How can I add the elements in the sublists?
For example, if I have the list which is
m={{1,3},{2,3},{4,1}} then, the output that I want is 3+3+1=10. How can I do this?
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8 
5 Answers
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3 I thinks the cleanest way is:
Total@m[[All, 2]] using Esc[[Esc and Esc]]Esc.
If you use it a lot (like me), you can create shortcuts as explained here.
- $\begingroup$ You can use these shortcuts if you don't like pressing
Escevery time forPartbrackets $\endgroup$2012-10-30 14:27:59 +00:00Commented Oct 30, 2012 at 14:27 - $\begingroup$ Yes, I use it. I put in the post. Tks $\endgroup$Murta– Murta2012-10-30 18:46:39 +00:00Commented Oct 30, 2012 at 18:46
- $\begingroup$ @Murta, I asked the Q on [[ ]] but find all the answers a pain. Can you make a palette button or single front-end command? $\endgroup$alancalvitti– alancalvitti2015-11-13 17:29:14 +00:00Commented Nov 13, 2015 at 17:29
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1 Following @b.gatessucks
Total[m[[;; , 2]]] (* 7 *) If you want to sum all components (as @image_doctor pointed out too, sorry I missed that)
Plus @@@ Transpose[m] (* 7 7 *) 
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Total[m[[All , 2]]]works as well. :) $\endgroup$J. M.'s missing motivation– J. M.'s missing motivation2012-10-30 12:05:58 +00:00Commented Oct 30, 2012 at 12:05
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Last@Total[{{1, 3}, {2, 3}, {4, 1}}] or
Total[{{1, 3}, {2, 3}, {4, 1}}] for both components
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1 {{1, 3}, {2, 3}, {4, 1}} // Query[Total, 2] 7
Unfortunately the current Query and associated Dataset implementation is riddled with workarounds - this is going to tech support >>
{{1, 3}, {2, 3}, {4, 1}} // Query[Total, 2] // Trace // LeafCount 3175
Anyone interested in a timing study?
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{{1, 3}, {2, 3}, {4, 1}} // Query[Total, 2] // Trace // LeafCountresults in697as of May 2023. $\endgroup$Syed– Syed2023-05-12 07:30:11 +00:00Commented May 12, 2023 at 7:30
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Just For fun.
m = {{1, 3}, {2, 3}, {4, 1}}; Last[Total[m]] 
Partto get the elements from the list, thenTotalto sum them up. $\endgroup$Plus @@@ (m\[Transpose])will give you a list of the sums of the various elements of your list. $\endgroup$