# numpy.tri() in Python

numpy.tri(R, C = None, k = 0, dtype = ‘float’) : Creates an array with 1’s at and below the given diagonal(about k) and 0’s elsewhere.
Parameters :

```R     : Number of rows
C     : [optional] Number of columns; By default R = C
k     : [int, optional, 0 by default]
Diagonal we require; k>0 means diagonal above main diagonal or vice versa.
dtype : [optional, float(byDefault)] Data type of returned array.
```

 `# Python Program illustrating ` `# numpy.tri method ` ` `  `import` `numpy as geek ` ` `  `print``(``"tri with k = 1 : \n"``,geek.tri(``2``, ``3``, ``1``, dtype ``=` `float``), ``"\n"``) ` ` `  `print``(``"tri with main diagonal : \n"``,geek.tri(``3``, ``5``, ``0``), ``"\n"``) ` ` `  `print``(``"tri with k = -1 : \n"``,geek.tri(``3``, ``5``, ``-``1``), ``"\n"``) `

Output :

```tri with k = 1 :
[[ 1.  1.  0.]
[ 1.  1.  1.]]

tri with main diagonal :
[[ 1.  0.  0.  0.  0.]
[ 1.  1.  0.  0.  0.]
[ 1.  1.  1.  0.  0.]]

tri with k = -1 :
[[ 0.  0.  0.  0.  0.]
[ 1.  0.  0.  0.  0.]
[ 1.  1.  0.  0.  0.]]
```

References :
https://docs.scipy.org/doc/numpy/reference/generated/numpy.tri.html
Note :
These NumPy-Python programs won’t run on onlineID, so run them on your systems to explore them
.
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