boundary condition from a table

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Author Message   shohel mahmud (smahmud) Member Username: smahmud Post Number: 6 Registered: 09-2003 Posted on Friday, July 02, 2004 - 04:36 pm:    Hi there suppose in a "value( )" boundary condition I have to use some values that cannot be generated by any analytic function. But "table" is ok. How can I use a table to define boundary condition. As a simple example I attached a *.pde file solving heat conduction equation in a square slab. top and bottom walls are adiabatic (natural(H)=0), where H is temperature. left wall is isothermal (value(H)=0). but at right wall I have use a table to define specific values. I also attached a simple table file showing all of the value equal to 2. Please help me. Shohel heat.pde (0.7 k) table1.tbl (0.1 k)   Robert G. Nelson (rgnelson) Moderator Username: rgnelson Post Number: 176 Registered: 06-2003 Posted on Friday, July 02, 2004 - 05:39 pm:    You have a table with five "x" values, all equal to 1. This causes a blowup, because the interpolator must divide by the table interval, which in your case is zero. You can fix this in either of two ways: 1) give distinct values for the x-coordinates. It does no damage if a table extends beyond the area you intend to use it in. 2) create a one-dimensional table using only "y" as a coordinate. A TABLE file does not need to use the spatial coordinates of the domain as its coordinates. You can build a one-, two- or three-dimensional table with anything you want as the independent variables. The name declared in the table file merely needs to coincide with some known name in the script file which reads it. Or, you can override the table file name in the TABLE input statement. See "Table Input" in the Help Index.   Lu Chi (chi) New member Username: chi Post Number: 1 Registered: 02-2005 Posted on Monday, February 21, 2005 - 09:56 am:    I made a table to upload the boundary conditions to my cilindrical model. The table is in the form: Z 2 0,1 0,2 R 2 0,5 1 data 2 3 2 3 Why the program returns me an error as "Bad table item"? Thanks   Robert G. Nelson (rgnelson) Moderator Username: rgnelson Post Number: 327 Registered: 06-2003 Posted on Monday, February 21, 2005 - 03:37 pm:    FlexPDE uses the US custom of '.' for decimal separator, not ','.