求问CHKTRE(ICODE)这个函数

ycjwanok

这边要用到 但看不明白 问问各位  CHKTRE(ICODE)函数是什么作用的？ 返回值个表示什么意思？
# Z+ a- j0 @( P$ Z$ B手册里给的解释如下
: Z. W$ L  u$ P; LCALL CHKTRE(ICODE)
4 c% h) Y+ i1 _' [9 uIf the case contains Type 4 (or greater) buses with in-service branches then an error condition is
: k, `% [+ l0 w# Z6 j  Hreturned. Counts number of islands not containing a Type 3 (swing) bus. It may be inappropriate to
* B' Q# S7 I# U* Lcall this subroutine with generators converted; since there will be no Type 3 buses, it will simply
count every island (finding at least one unless there is no working case).
ICODE Error code (integer output):
0 No errors.
-1 No in-service buses remaining.
-2 There are Type 4 buses with in-service branches connected.
8 D: X& u0 ~1 x8 a* u>0 Number of islands without a Type 3 bus.
- {) A% p, @; u4 D太谢谢了