minor fix following suggested change in frd str method · python-control/python-control@2c4ac62

Original file line number	Diff line number	Diff line change
`@@ -156,17 +156,17 @@ def __str__(self):`
`156`	`156`	`mimo = self.inputs > 1 or self.outputs > 1`
`157`	`157`	`outstr = ['Frequency response data']`
`158`	`158`
`159`		`-#mt, pt, wt = self.frequency_response(self.omega)`
`160`	`159`	`for i in range(self.inputs):`
`161`	`160`	`for j in range(self.outputs):`
`162`	`161`	`if mimo:`
`163`	`162`	`outstr.append("Input %i to output %i:" % (i + 1, j + 1))`
`164`	`163`	`outstr.append('Freq [rad/s] Response')`
`165`	`164`	`outstr.append('------------ ---------------------')`
`166`	`165`	`outstr.extend(`
`167`		`- ['%12.3f %10.4g%+10.4gj' % (w, m, p)`
`168`		`-for m, p, w in zip(real(self.fresp[j, i, :]),`
`169`		`-imag(self.fresp[j, i, :]), self.omega)])`
	`166`	`+ ['%12.3f %10.4g%+10.4gj' % (w, re, im)`
	`167`	`+for w, re, im in zip(self.omega,`
	`168`	`+real(self.fresp[j, i, :]),`
	`169`	`+imag(self.fresp[j, i, :]))])`
`170`	`170`
`171`	`171`	`return '\n'.join(outstr)`
`172`	`172`