesar los datos. Puede hacerlo:
Representando los datos para examinar el comportamiento tanto en el dominio del tiempo como en el dominio de la frecuencia.
Usando el comando
advicepara analizar si en los datos hay desplazamientos y tendencias constantes, retrasos, posible retroalimentación y niveles de señales.
Funciones
bode | Respuesta en frecuencia de Bode de un sistema dinámico |
bodemag | Magnitude-only Bode plot of frequency response |
idplot | Plot input and output channels of estimation data (Desde R2023a) |
advice | Analysis and recommendations for data or estimated linear models |
delayest | Estimate time delay (dead time) from data |
isreal | Determine whether model parameters or data values are real |
realdata | Determine whether iddata is based on
real-valued signals |
checkFeedback | Identify possible feedback data (Desde R2023a) |
pexcit | Level of excitation of input signals |
impulseest | Nonparametric impulse response estimation |
etfe | Estimate empirical transfer functions and periodograms |
spa | Estimate frequency response with fixed frequency resolution using spectral analysis |
spafdr | Estimate frequency response and spectrum using spectral analysis with frequency-dependent resolution |
dataPlotOptions | Option set for idplot when plotting input/output estimation data
contained in a timetable, numeric matrices, or an iddata
object (Desde R2023a) |
Temas
- Is Your Data Ready for Modeling?
Before you start estimating models from data, you should check your data for the presence of any undesirable characteristics.
- How to Plot Data in the App
After importing data into the System Identification app, as described in Representar datos, you can plot the data.
- How to Plot Data at the Command Line
The following table summarizes the commands available for plotting time-domain, frequency-domain, and frequency-response data.
- Identify Delay Using Transient-Response Plots
You can use transient-response plots to estimate the input delay, or dead time, of linear systems.
- How to Analyze Data Using the advice Command
You can use the
advicecommand to analyze time- or frequency- domain data before estimating a model.