ProcessBlock is used to simplify inheritance of Pyomo's Block. The code below provides an example of how a new ProcessBlock class can be implemented. The new ProcessBlock class has a ConfigBlock that allows each element of the block to be passed configuration options that affect how a block is built. ProcessBlocks have a rule set by default that calls the build method of the contained ProcessBlockData class.
from pyomo.environ import * from pyomo.common.config import ConfigValue from idaes.core import ProcessBlockData, declare_process_block_class
@declare_process_block_class("MyBlock") class MyBlockData(ProcessBlockData): CONFIG = ProcessBlockData.CONFIG() CONFIG.declare("xinit", ConfigValue(default=1001, domain=float)) CONFIG.declare("yinit", ConfigValue(default=1002, domain=float)) def build(self): super(MyBlockData, self).build() self.x = Var(initialize=self.config.xinit) self.y = Var(initialize=self.config.yinit)
The following example demonstrates creating a scalar instance of the new class. The default key word argument is used to pass information on the the MyBlockData ConfigBlock.
m = ConcreteModel() m.b = MyBlock(default={"xinit":1, "yinit":2})
The next example creates an indexed MyBlock instance. In this case, each block is configured the same, using the default argument.
m = ConcreteModel() m.b = MyBlock([0,1,2,3,4], default={"xinit":1, "yinit":2})
The next example uses the initialize argument to override the configuration of the first block. Initialize is a dictionary of dictionaries where the key of the top level dictionary is the block index and the second level dictionary is arguments for the config block.
m = ConcreteModel() m.b = MyBlock([0,1,2,3,4], default={"xinit":1, "yinit":2}, initialize={0:{"xinit":1, "yinit":2}})
The next example shows a more complicated configuration where there are three configurations, one for the first block, one for the last block, and one for the interior blocks. This is accomplished by providing the idx_map argument to MyBlock, which is a function that maps a block index to a index in the initialize dictionary. In this case 0 is mapped to 0, 4 is mapped to 4, and all elements between 0 and 4 are mapped to 1. A lambda function is used to convert the block index to the correct index in initialize.
m = ConcreteModel() m.b = MyBlock( [0,1,2,3,4], idx_map = lambda i: 1 if i > 0 and i < 4 else i, initialize={0:{"xinit":2001, "yinit":2002}, 1:{"xinit":5001, "yinit":5002}, 4:{"xinit":7001, "yinit":7002}})
The core part of any IDAES Block is the build method, which contains the instructions on how to construct the variables, constraints and other components that make up the model. The build method serves as the default rule for constructing an instance of an IDAES Block, and is triggered automatically whenever an instance of an IDAES Block is created unless a custom rule is provided by the user.
idaes.core.process_block
declare_process_block_class
ProcessBlock
idaes.core.process_base
ProcessBlockData