FileRoot

java.lang.Object
- rootio.FileRoot

```
public class FileRoot
extends Object
```
Class to read ROOT files. To get directory inside the file, use "cd()" method. You can get any objects inside a ROOT file as using keys as:
key1 = rr.getKey("dir1")
dir1=key1.getObject()
key2=dir1.getKey("dir2")
dir2=key2.getObject()
key3=dir2.getKey("Histogram")
h1d=H1D( key3.getObject() )

Constructor Summary

Constructors
Constructor and Description

FileRoot(String file)
Main constructor to build root file reader.

FileRoot(URL url)
Open file from URL

Constructors
Constructor and Description
`FileRoot(String file)` Main constructor to build root file reader.
`FileRoot(URL url)` Open file from URL

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`TDirectory`	`cd(String dir)` Navigate to a directory inside the ROOT file.
`Object`	`get(String skey)` Get object associated with the key name in the current directory.
`H1D`	`getH1D(String skey)` Get H1D histogram associated with the key name.
`H2D`	`getH2D(String skey)` Get H2D histogram associated with the key name.
`List`	`getInfo()` Get the StreamerInfo
`TKey`	`getKey(int i)` Get a key using its index.
`TKey`	`getKey(String skey)` Get a key
`ArrayList<String>`	`getKeys()` Return all keys of the current directory as a list.
`int`	`getNKeys()` Get number of objects in the current directory of a ROOT file.
`Object`	`getObject(int i)` Get object associated with the key name in tthe current directory.
`Object`	`getObject(String skey)` Get object associated with the key name in the current directory.
`P1D`	`getP1D(String skey)` Get P1D associated with the key name.
`RootFileReader`	`getReader()` Returns RootFileReader
`String`	`getTitle()` Get ROOT title
`int`	`getVersion()` Get ROOT version
`String`	`toString()` Return all root objects in form of a string.

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - FileRoot
```
public FileRoot(String file)
```
    Main constructor to build root file reader.
    
    Parameters:
    
    file - Input root file
  - FileRoot
```
public FileRoot(URL url)
```
    Open file from URL
    
    Parameters:
    
    url - Input URL file
- Method Detail
  - cd
```
public TDirectory cd(String dir)
```
    Navigate to a directory inside the ROOT file.
    
    Parameters:
    
    directory - inside the file. Use the standard unix path, i.e. dir1/dir2/dir3
  - toString
```
public String toString()
```
    Return all root objects in form of a string. Use cd(dir) to navigate to a specific directory
    
    Overrides:
    
    toString in class Object
    
    Returns:
    
    a string showing all ROOT objects in the current directory
  - getKeys
```
public ArrayList<String> getKeys()
```
    Return all keys of the current directory as a list.
    
    Returns:
    
    a list of all keys for the current directory
  - getVersion
```
public int getVersion()
```
    Get ROOT version
    
    Returns:
    
    ROOT version
  - getNKeys
```
public int getNKeys()
```
    Get number of objects in the current directory of a ROOT file.
    
    Returns:
    
    number of objects
  - getTitle
```
public String getTitle()
```
    Get ROOT title
    
    Returns:
    
    ROOT title
  - getKey
```
public TKey getKey(int i)
```
    Get a key using its index. Can be called after navigation to a directory using the cd() method.
    
    Parameters:
    
    i - index of this key
    
    Returns:
    
    TKey object.
  - getInfo
```
public List getInfo()
```
    Get the StreamerInfo
    
    Parameters:
    
    streamer - info
  - getKey
```
public TKey getKey(String skey)
```
    Get a key
    
    Parameters:
    
    skey - key name
    
    Returns:
    
    TKey object.
  - getReader
```
public RootFileReader getReader()
```
    Returns RootFileReader
    
    Returns:
    
    RootFileReader
  - getH1D
```
public H1D getH1D(String skey)
```
    Get H1D histogram associated with the key name. It is assumed that this ROOT key keeps histogram (TH1).
    
    Parameters:
    
    skey - key name
    
    Returns:
    
    H1D histogram
  - getH2D
```
public H2D getH2D(String skey)
```
    Get H2D histogram associated with the key name. It is assumed that this ROOT key keeps histogram (TH1).
    
    Parameters:
    
    skey - key name
    
    Returns:
    
    H2D histogram
  - getP1D
```
public P1D getP1D(String skey)
```
    Get P1D associated with the key name. It corresponds to TGraph in ROOT. It is assumed that this ROOT key keeps histogram (TH1).
    
    Parameters:
    
    skey - key name
    
    Returns:
    
    P1D object representing TGraph inside ROOT file
  - get
```
public Object get(String skey)
```
    Get object associated with the key name in the current directory. The mapping is as following:
    TGraph will be returned as P1D object
    TH1F or TH1D will be returned as H1D object
    TH2F or TH2D will be returned as H2D object
    other objects will be returned as in hep.io.root.interfaces.
    
    Parameters:
    
    skey - key name
    
    Returns:
    
    Object depending on the key.
  - getObject
```
public Object getObject(String skey)
```
    Get object associated with the key name in the current directory.
    
    Parameters:
    
    skey - key name
    
    Returns:
    
    Object
  - getObject
```
public Object getObject(int i)
```
    Get object associated with the key name in tthe current directory.
    
    Parameters:
    
    i - key index
    
    Returns:
    
    Object

Class FileRoot

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

FileRoot

FileRoot

Method Detail

cd

toString

getKeys

getVersion

getNKeys

getTitle

getKey

getInfo

getKey

getReader

getH1D

getH2D

getP1D

get

getObject

getObject