MATLAB: Switch case option valid for two cases

switch case

Hi, there.
Thanks in advance for any help!
I'm trying to extract P and/or S wave velocity profiles from corresponding text files. Here is what I'm trying. It doesn't seem to like that 'ps' is being called for both cases.
I know I could just copy the separate 'p' and 's' case options into a third 'ps' option, but I was hoping there was a way to not do that. 
n = input('Which velocity model(s)? Enter p, s, or ps in single quotes: ');
switch n
    case {'p','ps'}
        % code to extract P velocity from P velocity text file
    case {'s','ps'}
        % code to extract S velocity from S velocity text file
    otherwise
        warning('Invalid choice')
end

Best Answer

But, presuming 'ps' means to do both 'p' and 's', you need that case as well as written anyway because in Matlab the switch block case statements do NOT "fall through" as in C.
opt=input('Which velocity model(s)? Enter p, s, or ps: ','s');  % return string
if contains(opt,'p')
  % code to extract P velocity from P velocity text file
end
if contains(opt,'s')
  % code to extract S velocity from S velocity text file
end
does either or both and is also insensitive to your user entering 'sp' instead of 'ps'. Of course, it will also do both if user enters 'stop' so should probably do some input verification as well.
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