Search found 137 matches

by aileen
4 weeks ago
Forum: Tools
Topic: Reading Sets from Excell Sheets with Connect
Replies: 1
Views: 760

Re: Reading Sets from Excell Sheets with Connect

Hi raphael, From you Excel sheet snippet and the Connect code it is not very clear to me what you are trying to achieve. From the Excel sheet snippet it looks like you are trying to read a 3-dimensional set where the labels are found in A2:C4 . But in the Connect code you specified a data range of A...
by aileen
1 month ago
Forum: Syntax
Topic: Pandas Excel Writer on macOS
Replies: 4
Views: 2903

Re: Pandas Excel Writer on macOS

With the GAMS 46 release the PandasExcelWriter is deprecated and it is recommended to use the new ExcelWriter instead. The ExcelWriter has an option mergedCells that allows to control the writing of merged cells (per default no merged cells will be written). Just as the PandasExcelWriter, the ExcelW...
by aileen
1 month ago
Forum: Tools
Topic: Data exchange from excel to gams (on macOS)
Replies: 6
Views: 8377

Re: Data exchange from excel to gams (on macOS)

With the GAMS 46 release the PandasExcelReader is deprecated and it is recommended to use the new ExcelReader instead. The ExcelReader has the same functionalities as the PandasExcelReader but removes some limitations (e.g. the requirement for artificial indices) and adds some new features (e.g. ski...
by aileen
1 year ago
Forum: Syntax
Topic: Pandas Excel Writer on macOS
Replies: 4
Views: 2903

Re: Pandas Excel Writer on macOS

Hi Marco, The PandasExcelWriter is based on the pandas.DataFrame class and its I/O API method to_excel . pandas.to_excel per default writes merged cells but allows to change this behavior via the option merge_cells . You can pass merge_cells: False via toExcelArguments as follows: set i /i1*i2/; set...
by aileen
1 year ago
Forum: Tools
Topic: Data exchange from excel to gams (on macOS)
Replies: 6
Views: 8377

Re: Data exchange from excel to gams (on macOS)

Hi Marco, GAMS Connect is a new platform independent tool set to read data from a range of external sources (including Excel), transform it, and make it available to GAMS models. This will be the future for data connectivity in GAMS. We already announced the retirement of a couple of older data tool...
by aileen
2 years ago
Forum: GAMS-FAQ
Topic: GAMS User Groups
Replies: 0
Views: 6369

GAMS User Groups

Besides GAMS World Forum, there are other user groups that allow GAMS users worldwide to exchange information about GAMS:
by aileen
2 years ago
Forum: Tools
Topic: The good source for learning ScenRed
Replies: 1
Views: 6714

Re: The good source for learning ScenRed

Hi, If you want to learn the tool SCENRED/SCENRED2 for scenario reduction take a look at the documentation of the tool (see SCENRED documentation and SCENRED2 documentation ). The documentation also provides you with a short description of the algorithms used and references of papers the tool is bas...
by aileen
2 years ago
Forum: GAMS-FAQ
Topic: How do I formulate logical expressions in equations?
Replies: 0
Views: 7377

How do I formulate logical expressions in equations?

GAMS does not reformulate logical expressions. You need to do this by hand. A common way to model logical expressions is using the so-called big-M method. The interested reader is referred to the book by H.P. Williams on Model Building in Mathematical Programming. It explains how to use the big-M me...
by aileen
2 years ago
Forum: GAMS-FAQ
Topic: Linearize a nonlinear function using piecewise linear approximation
Replies: 0
Views: 6911

Linearize a nonlinear function using piecewise linear approximation

Find below some approaches to linearize the cubic function y =e= x*sqr(x) - 7*sqr(x) + 14*x - 8 using piecewise linear approximation. In general, piecewise linear functions can be modeled using binary variables, SOS1 type formulations or SOS2 type formulations. Check textbooks like Nemhauser and Wol...
by aileen
2 years ago
Forum: GAMS-FAQ
Topic: GAMS Related References
Replies: 0
Views: 5834

GAMS Related References

This post contains a list of some GAMS related scientific papers. Please email suggestions for additions to this list to support@gams.com. Johannes Bisschop and Alexander Meeraus. On the Development of a General Algebraic Modeling System in a Strategic Planning Environment. In Applications, volume 2...