APPENDIX B 



ERROR MESSAGES AND DIAGNOSTICS 



The main program in NETVSL calls many subprograms to accomplish particular phases 

 of the calculations. After the calls to most of the subprograms, the main program 

 tests the status of the variable: lERROR. If lERROR is nonzero, this error message is 

 printed in which xxxxx, yyyyy, and zzzzz are replaced by the values of lERROR, JERROR, 

 and KERROR, respectively: 



ERROR xxxxx HAS OCCURRED IN SECTION yyyyy. ERROR COUNT - zzzzz. 



The value of KERROR is incremented by one each time an error condition is encoun- 

 tered, and the tree is omitted from further processing. 



The values of lERROR and their associated diagnostics are grouped by the sub- 

 programs in which they arise in the following list. 



Subprogram 

 DIALEN 



lERROR 



401 



Interpretation 



Number of sections is greater than the 40 

 storage locations provided. If this is true, 

 the program dimensions must be increased. 

 Otherwise, look for such situations as 

 duplicated tree numbers in successive trees, 

 or missing asterisks on dendrometer cards. 



402 



Number of forks is greater than the eight 

 storage locations provided. If this is true, 

 the program dimensions must be increased, or 

 the tree pruned. 



403 



Number of forks as indicated by the occurrence 

 of fork codes does not match the number of 

 tops indicated by zero diameters. Check for 

 missing fork codes or extraneous zero diame- 

 ters . 



404 



Negative diameter found. Check data for cause, 



Each of the above errors will cause DEBUG output to be printed. 



BOARDF 



801 



See DIALEN 401 above, 



802 



Indexes are in error in calculating the 

 positions of saw-log tops. If there are no 

 previous errors for this tree, obtain DEBUG 

 output and consult with the senior author. 



CUAREA 



1101 



An error has occurred in matching the cull 

 codes of the data with the cull code keys 

 stored in BLOCK DATA. This matching is 

 accomplished in CULVOL. Check that NCODE has 

 not been initialized to a value greater than 

 10 in BLOCK DATA. 



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