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help sum
SUM Sum of elements.
S = SUM(X) is the sum of the elements of the vector X. If X is a matrix,
S is a row vector with the sum over each column. For N-D arrays,
SUM(X) operates along the first non-singleton dimension.
S = SUM(X,'all') sums all elements of X.
S = SUM(X,DIM) sums along the dimension DIM.
S = SUM(X,VECDIM) operates on the dimensions specified in the vector
VECDIM. For example, SUM(X,[1 2]) operates on the elements contained in
the first and second dimensions of X.
S = SUM(...,OUTTYPE) specifies the type in which the
sum is performed, and the type of S. Available options are:
'double' - S has class double for any input X
'native' - S has the same class as X
'default' - If X is floating point, that is double or single,
S has the same class as X. If X is not floating point,
S has class double.
S = SUM(...,NANFLAG) specifies how NaN (Not-A-Number) values are
treated. The default is 'includenan':
'includenan' - the sum of a vector containing NaN values is also NaN.
'omitnan' - the sum of a vector containing NaN values
is the sum of all its non-NaN elements. If all
elements are NaN, the result is 0.
Examples:
X = [0 1 2; 3 4 5]
sum(X, 1)
sum(X, 2)
X = int8(1:20)
sum(X) % returns double(210), accumulates in double
sum(X,'native') % returns int8(127), because it accumulates in
% int8 but overflows and saturates.
See also PROD, CUMSUM, DIFF, ACCUMARRAY, ISFLOAT.
Documentation for sum
doc sum
Other uses of sum
codistributed/sum fixedpoint/sum tall/sum
dlarray/sum gpuArray/sum timeseries/sum
duration/sum sym/sum
Then spend some time on the MATLAB Onramp tutorial, since this is a basic question.
