help please why ??
显示 更早的评论
A = [ 1 3 2 6 ; 5 7 7 0 ; -2 6 -2 1 ] ;
j = sum(A(1))
j= 1 why ???
采纳的回答
Jim Riggs
2018-2-28
the statement
sum(A(1))
is summing only the first element in A, which is 1.
If you want to sum the first row, it should be
sum(A(1,:))
and if you want to sum the first column, it is
sum (A(:,1))
3 个评论
ahmad qadan
2018-2-28
Jim Riggs
2018-2-28
The matrix A is:
1 3 2 6
5 7 7 0
-2 6 -2 1
The first element in A is A(1) which is 1. So the statement
sum(A(1))
is the same as
sum(1)
and has a value of 1.
ahmad qadan
2018-2-28
更多回答（1 个）
elham kreem
2018-2-28
1 个投票
WHAT are you want? IF YOU want to sum all the values then use Sum (A) BUt you sum the first element only. IF you help this answer then except to it.
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