The Expression Node
表达式节点
The Expression Node is found on the Programming>>Numeric palette (see Figure 6.73) and is basically just a simplified Formula Node having just one unnamed input and one unnamed output.
Expression Node-表达式节点在Programming>>Numeric模板中(见图6.73), 岸基本上它就是一个简化了的公式节点, 只不过它只有一个未命名的输入端口和一个未命名的输出端口.
Figure 6.73. Expression Node shown on the block diagram (left) and on the Programming>>Numeric palette (right)
图6.73. 表达式节点显示框图中(左)和在Programming>>Numeric模板中(右)
Figure 6.73 shows the Expression Node with annotated parts. Unlike the Formula Node, you do not have to name the input or output terminals. (Because there is only one input and one output, there is no ambiguity.) Also, because there is only one expression, there is no need for a semicolon at the end of the expression. (The Formula Node does require semicolons at the end of each expression.) Finally, in an Expression Node, you can use any valid name you want for the input variable (in our previous example, "x" could have just as easily been "y" or "Tps" with the same effect), but remember you can only use one variable in an Expression Node, unlike the Formula Node, which allows multiple input and output variables.
图6.73显示了带注解的表达式节点. 不同于公式节点, 你无需命名表达式节点的输入输出端子.(因为只有一个输入端和一个输出端, 不会造成混淆) 并且, 因为这儿只有一个表达式, 所以也无需在表达式结尾加冒号. (公式节点必须在每个表达式的结尾加冒号). 最后, 在一个表示式节点中, 你能够使用任何有效的名字给输入变量命名(在我们前面的例子中, “x”也可以简单地换成”y”或者”Tps”而效果是同样的, 但是记住你在表达式节点中只能使用一个变量, 不同于公式节点, 在公式节点中允许多个输入和输出变量.
The same operators and syntax of the Formula Node apply to the Expression Node.
公式节点中的运算符和语法同样适用与表达式节点.
