Arrays

In [68]:

    

#Array declaration

a = [1,4,2,9,3,5]


    

    
Out[68]:





6-element Array{Int64,1}:
 1
 4
 2
 9
 3
 5

In [69]:

    

b = [1 4 2 7 3 5]


    

    
Out[69]:





1×6 Array{Int64,2}:
 1  4  2  7  3  5

In [70]:

    

c = [1 2; 2 4; 5 6]


    

    
Out[70]:





3×2 Array{Int64,2}:
 1  2
 2  4
 5  6

In [71]:

    

# ndims returns the number of dimensions of an array
ndims(c)


    

    
Out[71]:





2

In [72]:

    

# size returns a tuple with the dimensions of an array
size(c)


    

    
Out[72]:





(3,2)

In [73]:

    

#Returns a subset of array

getindex(a, 2:3)


    

    
Out[73]:





2-element Array{Int64,1}:
 4
 2

In [74]:

    

# the view function is like getindex(), but returns a view into the parent array with the given indices instead of making a copy.
x =view(a, 2:3)


    

    
Out[74]:





2-element SubArray{Int64,1,Array{Int64,1},Tuple{UnitRange{Int64}},true}:
 4
 2

In [75]:

    

#Creates a SubArray from an indexing expression, should not be used as the target of an assignment (e.g. @view(A[1,2:end]) = ...)

@view a[2:end]


    

    
Out[75]:





5-element SubArray{Int64,1,Array{Int64,1},Tuple{UnitRange{Int64}},true}:
 4
 2
 9
 3
 5

In [76]:

    

#parent returns the ”parent array” of an array view type
parent(x)


    

    
Out[76]:





6-element Array{Int64,1}:
 1
 4
 2
 9
 3
 5

In [77]:

    

# parentindexes returns the corresponding indexes in the parent
parentindexes(x)


    

    
Out[77]:





(2:3,)

In [78]:

    

# slicedim() return all the data where the index for dimension d equals i

slicedim(c,1,2)


    

    
Out[78]:





2-element Array{Int64,1}:
 2
 4

In [79]:

    

# setindex!(A, X, inds...) stores values from array X within some subset of A as specified by

y = [7,8]
setindex!(a, y,2:3)


    

    
Out[79]:





6-element Array{Int64,1}:
 1
 7
 8
 9
 3
 5

In [81]:

    

# isassigned(array, i) tests whether the given array has a value associated with index i
isassigned(a, 10)


    

    
Out[81]:





false

In [83]:

    

# vcat(A...) concatenates along dimension 1


    

    
Out[83]:





8-element Array{Int64,1}:
 1
 7
 8
 9
 3
 5
 7
 8

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