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<div class="moz-cite-prefix">Le 11/02/2020 à 02:37, Federico Miyara
a écrit :<br>
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<blockquote type="cite"
cite="mid:4ecf33be-890c-3a5d-0e0f-33602448a319@fceia.unr.edu.ar">
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<font face="Courier New">Thanks, Samuel.<br>
<br>
This certainly clarifies how [] behaves. But is there a
rationale for sum([])==0 and yet cumsum([])==[]?<br>
</font></blockquote>
<p>For sum([])==0 : <br>
IMO this is OK. Personnaly, i expect from<br>
sum(A) + sum(B) + .. sum(Z) not to be killed just because one of
the arguments is []. So, to me, this case is somewhat distinct
from the A +[]. A + [] works element-wise.<br>
Because a vector is expected from <tt>sum([],"r")</tt>, that then
would be added in an element-wise way, <br>
<font size="-1"><tt>--> sum([],"r")</tt><tt><br>
</tt><tt> ans =</tt><tt><br>
</tt><tt> []</tt></font><tt><br>
</tt>is also OK.</p>
<p>I would give the same rationale for prod([])==1.<font
face="Courier New"><br>
</font><br>
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<blockquote type="cite"
cite="mid:4ecf33be-890c-3a5d-0e0f-33602448a319@fceia.unr.edu.ar"><font
face="Courier New"> By the way, it would be useful to include
cumsum and cumprod among the examples,</font></blockquote>
<p>Right<br>
<br>
Regards<br>
Samuel<br>
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