Graph: Graph object
In flahn/openeo-r-client: openEO client interface

Description Details Value Fields Methods Arguments Examples

This class represents an openeo process graph. It consists of ProcessNodes and optional ProcessGraphParameter. The creation of a Graph is not required in most cases, because this will otherwise be done automatically in those function that have to send a Graph representation to the openEO service. In those cases you can pass on a function that results a ProcessNode or a result node itself.

However, you might want to perform an explicit cast with as(x,"Graph") in order to obtain a Graph object. 'x' can be the afore mentioned function or ProcessNode, and also a ProcessGraph object that can be obtained by describe_user_process, which parses the stored Graph representation into an openEO Graph object (parse_graph).

Object of R6Class with methods for building an openeo process graph

data: a named list of collection ids or process graph parameters depending on the context

$new(con = NULL, final_node=NULL): The object creator created from processes and available data.
$getNodes(): a function to return a list of created ProcessNodes for this graph
$serialize(): creates a list representation of the graph by recursively calling $serialize
$validate(): runs through the nodes and checks the validity of its argument values
$getNode(node_id): searches and returns a node from within the graph referenced by its node id
$addNode(node)
$removeNode(node_id): removes a process node from the graph
$getFinalNode(): gets the result process node of a process graph
$setFinalNode(node): sets the result process node by node id or a ProcessNode
$getVariables(): creates a named list of the defined variables of a process graph
$setVariables(list_of_vars): sets the process graph parameter (variables) of graph

con: openeo connection (optional) otherwise active_connection is used.
final_node: optional the final node (end node) that was used to create a graph
node_id: the id of a process node
node: process node or its node id
parameter: the name of a parameter in a process
value: the value to be set for a parameter of a paricular process
id or variable_id: the variable id
description: a description field for a variable
type: the type of variable, default 'string'
default: optional default value to be set for a variable

## Not run: 
con = connect(host="http://some.url.org/openeo")
p = processes()
...
result = p$save_result(data = prior_step, format = "PNG")
graph = as(result, "Graph")

# alternative with a function (R primitve operator are translated into openEO processes)
resulting_ndvi_function = function(x) {
 B4 = x[1]
 B8 = x[2]

 return((B8-B4)/(B8+B4))
} 

graph = as(resulting_ndvi_function, "Graph")

## End(Not run)