Gekko User Manual > Gekko statements

Note: You may consult the specialized overviews regarding data handling and modeling:

Introduction

Below, all Gekko statements are listed, grouped together by functionality (regarding functions, see the section on these: 'Gekko functions').

Databanks

At startup, Gekko operates with two databanks; 'Work' (first-position, working bank) and 'Ref' (reference, baseline bank). There are the following statements related to databanks:

READ	Reads a databank file (typically gbk) into the first-position and reference databanks.
WRITE	Writes the first-position databank to a gbk file
IMPORT	Merges a databank file (typically non-gbk) into the first-position databank
EXPORT	Writes the first-position databank to a non-gbk file
OPEN	Opens a databank file (typically gbk). May use OPEN<edit> or OPEN<ref>.
CLOSE	Closes 'named' databanks (cf. OPEN)
CLONE	Makes the reference databank an exact copy of the first-position databank.
DOWNLOAD	Retrieves timeseries from a web-based database
COPY	Copies timeseries between banks (or inside the first-position databank)
RENAME	Renames timeseries.
INDEX	Uses wildcards to search for timeseries in databanks.
COUNT	Uses wildcards to count timeseries in databanks.
COMPARE	Finds differences between the first-position and reference databanks.
FINDMISSINGDATA	This statement finds timeseries with missing values.
HDG	Inserts a heading (description) into a gbk databank
UNLOCK	Sets a databank editable
LOCK	Sets a databank non-editable

Timeseries

Timeseries exist as objects in a databank. Frequency can be annual, quarterly, monthly, weekly, daily or undated.

TIME	Sets global time for timeseries operations.
TIMEFILTER	Omits or averages certain periods in output
CREATE	Create a new timeseries
DELETE	Delete an existing timeseries
SERIES	Transform a timeseries using mathematical expressions or data values
COLLAPSE	Convert e.g. quarterly timeseries into annual timeseries etc.
INTERPOLATE	Convert e.g. annual timeseries into quarterly timeseries etc.
SMOOTH	Fills in missing values in a timeseries
SPLICE	Splices two timeseries into one.
REBASE	Calculates an index series
TRUNCATE	Removes observations in a timeseries outside the stated sample.
ANALYZE	Computes cross-correlations etc.
DOC	Change meta information (label, source and date stamp)

Lists, scalars, matrices etc.

Gekko can put names of timeseries into a list, in order to reuse the list for different purposes (or make the program file easier to read). In addition, scalar variables like strings, dates and values can be used.

LIST	Create and delete lists
DATE	Scalar variable of date type
STRING	Scalar variable of string type
VAL	Scalar variable of value type
MATRIX	Define a matrix
MEM	Shows a list of scalar variables and their values

Show data

Gekko can show data in several ways, including printing on the screen, graphs, or showing the data in an Excel sheet. In addition, there is a special table-like decomposition window (DECOMP). The DISP statement also functions as an in-built equation browser. You may prefix a variable with '@' to indicate the reference ('Ref') databank, for instance @gdp. Or else use colon to indicate a databank, for instance mybank:gdp.

PRT	Prints timeseries or expressions in different ways
MULPRT	Prints multipliers: differences between the first-position and reference databanks.
DISP	Prints info regarding timeseries, and starts equation browser
PLOT	Show a graph of timeseries (using gnuplot)
SHEET	Like PRT, but shows timeseries data in Excel
CLIP	Like PRT, but puts timeseries data on the Windows clipboard
DECOMP	Decompose an equation
FIND	Find a variable in equations
FLOW	Show a flowgraph corresponding to a DECOMP statement
TELL	Prints text strings on the screen
TRACE	Show data-traces (timeseries)

Model

A model can be loaded directly from a .frm file. After the model is loaded, a number of statements can be used:

MODEL	Load, parse and compile a model from file.
SIM	Simulates the model (also if there are goals/means)
ENDO	Endogenize variables (means)
EXO	Exogenize variables (goals)
UNFIX	Removes ENDO/EXO goals/means.
PREDICT	Single-equation prediction
CHECKOFF	Skip convergence check for chosen variables (Gauss)
ITERSHOW	Show iterations in detail for chosen variable (Gauss)
SIGN	For signing models with signatures.

Gekko program files

Larger tasks can be run by means of program files (.gcm). There are the following statements related to such files:

RUN	Runs a .gcm program file. Use the EDIT statement to edit these files.
PIPE	Direct output to an external file instead of screen
INI	Runs gekko.ini if located in the program and/or working folder

Functions/procedures

You may use user-defined functions or procedures to avoid repetitive tasks and encapsulate functionality.

FUNCTION	Defines a user-defined function.
PROCEDURE	Defines a user-defined procedure.
LIBRARY	Store functions/procedures inside a library .zip file for general use.

Cleanup

The principal cleanup-statement is the following

RESTART	Clears all databanks, lists, scalars, models, etc. and runs any gekko.ini files.
RESET	Same as RESTART, but without running any gekko.ini files.
CLEAR	Clearing databanks
CLOSEALL	Closes all 'named' databanks, and clears Work and Ref.
CLS	Clears main window (short for 'clear screen')
CUT	Closes all PLOT and DECOMP windows

Control flow

Gekko supports basic control flow like loops, conditional statements etc. At the moment the possibilities are quite limited, but will be augmented as the software matures.

FOR	For-loop over lists/strings, values or dates, parallel loops are possible.
IF	Conditional statement (IF-ELSEIF-ELSE-END).
END	Ends loop (FOR), conditional statement (IF) or FUNCTION/PROCEDURE.
RETURN	Returns from the program file or function defintion.
STOP	Stops execution completely.
EXIT	Stops execution completely, and terminates Gekko.
ACCEPT	Input data interactively
PAUSE	Waiting for the user to click [Enter]
GOTO	Transfers execution to the corresponding TARGET
TARGET	Receives execution from the corresponding GOTO

Tables/menus

TABLE	Prints out a predefined table (xml)
MENU	Opens up a menu (html)

Econometrics

OLS	Single-equation linear regression

Python and R interfaces

PYTHON_RUN	Runs the decorated Python file, and returns matrices back to Gekko
R_RUN	Runs the decorated R file, and returns matrices back to Gekko

Miscellaneous

The following statements did not fall into the above categories, and so are gathered here:

MODE	Set Gekko mode to sim/data/mixed
HELP	Access the help system
OPTION	Sets different options
GEKKO	Indicate a particular Gekko version
EDIT	Edit a file via Notepad
XEDIT	Edit a xml file via XML Notepad.
SYS	Access the system shell if needed
TRANSLATE	Translates syntax from Gekko 1.8 or AREMOS

From the menu items (‘Utilities’), you can also compare two databanks, check residuals, and compare variables in model/databank/varlist.

Statements overview

Statements overview