IfcTable
实体定义
IfcTable是用于以行和列的形式提供信息的数据结构。每个实例可以有IfcTableColumn实例,用于定义每个列的名称、描述和单位。信息行存储为IfcTableRow对象列表。
限制:为了向后兼容,IfcTable对象的行被约束为具有相同数量的单元格。表格的第一行提供了单元格的数量。所有其他行都必须包含相同数量的单元格。这由WR2执行。
下图说明了表格的使用。
下图描述了IFC4之前表格的结构。
IFC1.5中的新实体。
IFC4 添加了列属性。
Formal Propositions
Rule | Description |
---|---|
WR1 | Ensures that each row defines the same number of cells. The rule compares whether all other rows of the IfcTable have the same number of cells as the first row. |
WR2 | The rule restricts the allowed number of heading rows to no more than one. |
Attribute inheritance
# | Attribute | Type | Cardinality | Description | C |
---|---|---|---|---|---|
IfcTable | |||||
1 | Name | IfcLabel | [0:1] | X | |
2 | Rows | IfcTableRow | L[1:?] | Reference to information content of rows. | X |
3 | Columns | IfcTableColumn | L[1:?] | The column information associated with this table. | X |
NumberOfCellsInRow :=HIINDEX(Rows[1].RowCells) |
IfcInteger | [1:1] | The number of cells in each row, this complies to the number of columns in a table. See WR2 that ensures that each row has the same number of cells. The actual value is derived from the first member of the Rows list. | X | |
NumberOfHeadings :=SIZEOF(QUERY( Temp <* Rows | Temp.IsHeading)) |
IfcInteger | [1:1] | The number of headings in a table. This is restricted by WR3 to max. one. | X | |
NumberOfDataRows :=SIZEOF(QUERY( Temp <* Rows | NOT(Temp.IsHeading))) |
IfcInteger | [1:1] | The number of rows in a table that contains data, i.e. total number of rows minus number of heading rows in table. | X |
EXPRESS Specification
ENTITY IfcTable; Name : OPTIONAL IfcLabel; Rows : OPTIONAL LIST [1:?] OF IfcTableRow; Columns : OPTIONAL LIST [1:?] OF IfcTableColumn; DERIVE NumberOfCellsInRow : IfcInteger := HIINDEX(Rows[1].RowCells); NumberOfHeadings : IfcInteger := SIZEOF(QUERY( Temp <* Rows | Temp.IsHeading)); NumberOfDataRows : IfcInteger := SIZEOF(QUERY( Temp <* Rows | NOT(Temp.IsHeading))); WHERE WR1 : SIZEOF(QUERY( Temp <* Rows | HIINDEX(Temp.RowCells) <> HIINDEX(Rows[1].RowCells))) = 0; WR2 : { 0 <=
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标签:rows,IfcTable,number,Rows,IfcInteger,table From: https://www.cnblogs.com/herd/p/16990657.html