Regular Expressions

To match a floating point value in a substring I currently use the following regular expression:

(\d+(?:\.\d+)?(?:[eE][-+]?[0-9]+)?)

This matches:

• 123
• 123.4
• 123.4E3
• 123.4e-4
• etc...

Does anyone have a better expression that matches example strings?
Please post in the comments below, thanks.