lipsolWIN32.zip_Linear programming

function err=errcheck(str, flag) global v lv rv vn_vars err = 0; check_obj = 1; check_cons = 2; check_bounds = 3; if (isempty(str)) err = 1; return; end tmpstr = str(find(str ~= ' ' & str ~= 0)); operator = find(tmpstr == '=' | tmpstr == '>' | tmpstr == '<' ); if (~isempty(operator)) if (operator(1) == 1 | operator(length(operator)) == length(tmpstr)) err = errmessage('Input incomplete'); return; end end operator = find(tmpstr == '+' | tmpstr == '-' ); if (~isempty(operator)) if ( operator(length(operator)) == length(tmpstr)) err = errmessage('Input incomplete'); return; end end % coefficient check ...... lbrace = find(str == '{'); rbrace = find(str == '}'); len = length(lbrace); if ( len ~= length(rbrace) ) errmessage('Braces unmatched'); return; end if (len ~= 0) tmpstr =['+' tmpstr 'z']; tmplbrace = find(tmpstr == '{'); tmprbrace = find(tmpstr == '}') ; patt = []; for i = 1:len if (~isletter(tmpstr(tmprbrace(i)+1)) &... isempty(findstr(tmpstr(tmprbrace(i)+1),'+-<>='))) |... isempty(findstr(tmpstr(tmplbrace(i)-1),'+-<>=')) errstr = 'A coefficient must be a number or an expression in "{}"'; err = errmessage(errstr); return; end if (rbrace(i)-lbrace(i) <2) errmessage('Empty {}'); return; end inner = lbrace(i):rbrace(i); patt = [patt inner]; lbracket = find(str(inner) == '('); rbracket = find(str(inner) == ')'); if (length(lbracket) ~= length(rbracket)) err = errmessage(' "(" dose not match ")" '); return; end end str(patt) = []; end % general checking ...... error = ~( ... str == '+' | str == '-' | str == '.' | str == ' ' ... | str == 0 | str == '=' | str == '<' | str == '>' ... | (str >= '0' & str <= '9') | isletter(str)); if any(error) errstr = str(find(error)); err = errmessage(['Illegal charactor(s): ' errstr]); return; end operator = (find(str == '+' | str == '-' )); len = length(operator); if (len > 1) error = any(operator(2:len) - operator(1:len-1) == 1); if any(error) err = errmessage('Successive operators not allowed'); return; end end % objective check ...... if (flag == check_obj) error = (str == '=' | str == '>' | str == '<'); if any(error) err = errmessage('"=", "<" or ">" not allowed in objective'); return; end nonblank = find(str ~= ' '); s3 = lower(str(nonblank(1):nonblank(1)+2)); if any(s3 ~= 'max') & any(s3 ~= 'min') err = errmessage('Max or min must appear first in objective'); return; else str=str(nonblank(1)+3:length(str)); end end % constraints checking ...... if (flag == check_cons) operator = find(str == '=' | str == '>' | str == '<'); if (length(operator) ~= 1) err = errmessage('Use one and only one of "=", "<" or ">"'); return; end end % bounds checking ...... if (flag == check_bounds) if (~isempty(find(str == '='))) err = errmessage('NO "=" allowed in bounds'); return; end operator = find(str == '>' | str == '<' ); len_op = length(find(str == '>' | str == '<' )); if (len_op < 1 | len_op > 2) err = errmessage('There must be 1 or 2 inequalities in a bound'); return; elseif (len_op == 2) gt = length(find(str == '>')); lt = length(find(str == '<')); if (~(gt == 2 | lt == 2)) err = errmessage('Misused ">" or "<"'); return; end end interval = [0 operator length(str)+1]; for i = 1:length(interval)-1 substr = str(interval(i)+1:interval(i+1)-1); if (isempty(substr)) substr = '9'; end substr = substr(find(substr ~= ' ')); subletter = find((substr >= 'A' & substr <= 'Z') | ... (substr >= 'a' & substr <= 'z') ); if(~isempty(substr)) subop = find(substr =='+' | substr =='-' | substr =='*'); else subop = []; end if (~isempty(subletter)) if (subletter(1) ~= 1) err = errmessage('Coefficients on variables not allowed'); return; end if (~isempty(subop)) err = errmessage('Arithmatic operators on variables not allowed'); return; end end end letter = find((str >= 'A' & str <= 'Z') | (str >= 'a' & str <= 'z')); len_letter = length(letter); if (len_letter == 0) err = errmessage('No variable'); return; end error = (letter(1) < operator(1) & letter(len_letter) > operator(1)) ... | (letter(1) < operator(len_op) & ... letter(len_letter) > operator(len_op)) ... | (len_op == 2 & letter(1) < operator(1)) ... | (len_op == 2 & letter(len_letter) > operator(len_op)); if any(error) err = errmessage('Illegal expression in bounds'); return; end end % blank space check ...... nonblank = str ~= ' '; slen = length(nonblank); nonblank = [nonblank 1]; for i = 1:slen if (nonblank(i) == 0 & nonblank(i+1) == 1) nonblank(i) = 1 ; end end nonblank = nonblank(1:slen); str = str(find(nonblank == 1)); str = ['@' str '@']; blank = find(str == ' '); if (~isempty(blank)) b_blank = str(blank -1); a_blank = str(blank +1); error = ( (b_blank >= '0' & b_blank <= '9') & ... (a_blank >= '0' & a_blank <= '9') ) ... | ( isletter(b_blank) & isletter(a_blank) ) ... | ( isletter(b_blank) & (a_blank >= '0' & a_blank <= '9') ); if any(error) err = errmessage('Space in wrong place'); return; end end