Expected a string scalar or character vector for the parameter name

2019 4 1
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When I try to run code for "Forecast Multiplicative ARIMA Model" example (https://es.mathworks.com/help/econ/forecast-airline-passenger-counts.html) I get the message "expected a string scalar or character vector for the parameter name".
This part works fine:
load(fullfile(matlabroot,'examples','econ','Data_Airline.mat'))
y = log(Data);
T = length(y);
Mdl = arima('Constant',0,'D',1,'Seasonality',12,...
'MALags',1,'SMALags',12);
EstMdl = estimate(Mdl,y);
but when I try:
[yF,yMSE] = forecast(EstMdl,60,y);
then i get above mentioned message.

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Adam Danz
Adam Danz 2019-4-1
Could you share the full copy-pasted error message?
Adis Hamzic
Adis Hamzic 2019-4-1
Adam, here is complete code and error:
>> load(fullfile(matlabroot,'examples','econ','Data_Airline.mat'))
>> y = log(Data);
T = length(y);
Mdl = arima('Constant',0,'D',1,'Seasonality',12,...
'MALags',1,'SMALags',12);
EstMdl = estimate(Mdl,y);
ARIMA(0,1,1) Model Seasonally Integrated with Seasonal MA(12):
---------------------------------------------------------------
Conditional Probability Distribution: Gaussian
Standard t
Parameter Value Error Statistic
----------- ----------- ------------ -----------
Constant 0 Fixed Fixed
MA{1} -0.377162 0.0667944 -5.64661
SMA{12} -0.572378 0.0854395 -6.69923
Variance 0.00126337 0.00012395 10.1926
>> [yF,yMSE] = forecast(EstMdl,60,y);
Expected a string scalar or character vector for the parameter name.

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Adam Danz
Adam Danz 2019-4-1
编辑：Adam Danz 2019-4-1

1 个投票

The help section of the forecast() function shows that there are two inputs and then you can enter optional parameter-value pairs.
help forecast
% [Y,YMSE,V] = forecast(Mdl, numPeriods, param1,val1,param2,val2,...)
If you're checking the predictive performance of the model, the paramter name you might be missing is 'Y0'.
[yF,yMSE] = forecast(EstMdl,60,'Y0',y);
% **
But check the other name-value pairs to be sure about what you're specifying here.
Recent version of matlab:
https://www.mathworks.com/help/econ/arima.forecast.html#namevaluepairs
Older versions of matlab
https://www.mathworks.com/help/releases/R2017b/econ/arima.forecast.html#bs679gg-4

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