Commands of SCA useful for Analysis of Financial Time Series: Comment starts with the character ``--''. Optional commands are in square brackets. -- to save output into a file called ``scaoutp.otp'' profile review. [owidth 80] -- to load a single column of data from file ``fname.dat'' into SCA workspace -- Below xxx denotes any variable name of your choice. input xxx. file 'fname.dat' -- to load multiple columns (say 3) from file ``fname.dat'' into SCA -- Format is the usual FORTRAN format. -- Variable names x1,x2,x3 are selected by user. input x1,x2,x3. file 'fname.dat'. [format '(4x,3f10.4)'] -- to obtain descriptive statistics of variable x1 desc x1 -- to quit SCA stop -- to stop a command due to typos (but remain in SCA) quit -- to compuate ACF of variable x1. The number of lags canbe chosen. axf x1. [maxlag 12] -- to compute PACF of variable x1 pacf x1. [maxlag 12] -- to compute ACF and PACF of variable x1 iden x1. [maxlag 12] -- to compute EACF of variable x1 eacf x1. -- to do an automatic ARMA model selection for variable x1 -- If the series is seasonal, give the periodicity xxx. iarima x1. [seas xxx] -- to specify an ARMA(2,1) model and call the model model1 for variable x1. -- numerical numbers inside the parentheses in front of x1 denotes the -- autoregressive lags used. No parentheses are needed if no AR part. -- The existence of c1 means the model contains a constant term. -- numerical numbers inside the parentheses before noise denotes the -- moving-average lags used. -- noise means the shock or innovation in SCA tsm model1. model (1,2)x1=c1+(1)noise. -- to estimate the specified model ``model1'' and hold residuals in ``r1'' estim model1. hold resi(r1). [method exact] -- to produce forecast using model ``model1'' at forecast orign nn. -- ``nofs'' denotes the number of forecasts needed, i.e. forecast horizon. -- default nofs is 24. -- default forecast origin is the end of data points. fore model1. [nofs xx.] [orig nn] -- to obtain the roots of a fitted ARMA model ``model1''. tsm model1. roots. -- natural log transformation y = ln(x). y=ln(x) -- Basically, SCA allows arithematic operations as usual, e.g. -- transform a log return in percentage into a simple return in percentage y=100*(exp(x1/100)-1) -- to obtain the squared series of a time series x1. y=x1*x1 -- to obtain the absolute series of a time series x1. y=abs(x1) -- to obtain psi-weight and pi-weight of a fitted ARMA model -- store the psi-weight in psi and the piweight in pi. weight model1. psiweight psi. piweight pi. [cutoff 0.001] -- to specify a regression model with time series errors -- assume the regression is y=b0 + b1*x1 + b2*x2 and the time series -- error follows an ARMA(2,1) model. -- call the model ``m2''. In front of the ``noise'', numerator denotes -- the moving-average part and denominator the autoregressive part. -- If no MA model is needed, then use 1/(1,2)noise. tsm m2. model y=b0 + (b1)x1 + (b2)x2 + (1)/(1,2)noise. -- to compute correlations between variables x1,x2,x3. corr x1, x2, x3. Finally, once you exit SCA. The output file ``scaoutp.otp'' is in your directory. You may rename it if you like to keep it. On GSBMBA use the following command to rename it ``solut.otp''. mv scaoutp.otp solu1.otp