diff options
Diffstat (limited to 'julia.html.markdown')
| -rw-r--r-- | julia.html.markdown | 49 |
1 files changed, 22 insertions, 27 deletions
diff --git a/julia.html.markdown b/julia.html.markdown index 2810555e..85033aa6 100644 --- a/julia.html.markdown +++ b/julia.html.markdown @@ -9,7 +9,7 @@ filename: learnjulia.jl Julia is a new homoiconic functional language focused on technical computing. While having the full power of homoiconic macros, first-class functions, and low-level control, Julia is as easy to learn and use as Python. -This is based on Julia 0.3. +This is based on Julia 0.4. ```ruby @@ -23,7 +23,7 @@ This is based on Julia 0.3. ## 1. Primitive Datatypes and Operators #################################################### -# Everything in Julia is a expression. +# Everything in Julia is an expression. # There are several basic types of numbers. 3 # => 3 (Int64) @@ -155,7 +155,7 @@ b = [4; 5; 6] # => 3-element Int64 Array: [4, 5, 6] b[1] # => 4 b[end] # => 6 -# 2-dimentional arrays use space-separated values and semicolon-separated rows. +# 2-dimensional arrays use space-separated values and semicolon-separated rows. matrix = [1 2; 3 4] # => 2x2 Int64 Array: [1 2; 3 4] # Arrays of a particular Type @@ -255,7 +255,7 @@ e, d = d, e # => (5,4) # d is now 5 and e is now 4 empty_dict = Dict() # => Dict{Any,Any}() # You can create a dictionary using a literal -filled_dict = ["one"=> 1, "two"=> 2, "three"=> 3] +filled_dict = Dict("one"=> 1, "two"=> 2, "three"=> 3) # => Dict{ASCIIString,Int64} # Look up values with [] @@ -272,8 +272,8 @@ values(filled_dict) # Note - Same as above regarding key ordering. # Check for existence of keys in a dictionary with in, haskey -in(("one", 1), filled_dict) # => true -in(("two", 3), filled_dict) # => false +in(("one" => 1), filled_dict) # => true +in(("two" => 3), filled_dict) # => false haskey(filled_dict, "one") # => true haskey(filled_dict, 1) # => false @@ -292,7 +292,7 @@ get(filled_dict,"four",4) # => 4 # Use Sets to represent collections of unordered, unique values empty_set = Set() # => Set{Any}() # Initialize a set with values -filled_set = Set(1,2,2,3,4) # => Set{Int64}(1,2,3,4) +filled_set = Set([1,2,2,3,4]) # => Set{Int64}(1,2,3,4) # Add more values to a set push!(filled_set,5) # => Set{Int64}(5,4,2,3,1) @@ -302,10 +302,10 @@ in(2, filled_set) # => true in(10, filled_set) # => false # There are functions for set intersection, union, and difference. -other_set = Set(3, 4, 5, 6) # => Set{Int64}(6,4,5,3) +other_set = Set([3, 4, 5, 6]) # => Set{Int64}(6,4,5,3) intersect(filled_set, other_set) # => Set{Int64}(3,4,5) union(filled_set, other_set) # => Set{Int64}(1,2,3,4,5,6) -setdiff(Set(1,2,3,4),Set(2,3,5)) # => Set{Int64}(1,4) +setdiff(Set([1,2,3,4]),Set([2,3,5])) # => Set{Int64}(1,4) #################################################### @@ -346,7 +346,7 @@ end # cat is a mammal # mouse is a mammal -for a in ["dog"=>"mammal","cat"=>"mammal","mouse"=>"mammal"] +for a in Dict("dog"=>"mammal","cat"=>"mammal","mouse"=>"mammal") println("$(a[1]) is a $(a[2])") end # prints: @@ -354,7 +354,7 @@ end # cat is a mammal # mouse is a mammal -for (k,v) in ["dog"=>"mammal","cat"=>"mammal","mouse"=>"mammal"] +for (k,v) in Dict("dog"=>"mammal","cat"=>"mammal","mouse"=>"mammal") println("$k is a $v") end # prints: @@ -420,14 +420,12 @@ varargs(1,2,3) # => (1,2,3) # The ... is called a splat. # We just used it in a function definition. -# It can also be used in a fuction call, +# It can also be used in a function call, # where it will splat an Array or Tuple's contents into the argument list. -Set([1,2,3]) # => Set{Array{Int64,1}}([1,2,3]) # produces a Set of Arrays -Set([1,2,3]...) # => Set{Int64}(1,2,3) # this is equivalent to Set(1,2,3) +add([5,6]...) # this is equivalent to add(5,6) -x = (1,2,3) # => (1,2,3) -Set(x) # => Set{(Int64,Int64,Int64)}((1,2,3)) # a Set of Tuples -Set(x...) # => Set{Int64}(2,3,1) +x = (5,6) # => (5,6) +add(x...) # this is equivalent to add(5,6) # You can define functions with optional positional arguments @@ -447,7 +445,7 @@ end # You can define functions that take keyword arguments function keyword_args(;k1=4,name2="hello") # note the ; - return ["k1"=>k1,"name2"=>name2] + return Dict("k1"=>k1,"name2"=>name2) end keyword_args(name2="ness") # => ["name2"=>"ness","k1"=>4] @@ -549,12 +547,8 @@ abstract Cat # just a name and point in the type hierarchy # Abstract types cannot be instantiated, but can have subtypes. # For example, Number is an abstract type -subtypes(Number) # => 6-element Array{Any,1}: - # Complex{Float16} - # Complex{Float32} - # Complex{Float64} +subtypes(Number) # => 2-element Array{Any,1}: # Complex{T<:Real} - # ImaginaryUnit # Real subtypes(Cat) # => 0-element Array{Any,1} @@ -572,10 +566,11 @@ subtypes(AbstractString) # 8-element Array{Any,1}: # Every type has a super type; use the `super` function to get it. typeof(5) # => Int64 super(Int64) # => Signed -super(Signed) # => Real +super(Signed) # => Integer +super(Integer) # => Real super(Real) # => Number super(Number) # => Any -super(super(Signed)) # => Number +super(super(Signed)) # => Real super(Any) # => Any # All of these type, except for Int64, are abstract. typeof("fire") # => ASCIIString @@ -778,6 +773,6 @@ code_native(circle_area, (Float64,)) ## Further Reading -You can get a lot more detail from [The Julia Manual](http://docs.julialang.org/en/latest/manual/) +You can get a lot more detail from [The Julia Manual](http://docs.julialang.org/en/latest/#Manual-1) -The best place to get help with Julia is the (very friendly) [mailing list](https://groups.google.com/forum/#!forum/julia-users). +The best place to get help with Julia is the (very friendly) [Discourse forum](https://discourse.julialang.org/). |