Using GAMS Documentation and Model Libraries

The followings are guidelines on how to browse GAMS Documentation and Model Libraries.

Navigating and Viewing the Contents

Two main categories available for browsing are Documentation and Model Libaries.

  • Browsing Documentation
    • To start browsing, click on Documentation in the top left area of the page. Use a table of contents on the left hand side of each page to navigate through documentation.
    • To display the content of the page, click on a topic entry in the table of contents on the left hand side.
    • To either expand or hide all immediate subtopics of the topic, click on the blue arrow next in front of the topic entry.
  • Browsing Model Libaries
    • To start browsing, click on Model Libaries in the top left are of the page and select the model library of interest. Each model Library page lists all available models in a table.
    • To select the number of entries to be showed per page, select the number from a drop-down list on the top left of the table.
    • To filter the entries currently displaying in the page, type in a keyword into search box on the top right of the table.
    • To sort the entries alphabetically in either ascending order or decending order, click on the arrows in a column header of the table.

Use the Back and Forward functions in the browser to navigate the history of viewed topics, and click on Documentation or on Model Libaries to restart browsing topics from the main pages.

Searching for Contents

Searching for contents is availble for both Documentation and Model Libaries. Two different version of search are Searching for Online Contents and Search for Offline Contents. Both version is accessible by clicking on search in the top right area of the page. Unless specifying otherwise, the Documentation will be searched by default.

Searching for Online Contents

Searching for online contents is accesible via online search.

  • click on the search category below the search input box to switch between search documentation and search model libraries.
  • By default, all sections of either Documentation or Model Libaries will be searched.
  • Select a tab with a section name to narrow down the search scope.
  • Follows the following search expression rules to search the online contents:
    • The online search engine ignores character case. For example:
      GAMS 
      returns topics that contain gams, Gams, GaMs, and GAMS.
    • The search engine performs exact keyword search. For example, the keyword:
      create 
      returns hits on topics that contain create but not creates, creating, creator, and so on.
    • The search engine performs wildcard search for single character using ? and multiple characters using *. For example, the keyword:
      ga? 
      returns hits on topics that contain gap and gas but not gams.
      ga* 
      returns hits on topics that contain gap, gas, gams, gamma, gamsworkspace, and so on.
    • The search engine implies AND between all search terms. In other words, topics that contain all the search terms will be returned. For example:
      objective function 
      returns topics that contain both objective and function, but does not return topics that contain only one of these words.
    • The search engine performs boolen search using the following boolean operators: AND, OR, NOT, +, and -. For example:
      objective AND function 
      returns topics that contain both objective and function, but does not return topics that contain only one of these words.
      objective OR function 
      returns topics that contain either objective or function.
      objective NOT function 
      returns topics that contain the word objective but exclude the word function.
      +objective function 
      returns topics that must contain the word objective but may contain function.
      -objective function 
      returns topics that exclude the word objective but contian the word function.
    • The following stop words are common English words which will be ignored (not searched for) if they appear in the search expression:
      a, able, about, across, after, all, almost, also, am, among, an, and, any, are, as, at, be, because, been, but, by, can, cannot, could,  dear, did, do, does, either, else, ever, every, for, from, get, got, had, has, have, he, her, hers, him, his, how, however, i, if, in, into, is, it, its, just, least, let, like, likely, may, me, might, most, must, my, neither, no, nor, not, of, off, often, on, only, or, other, our, own, rather, said, say, says, she, should, since, so, some, than, that, the, their, them, then, there, these, they, this, tis, to, too, twas, us, wants, was, we, were, what, when, where, which, while, who, whom, why, will, with, would, yet, you, your

Search for Offline Contents

Searching for offline contents is available as a part of GAMS distribution documentation.

  • click on the search category on the top right of the page and select between searching documentation and searching model libraries.
  • By default, all sections of either Documentation or Model Libaries will be searched.
  • Select a section name from the drop-down list a section name to narrow down the search scope.
  • Follows the following search expression rules to search the offline contents:
    • The search engine ignores character case. For example:
      GAMS 
      returns topics that contain gams, Gams, GaMs, and GAMS.
    • The search engine does "fuzzy" searches and word stemming. If you enter
      create 
      it will return hits on topics that contain creates, creating, creator, and so on.
    • The search engine implis AND between all search terms. In other words, topics that contain all the search terms will be returned. For example:
      objective function 
      returns topics that contain the word objective and the word function, but does not return topics that contain only one of these words.
    • The following stop words are common English words which will be ignored (not searched for) if they appear in the search expression:
      a, able, about, across, after, all, almost, also, am, among, an, and, any, are, as, at, be, because, been, but, by, can, cannot, could,  dear, did, do, does, either, else, ever, every, for, from, get, got, had, has, have, he, her, hers, him, his, how, however, i, if, in, into, is, it, its, just, least, let, like, likely, may, me, might, most, must, my, neither, no, nor, not, of, off, often, on, only, or, other, our, own, rather, said, say, says, she, should, since, so, some, than, that, the, their, them, then, there, these, they, this, tis, to, too, twas, us, wants, was, we, were, what, when, where, which, while, who, whom, why, will, with, would, yet, you, your

To search within one document page for a specific word or phrase, use Find... (for example, CTRL+F) function in the browser.

Browsing Index for Known Keywords

Index page contains a list of interesting keywords extracted from the documentation, providing a convenient way to access the contents directly using the known keyword. Only GAMS Documentation pages are indexed and not all sections contain an index, there is no index for Model Libraries.

  • Click on Index on the top right area of each document page to start browsing index.
  • Type in a keyword into a keyword box to filter the list of all keywords.
  • Check case sensitive box to do case sensitive filtering or check Match whole word box to match the whole word.

Reloading page in a Printer-Friendly Format

Clicking on a printer-friendly verion at the bottom left of the page to reload the contents of the same page without styles and without the table of contents for navigation.

It is also possible to append a string after the url of the page in the browser navigation bar and use the browser reload function. The string is one of the followings:

  • ?print=1 - get the page contents without styles and without the table of contents for navigation
  • ?print=2 - get the page contents with styles but without the table of contents for navigation

Conventions for GAMS Syntax Representation

The syntax used to introduce features in the various chapters are presented using a format inspired by the Backus-Naur form (BNF) notation where:

Notation Description
[] the enclosed construct is optional
{} the enclosed construct may be repeated zero or more times
¦ there is an or operator across the arguments on both sides of the symbol