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BGROW directive

Adds new branches to a node of a tree.

No options

Parameters

TREE = trees Trees to be extended
NODE = scalars Node at which to extend each tree
NBRANCHES = scalars Number of branches to add to each node; default 2
POSITION = scalars Position at which to add the branches to each node; default * i.e. after all the current braches from the node
NEWNODES = variates Returns the number(s) allocated to the new nodes

Description

BGROW provides the basic tree utility of adding new branches at a node, which is used for example by the BCONSTRUCT procedure. Other tree utilities are described in the description of the TREE directive (which declares and initializes a tree).

The tree to be extended is specified by the TREE parameter, and the NODE parameter indicates the node at which the new branches are to be added. The NBRANCHES parameter specifies the number of branches to add. The POSITION specifies where to add them if the node is a non-terminal node; by default they are added after all the branches currently from the node. The NEWNODES parameter saves a variate containing the numbers of the new nodes (i.e. the terminal nodes at the ends of the new branches).

Options: none.

Parameters: TREE, NODE, NBRANCHES, POSITION, NEWNODES.

See also

Directives: BASSESS, BCUT, BJOIN, TREE.

Procedures: BCONSTRUCT, BCLASSIFICATION, BGRAPH, BKEY, BPRINT, BPRUNE.

Functions: BBELOW, BBRANCHES, BDEPTH, BMAXNODE, BNBRANCHES, BNEXT, BNNODES, BPATH, BPREVIOUS, BSCAN, BTERMINAL.

Commands for: Calculations and manipulation.

Example

" Examples 1:4.12.3, 1:4.12.4 & 1:4.12.5 "
" Declare the original tree."
TREE      T
" Define texts to use as labels for the nodes."
TEXT      Lab[1...26]; VALUES=\
          'a','b','c','d','e','f','g','h','i','j','k','l','m',\
          'n','o','p','q','r','s','t','u','v','w','x','y','z'
" Define information at root to be a pointer
  with a single element called 'label'."
POINTER   [NVALUES=!t(label)] T[1]
" Set that element to the first value of Lab, i.e. 'a'."
TEXT      T[1]['label']; VALUE=Lab[1]
" Display the tree - first with labels of nodes, then with numbers."
BPRINT    [PRINT=labelleddiagram,numbereddiagram] T
" Extend the tree by forming 3 branches from node 1 (root)."
BGROW     T; NODE=1; NBRANCH=3; NEWNODES=Gnew
" Define the information for the new nodes."
POINTER   [NVALUES=!t(label)] T[#Gnew]
TEXT      T[#Gnew]['label']; VALUE=Lab[#Gnew]
" Display the extended tree."
BPRINT    [PRINT=labelleddiagram,numbereddiagram] T
" Find the node number of the first terminal node "
CALCULATE N1 = BTERMINAL(T; 0)
" and then the second terminal node."
CALCULATE N2 = BTERMINAL(T; N1)
PRINT     N1,N2; DECIMALS=0
" Extend the tree by adding 2 branches at the second
  and then the first terminal node."
BGROW     T; NODE=N2; NBRANCH=2; NEWNODES=Gnew2
" Define the information for the new nodes."
POINTER   [NVALUES=!t(label)] T[#Gnew2]
TEXT      T[#Gnew2]['label']; VALUE=Lab[#Gnew2]
BGROW     T; NODE=N1; NBRANCH=2; NEWNODES=Gnew1
POINTER   [NVALUES=!t(label)] T[#Gnew1]
TEXT      T[#Gnew1]['label']; VALUE=Lab[#Gnew1]
" Display the extended tree."
BPRINT    [PRINT=labelleddiagram,numbereddiagram] T
"4.12.4 Remove the branches below N2, saving these as tree T2;
  also save and print the node mapping variates."
BCUT      T; NODE=N2; CUTTREE=T2; OLDNODES=Oldn;\
          NEWNODES=Newn; CUTNODES=Cutn
PRINT     [ORIENT=across] Oldn,Newn,Cutn; FIELD=3; DECIMALS=0
" Display the modified tree, and the cut-tree."
BPRINT    [PRINT=labelleddiagram,numbereddiagram] T,T2
" Redefine the root of the cut tree so that it no
  longer shares the same information pointer as the
  node where the cut was made in the original tree." 
POINTER   [NVALUES=!t(label)] T2root
TEXT      T2root['label']; VALUE='t2root'
ASSIGN    T2root; T2; 1
BPRINT    [PRINT=labelleddiagram] T2
" Use BCUT to form T3 as a duplicate of T
  but with renumbered nodes."
BCUT      [RENUMBER=yes] T; NEWTREE=T3
BPRINT    [PRINT=labelleddiagram,numbereddiagram] T3
"4.12.5 Join tree T2 onto node 4 of T3; save and print the
  numbers of the joined nodes in the revised tree."
BJOIN     T3; NODE=4; JOINTREE=T2; NEWNODES=Jnew
BPRINT    [PRINT=labelleddiagram,numbereddiagram] T3
PRINT     Jnew; DECIMALS=0
" Tree functions: all nodes below node 2,"
CALCULATE Below  = BBELOW(T3; 0; 0)
PRINT     Below; DECIMALS=0
" all terminal nodes below node 2,"
CALCULATE Below0 = BBELOW(T3; 0; 0)
PRINT     Below0; DECIMALS=0
" first three terminal nodes,"
CALCULATE N1 = BTERMINAL(T3; 0)
&         N2 = BTERMINAL(T3; N1)
&         N3 = BTERMINAL(T3; N2)
PRINT     N1,N2,N3; DECIMALS=0
" nodes and branches on path to N3,"
CALCULATE Pn3 = BPATH(T3; N3)
&         Ln3 = BBRANCHES(T3; N3)
PRINT     Pn3,Ln3; DECIMALS=0
" depth and number of branches at node 2,"
CALCULATE Nn2 = BNBRANCHES(T3; 2)
&         Dn2 = BDEPTH(T3; 2)
PRINT     Nn2,Dn2; DECIMALS=0
" next nodes on branches 1-3 from node 1,
  and branch 1 from node 2."
PRINT     BNEXT(T3; 1; 1); DECIMALS=0
PRINT     BNEXT(T3; 1; 2); DECIMALS=0
PRINT     BNEXT(T3; 1; 3); DECIMALS=0
PRINT     BNEXT(T3; 2; 1); DECIMALS=0
" Scan the tree, taking the nodes in standard order."
SCALAR    Scan[0]; value=0
CALCULATE Scan[1] = BSCAN(T3; Scan[0])
&         Scan[2] = BSCAN(T3; Scan[1])
&         Scan[3] = BSCAN(T3; Scan[2])
&         Scan[4] = BSCAN(T3; Scan[3])
&         Scan[5] = BSCAN(T3; Scan[4])
&         Scan[6] = BSCAN(T3; Scan[5])
&         Scan[7] = BSCAN(T3; Scan[6])
&         Scan[8] = BSCAN(T3; Scan[7])
&         Scan[9] = BSCAN(T3; Scan[8])
PRINT     Scan[1...9]; FIELD=8; DECIMALS=0

Updated on March 8, 2019

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