Lets say I have this range of numbers, I want to expand these intervals. What is going wrong with my code here? The answer I am getting isn't correct :(
intervals are only represented with - each 'thing' is separated by ;
I would like the output to be: -6 -3 -2 -1 3 4 5 7 8 9 10 11 14 15 17 18 19 20
range_expansion('-6;-3--1;3-5;7-11;14;15;17-20 ')
function L=range_expansion(S)
% Range expansion
if nargin < 1;
S='[]';
end
if all(isnumeric(S) | (S=='-') | (S==',') | isspace(S))
error 'invalid input';
end
ixr = find(isnumeric(S(1:end-1)) & S(2:end) == '-') 1;
S(ixr)=':';
S=['[',S,']'];
L=eval(S) ;
end
ans =
-6 -2 -2 -4 14 15 -3
CodePudding user response:
You can use regexprep
to replace ;
by ,
and the -
that define ranges by :
. Those -
are identified by them being preceded by a digit. The result is a string that can be transformed into the desired output using str2num
. However, since this function evaluates the string, for safety it is first checked that the string only contains the allowed characters:
in = '-6;-3--1;3-5;7-11;14;15;17-20 '; % example
assert(all(ismember(in, '0123456789 ,;-')), 'Characters not allowed') % safety check
out = str2num(regexprep(in, {'(?<=\d)-' ';'}, {':' ','})); % replace and evaluate