G7 Commands: H¶
- help
The help command can be given from the G7 command box, in which case it will bring up the G7 Help files. Contents include the G7 User Guide, Reference Manual, and the Tutorial, plus manuals for Compare, Fixer and MacFixer, Banker, and IdBuild.
Related Topics: Help Menu
- hbk <bank_name> <bank_location>
The hbk command assigns a hashed bank (.HBK, .HIN). The optional <bank_location> parameter may be any letter between ‘a’ and ‘z’ except ‘w’. If no letter is given, the position will be ‘a’. The hashed bank comes in two files. The first file, with an extension .HBK, holds the data series in compressed format, and the second file, with extension .HIN, holds a hash table that allows quick access to a large number of series. When you give the <bank_name> to the hbk command, give only the “rootname” of the file, that is, without the file extension.
Note that when you do a listnames command on a hashed bank, the series names will not be in the order in which the bank was created by the Banker program. This is because the hashing algorithm puts the series names into various “bins”, based on the hash value of the series name. When reading the series names back again, G7 just goes through each bin in sequence, which is not the sequence in which the bank was created. See the Banker manual for more on how to create compressed and hashed banks.
Related Topics: Assigned Banks, Using Banker, bank, cbk, dfr, listbanks, vam
- (hes)itate < y | n >
This command is almost the opposite of the zip command. If you give “hes y”, then G7 will pause before displaying each regression so that you can read the commands that prepared the regression. To turn off hesitation, use “hes n”. Remember that if you wish to have the add file stop so that you can see what has just gone by on the screen, use the pause command in your add file.
- hl <rho1> <rho2> <incr> <y> = <x1>, [<x2>,] [<x3>,] …[<xn>]
The hl command applies the Hildreth-Lu procedure for correcting for serial correlation of errors. It is a special case of Generalized Least Squares (GLS). In the Hildreth-Lu procedure, a guess of the autocorrelation coefficient of the errors, rho, is chosen, multiplied by the equation lagged once, and subtracted from the unlagged equation. The resulting equation then is estimated by ordinary regression. Another value of the guess of rho then is chosen and the process is repeated. In this command, <rho1> is the starting guess of rho, <incr> is the amount by which it is changed on each iteration, and <rho2> is an upper limit on the guess. The <y> and <x1>, …, <xn> are as in the r command. At the end of the process, you will get a table with this heading:
RHO-HL SEE 1 AHEAD RHO-EST SEE LONG-RUN
The RHO-HL shows the assumed rho, the SEE 1 AHEAD shows the standard error of estimate (SEE) of the estimated equation, RHO-EST shows the rho of the estimated equation, and SEE LONG-RUN shows the standard error of using the fitted equation on the original, undifferenced data, without a knowledge of the true lagged value of the dependent variable, as must be done in forecasts of more than a few periods ahead. If the save command is on, all of the estimated equations will placed in the “.SAV” file as undifferenced equations suitable for going into a model. You must choose which one you want.
For graphing the hl output, one should run the equation one last time with the chosen value of rho as both the starting and ending rho. Then also run the equation with just the r command (no autocorrelation)0. Then construct two graphs:
gr depvar predp1 hlshort gr depvar predic hllong
The first will compare the actual with two one-period ahead forecasts, the one from ordinary least squares (+’s) and one from Hildreth-Lu (x’s). The second compares the actual with two forecasts not relying on the lagged value of the dependent variable. Again, the un-corrected least squares fit is shown by +’s and the fit using the Hildreth-Lu correction is shown by x’s.
The pauses at the end of each fit in the HL procedure can be eliminated by the zip command. If you use zip, however, you must remember to do “zip off” before using the graph command in order to see graphs.
For example,
ti The Phillips Curve subti from 70.1 to 96.1 gdates 70.1 96.1 vaxl out vaxti Inflation legend s vr 0 2 4 6 8 10 12 hr 4 6 8 10 12 f infl = 400*(dgdp - dgdp[1])/dgdp[1] sgr infl unempcIn this example, inflation (infl) is measured on the vertical axis, which runs from 0 to 12, and unemployment (unempc) is measured on the horizontal axis, which runs from 4 to 12. Axis labels and tick marks on both axes are every two percentage points.
