Forecasting Prices with Learning Machine

Hello. I am new to Learning machine development. In short, I want to do the following: I have some product prices for 216 and I want to make forecast using learning machine for the prices of this product for the first 3 months of 2017. I created the training and testing set data. Then I traned the network. But I have not been able to forecast. I used command forecast but makes an error.

Below I have the code I wrote for creating the training and testing set data. Tour help is invaluable!!!

t=linespace(-5,5,length(PriceData2016));
trials=20;
neurals=20;
for i=1:trials
    %Training Data
    samples=1
    DataPrices=length(PriceData2016);
    TrainxData=t(ones(1,samples),:)';
    TrainingyData=sinc(TrainxData'/pi)+(-0.2 +0.4*rand(samples,Dataprices2013));
    %Testing Data
    TestingxData=t;
    TestingyData=h*bet;
end
%train network
train=false;
if train || ~ exist('Model.mat','file')
    net=mewfit(TrainingxData',TrainingyData',20);
    net.perform='mae';
    net=train(net, TrainigxData',TrainingyData');
    save Model.mat net
    elese
    load Model. mat
end
%Price forecasting
forecastPrice2017=forecast(net,length(PriceData2016),'Y0',TestingxData)

error: undefiined function 'forecast' for input arguments of type network.

For the forecasting I tried the following command but it did not work.

forecastinPrice2017=sim(sim,TetingxData');

error:Input data sizes do not match net.input{1}.size

sizes of matrix:

TrainingxData: 250X1

TrainingyData: 1X250

TestingxData: 1X250

TestingyData: 1X250