[Term Entry] PyTorch Tensor Operations: .lgamma() (#7619)

* [Term Entry] PyTorch Tensor Operations: .lgamma()

* minor wording fixes

* Apply suggestion from @avdhoottt

* Apply suggestion from @avdhoottt

* Apply suggestion from @avdhoottt

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Author: jjwheatley

content/pytorch/concepts/tensor-operations/terms/lgamma/lgamma.md

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+---
+Title: '.lgamma()'
+Description: 'Computes the natural log of the absolute gamma function for each element in a tensor.'
+Subjects:
+  - 'Computer Science'
+  - 'Data Science'
+Tags:
+  - 'Functions'
+  - 'Math'
+  - 'PyTorch'
+  - 'Tensor'
+CatalogContent:
+  - 'intro-to-py-torch-and-neural-networks'
+  - 'paths/data-science'
+---
+
+In PyTorch, the **`.lgamma()`** function returns the natural logarithm of the absolute value of the gamma function for each element in an input [tensor](https://www.codecademy.com/resources/docs/pytorch/tensors).
+
+## Syntax
+
+```pseudo
+torch.lgamma(input, *, out=None) → Tensor
+```
+
+**Parameters:**
+
+- `input` (Tensor): Input tensor of floating point or complex numbers.
+- `out` (Optional): Output tensor to write results to.
+
+**Return value:**
+
+Returns a tensor of the same shape as the `input`, where each element is the log of the absolute gamma function of the corresponding input element.
+
+## Example
+
+The example demonstrates computing the natural logarithm of the absolute gamma function using both the functional form `torch.lgamma()` and the tensor method `.lgamma()`, then verifies both approaches produce identical results:
+
+```py
+import torch
+
+x = torch.tensor([0.5, 1.0, 2.5, 5.0, -0.5])
+
+# Functional form
+y1 = torch.lgamma(x)
+
+# Tensor method
+y2 = x.lgamma()
+
+print(y1)
+print(torch.allclose(y1, y2))
+```
+
+Here's the output of this code:
+
+```shell
+tensor([0.5724, 0.0000, 0.2847, 3.1781, 1.2655])
+True
+```