How to write a condition ?

Hi, i have to write this condition in my code but i don't know how
moyenne <= '(-inf-6.95]'

1 Comment

Jan
Jan on 23 May 2017
Are you aware that the notation, you have invented, is not clear or unique? What exactly does the smaller than operator do with a string? What exactly is (-inf-6.95] ?
Do you mean: Moyenne is > -Inf and small or equal -6.95?

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Answers (2)

dpb
dpb on 23 May 2017
Edited: dpb on 24 May 2017
Can't. Comparison operations always return logical 0 (false) where A or B have NaN elements.
Best you can do is test if result isfinite or not. See
doc isfinite % and friends for more information
ADDENDUM
OK, w/ the additional background try
Ayup...
moyenne<=-6.95
would give everything <= the breakpoint into that region, up to as large a negative value as can be represented. If the model can/does generate -Inf, that will have to be special-cased.
Jan's guess wasn't too far off, looks like
if sign(moyenne)*isinf(moyenne)==-1 | moyenne<=-6.95 % handle -Inf, too...
should do it. The first tests for -Inf and the other takes the case is finite but < than the breakpoint.
Do the similar thing on an unbounded upper bin as well.
Jan
Jan on 23 May 2017
A bold guess:
isfinite(moyenne) & moyenne <= -6.95

9 Comments

afef
afef on 23 May 2017
i mean moyenne is smaller or equal to the interval from minis infinite to 6.95
???
dpb
dpb on 23 May 2017
If it is finite it's smaller; the interval including -Inf is, well, "infinite", at least to the best representation can make digitally.
As noted above, you can't do anything with Inf computationally other that test whether a value is/is not finite. As soon as you bring Inf into any construct, the result is another Inf or perhaps NaN which is of no real benefit either.
Jan
Jan on 23 May 2017
@afef: What does "smaller or equal to an interval" mean? What is the contents of "moyenne"? Is it a scalar number or two numbers to repesent an interval? You still let us guess, what you want to achieve. Please explain it in a clear sentence: "Moyenne has [e.g.] the value [...] and I want to get the result [true/false] it is [larger than -Inf and smaller than -6.95]".
I have suggested some code. Did you try it? Does it work? If not, what is the difference between the result and what you want?
dpb
dpb on 23 May 2017
"moyenne is smaller or equal to the interval from minis infinite to 6.95"
Is this a cumulative distribution function or the like, mayhaps???
Tell us what the context is and maybe we can figure out something...as a standalone, it's likely what you've gotten is best can do...
afef
afef on 24 May 2017
actually i used the AntMiner+ algorithm for classification and it give me a decision list that i used in my code to test this given rule . Also this algorithm does not handle numeric values so they will be descritized so this is why i get this interval
dpb
dpb on 24 May 2017
Then it's simply binning and everything <-6.95 goes to the first bin; you don't need to describe the lower limit at all.
afef
afef on 24 May 2017
Edited: afef on 24 May 2017
Ok so i should just put moyenne <= 6.95 ?
dpb
dpb on 24 May 2017
Edited: dpb on 24 May 2017
Yeah; expanded answer above based on comment...

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on 23 May 2017

Edited:

dpb
on 24 May 2017

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