[R] Help with regular expressions

[Dennis Fisher]

R 3.4.2
OS X

Colleagues

I would appreciate some help with regular expressions.

I have string that looks like:
	" ITERATION              ,THETA1                 ,THETA2                 ,THETA3                 ,THETA4                 ,THETA5                 ,THETA6                 ,THETA7                 ,SIGMA(1,1)             ,SIGMA(2,1)             ,SIGMA(2,2)”

In the entries that contain:
	(X,Y)			# for example, SIGMA(1,1)
I would like to replace the comma with a period, e.g., SIGMA(1.1) but NOT the other commas

The end-result would be:
	" ITERATION              ,THETA1                 ,THETA2                 ,THETA3                 ,THETA4                 ,THETA5                 ,THETA6                 ,THETA7                 ,SIGMA(1.1)             ,SIGMA(2.1)             ,SIGMA(2.2)”

Can someone provide the regular expression code to accomplish this?
Thanks.

Dennis

Dennis Fisher MD
P < (The "P Less Than" Company)
Phone / Fax: 1-866-PLessThan (1-866-753-7784)
www.PLessThan.com