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Re: NaN2: Another NaN, an NaN alternative, two types of NaN?
Posted:
Mar 12, 2009 5:04 AM
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"Roger Stafford" <ellieandrogerxyzzy@mindspring.com.invalid> wrote in message <gpah4d$183$1@fred.mathworks.com>...
> "Roger Stafford" <ellieandrogerxyzzy@mindspring.com.invalid> wrote in message <gpagqo$b9e$1@fred.mathworks.com>...
> > ......
> > ...... However, you do have the problem of recognizing the difference afterwards. At the moment I cannot think of a way to do it.
> > ......
>
> ... except of course by using 'format hex'.
>
> Roger Stafford
Practical implementation of Roger's remark
% function to generate an NaN of specific type 1, 2, ..., 255
nant = @(type) typecast(uint8([type 0 0 0 0 0 248 255]),'double');
% Function which get the type, 0 if Matlab double or NaN
gettype = @(x) isnan(x).*double(subsref(typecast(x,'uint8'), ...
substruct('()',{1})));
x1 = nant(1)
x2 = nant(2)
gettype(x1)
gettype(x2)
Bruno
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