Update README.md

README.md

@@ -23,34 +23,4 @@ This package has been registered. So, simply type `import Pkg; Pkg.add("GreenFun
 
 ## Basic Usage
 
-```julia
-using AbstractTrees, StaticArrays, ExpressionTree
-
-# Define the type of the weight of a 4-vertex diagram
-const Weight = SVector{2,Float64} 
-
-# Define the possibilities to build a 4-vertex diagram from the left and right 4-vertex subdiagrams.
-chan = [Parquet.T, Parquet.U, Parquet.S] 
-
-# Generate the parameter for the expression tree. The second argument lists the possible number of imaginary-time variables in the bare 4-vertex (namely, the bare interaction of your model). For example, the instaneous Coulomb interaction only has one time variable, while the retared effective interaction has two time variables.
-para = Parquet.Para(chan, [1, 2]) 
-
-# Generate an expression tree for a set of 4-vertex diagrams with loop order 1, initial imaginary-time index 1, and the parameter set para.
-ver4 = Parquet.Ver4{Weight}(1, 1, para) 
-
-# use AbstractTrees interface to print/manipulate the tree
-print_tree(ver4)
-
-# [println(node) for node in Leaves(ver4)]  #print all loopNum=0 ver4
-# [println(node) for node in PostOrderDFS(ver4)]  # iterator ver4 in depth-first search (children before parents)
-# [println(node) for node in PreOrderDFS(ver4)]  # iterator ver4 (parents before children)
-
-# You can also use ete3 python3 package to visualize tree
-Parquet.showTree(ver4, para, verbose = 1, depth = 3)
-
-# You can also print tree to a newick format file, there are many visualization software for the newick format
-io = open("./test.newick", "w")
-write(io, Parquet.newick(ver4))
-close(io)
-```