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In Julia are there no built in functions to sum an array of numbers?
x = rand(10)
sum(x) # or sum(x, 1)
ERROR: MethodError: objects of type Float64 are not callable
I mean I could write a for loop to sum it as follows,
sum = 0.0
for i in 1:length(x)
sum += x[i]
end
but it just surprises me if julia don't have this built in somewhere?
824
S = sum( A ) returns the sum of the elements of A along the first array dimension whose size does not equal 1. If A is a vector, then sum(A) returns the sum of the elements. If A is a matrix, then sum(A) returns a row vector containing the sum of each column.
Using findall() method The findall() method is used to find all the occurrences of the required element from an array, and return an Array (or CartesianArray, depending on the dimensions of input array) of the index, where the elements are present in the input array.
A Vector in Julia can be created with the use of a pre-defined keyword Vector() or by simply writing Vector elements within square brackets([]). There are different ways of creating Vector. vector_name = [value1, value2, value3,..] or vector_name = Vector{Datatype}([value1, value2, value3,..])
As @Michael K. Borregaard mentions, you reasigned the variable sum (exported by default from Base) with the value of a Float64 at some point. When you restated your session, sum was again the Base.sum default, ie:
julia> x = rand(10)
10-element Array{Float64,1}:
0.661477
0.275701
0.799444
0.997623
0.731693
0.557694
0.833434
0.90498
0.589537
0.382349
julia> sum
sum (generic function with 16 methods)
julia> sum(x)
6.733930084133119
julia> @which sum(x)
sum(a) in Base at reduce.jl:359
Notice the warning:
julia> original_sum = sum
sum (generic function with 16 methods)
julia> sum = x[1]
WARNING: imported binding for sum overwritten in module Main
0.6614772171381087
julia> sum(x)
ERROR: MethodError: objects of type Float64 are not callable
julia> sum = original_sum
sum (generic function with 16 methods)
julia> sum(x)
6.733930084133119
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