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HP 50g - summation - Simone Cerica - 06-03-2016 12:47 PM
Hello everyone, is there a way to make a summation in such a way that
'\GS(N=1,5,XN)' = 'X1+X2+X3+X4+X5' ?
Simone
RE: HP 50g - summation - wojtek - 06-03-2016 03:36 PM
(06-03-2016 12:47 PM)Simone Cerica Wrote: Hello everyone, is there a way to make a summation in such a way that
'\GS(N=1,5,XN)' = 'X1+X2+X3+X4+X5' ?
Simone
Your post is not clear enough, but if you want 50g build an expression 'X1+X2+X3+X4+X5' instead of counting the sum, I'm afraid there is no such a function buit in, but it should be easy to write a program using the concatenation of strings, that is "+".
RE: HP 50g - summation - Tugdual - 06-03-2016 04:21 PM
Or is that the sum,of a list?
RE: HP 50g - summation - Claudio L. - 06-03-2016 05:20 PM
(06-03-2016 12:47 PM)Simone Cerica Wrote: Hello everyone, is there a way to make a summation in such a way that
'\GS(N=1,5,XN)' = 'X1+X2+X3+X4+X5' ?
Simone
How about this way?
Code:
<< -> N V
<< 1 N FOR K
'V' RCL
->STR TAIL HEAD K + STR->
NEXT
WHILE N 1 > REPEAT
+ 'N' DECR DROP
END
>>
>>Store it in let's say XSUM, then:
'XSUM(5,X)' EVAL will produce what you want. It's limited to single-letter identifiers (by using TAIL HEAD, this can be improved).
Another improvement could be a start value for N, but you get the idea.
Quick footnote: For those trying this in newRPL, the TAIL HEAD combination needs to be removed, as the identifiers in symbolics are unquoted, then the code is good for arbitrary length identifiers.
RE: HP 50g - summation - Simone Cerica - 06-04-2016 09:26 AM
(06-03-2016 05:20 PM)Claudio L. Wrote: 'XSUM(5,X)' EVAL will produce what you want. It's limited to single-letter identifiers (by using TAIL HEAD, this can be improved).
Another improvement could be a start value for N, but you get the idea.
It was just what I wanted,
grazie Claudio.
