如何获得应用于方程的用户输入(作为一个数字)

Question

我试图编程一个场景，用户将输入两条信息，一个6分钟的步行距离，米在基线(6 two基线)，然后6分钟步行距离米在24周(6 two 24周)。我希望用户提供这些信息，而不是我在程序中断言它们。输入这些数字后，它们需要应用于方程：(6 MWD24周-6 MWD基线)=x，然后应用到这个等式:X/6MWD基线=y，如果y >/= 0.2，则程序将表示成功。如果y在0.05-0.19之间，则表示临床改善。如果y <0.049，则程序将表示失败。

我在脚本测试的早期就遇到了一个错误，甚至在我试图对我的“临床改进”或“失败”行进行编程之前，我的用户输入的6 MWD基线和6MWD24周预期是整数或浮动。对我可能做错了什么有什么指导吗？

CLIPS> (clear)
CLIPS> (defrule MAIN::6WMDbaseline-check
    =>
    (printout t "What is the distance on the baseline 6-minute walk distance in meters?" crlf)
    (assert (6MWDbaseline (read))))
CLIPS> (defrule MAIN::6MWD24week-check
    =>
    (printout t "What is the distance on the 24-week 6-minute walk distance in meters?" crlf)
    (assert (6MWD24week (read))))
CLIPS> (defrule MAIN::success-decision
    (6MWDbaseline ?6MWDbaseline)
    (6MWD24week ?6MWD24week)
    =>
    (if (- 6MWD24week 6MWDbaseline = x) and (/ x 6MWDbaseline >0.2))
    then
    (printout t "Primary outcome met, greater than 20% improvement in 6-minute walk distance" crlf))
[ARGACCES2] Function '-' expected argument #1 to be of type integer or float.

ERROR:
    (defrule MAIN::success-decision
    (6MWDbaseline ? 6MWDbaseline)
    (6MWD24week ? 6MWD24week)
    =>
    (if (- 6MWD24week 6MWDbaseline = x)
CLIPS> 

谢谢您的帮助！玛妮

Answer 1

使用绑定函数将值赋给规则操作中的变量。此外，变量名必须以字母开头。

         CLIPS (6.4 2/9/21)
CLIPS> 
(defrule 6WMDbaseline-check
    =>
    (printout t "What is the distance on the baseline 6-minute walk distance in meters?" crlf)
    (assert (6MWDbaseline (read))))
CLIPS> 
(defrule 6MWD24week-check
    =>
    (printout t "What is the distance on the 24-week 6-minute walk distance in meters?" crlf)
    (assert (6MWD24week (read))))
CLIPS> 
(defrule success-decision
    (6MWDbaseline ?baseline)
    (6MWD24week ?week24)
    =>
    (bind ?x (- ?week24 ?baseline))
    (bind ?y (/ ?x ?baseline))
    (switch TRUE
       (case (> ?y 0.2)
             then
             (printout t "Primary outcome met, greater than 20% improvement in 6-minute walk distance" crlf))
       (case (and (>= ?y 0.05) (<= ?y 0.2))
             then
             (printout t "Primary outcome improved, between 5% and 20% improvement in 6-minute walk distance" crlf))
       (case (< ?y 0.05)
             then
             (printout t "Primary outcome failed, less than 5% improvement in 6-minute walk distance" crlf))))
CLIPS> (reset)
CLIPS> (run)
What is the distance on the baseline 6-minute walk distance in meters?
100
What is the distance on the 24-week 6-minute walk distance in meters?
121
Primary outcome met, greater than 20% improvement in 6-minute walk distance
CLIPS> (reset)
CLIPS> (run)
What is the distance on the baseline 6-minute walk distance in meters?
100
What is the distance on the 24-week 6-minute walk distance in meters?
115
Primary outcome improved, between 5% and 20% improvement in 6-minute walk distance
CLIPS> (reset)
CLIPS> (run)
What is the distance on the baseline 6-minute walk distance in meters?
100
What is the distance on the 24-week 6-minute walk distance in meters?
104
Primary outcome failed, less than 5% improvement in 6-minute walk distance
CLIPS>