# computeVolume

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Description: This method computes the volume attribute of the max-tree nodes.

Signature: volume = MaxTreeAlpha.computeVolume()

Input:

Output:
• volume: 1d-array, int32. Array containing the volume attribute of the max-tree nodes.

# C++ Aux Function

```OK
```
```OK [C/C++ extension is up-to-date]
```

# Python Implementation

``` 1 import numpy as np
2
3 def computeVolume(self):
4     """
5     This method returns the volume attribute of the max-tree nodes.
6     """
7     parent = self.node_array[0,:]
8     level  = self.node_array[2,:]
9     area   = self.node_array[3,:]
10     volume = area.copy()
11     delta = (level - level[parent]).astype(np.int32)
12     self.compute_volume_aux(parent,delta,area,volume)
13     return volume
```

# Example

``` 1 from max_tree_alpha import MaxTreeAlpha
2 import numpy as np
3
4
5 img = np.array([[9,10, 3, 3, 3, 5, 8],
6                 [2, 0, 4, 0, 0, 0, 7],
7                 [8, 0, 5, 0, 6, 0, 9],
8                 [9, 0, 6, 0, 8, 4, 2]],dtype = np.uint8)
9
10 Bc = np.ones((3,3), dtype = bool)
11
12
13 mxt = MaxTreeAlpha(img,Bc)
14 volume = mxt.computeVolume()
15
16 g= mxt.generateGraph(nodes_attr = volume)
17 mmgraphviz(g, title='Max-tree (node:h [volume])')
```