Net Income Per Share

We compute basic net income per share using the weighted average number of common shares outstanding during the period. We compute diluted net income per share using the weighted average number of common shares and potentially dilutive common shares outstanding during the period. Potentially dilutive common shares consist of common shares issuable upon vesting of restricted stock units, exercise of stock options and ESPP purchase rights, and conversion of the 4.00% Debentures using the treasury stock method, if dilutive.

The following provides the computation of basic and diluted net income per share:



	Three months ended October 31,						Nine months ended October 31,
	2014			2013			2014		2013
Net income attributable to Mentor Graphics shareholders	$	21,030		$	25,535		$	32,651	$	49,722
Noncontrolling interest adjustment to redemption value	(267		)	(2,032		)	1,295		(3,913		)
Adjusted net income attributable to Mentor Graphics shareholders	$	20,763		$	23,503		$	33,946	$	45,809
Weighted average common shares used to calculate basic net income per share	114,405			113,986			114,399		113,232
Employee stock options, restricted stock units and employee stock purchase plan	2,310			3,092			2,529		3,163
Weighted average common and potential common shares used to calculate diluted net income per share	116,715			117,078			116,928		116,395
Net income per share attributable to Mentor Graphics shareholders:
Basic net income per share	$	0.18		$	0.21		$	0.30	$	0.40
Diluted net income per share	$	0.18		$	0.20		$	0.29	$	0.39

We excluded from the computation of diluted net income per share 1,677 shares of common stock for stock options and restricted stock units for the three months ended October 31, 2014 and 1,189 shares of common stock for stock options and restricted stock units for the nine months ended October 31, 2014 compared to 73 shares of common stock for stock options for the three months ended October 31, 2013 and 1,238 shares of common stock for stock options, restricted stock units and ESPP purchase rights for the nine months ended October 31, 2013. These stock options, restricted stock units, and ESPP purchase rights were determined to be anti-dilutive as a result of applying the treasury stock method.

We decreased the numerator of our basic and diluted earnings per share calculation by $(267) for the three months ended October 31, 2014 for the increase of the noncontrolling interest with redemption feature to its calculated redemption value, recorded directly to retained earnings. We increased the numerator of our basic and diluted earnings per share calculation by $1,295 for the nine months ended October 31, 2014 for the decrease of the noncontrolling interest with redemption feature to its calculated redemption value, recorded directly to retained earnings. We decreased the numerator of our basic and diluted earnings per share calculation by $(2,032) for the three months ended October 31, 2013 and $(3,913) for the nine months ended October 31, 2013 for the increase of the noncontrolling interest with redemption feature to its calculated redemption value, recorded directly to retained earnings.

We assume that the 4.00% Debentures will be settled in common stock for purposes of calculating their dilutive effect. The assumed conversion of the 4.00% Debentures was anti-dilutive for all periods and therefore excluded from the computation of diluted net income per share. The conversion feature of the 4.00% Debentures, which allow for settlement in cash or a combination of cash and common stock, are further described in Note 7. “Notes Payable.”