Error in FFT example from manual. "Complex wave used in real expression"

The code was designed to be run from a Macro or command line many years ago.

Putting the code into a function wasn't tried after Igor added more stringent checking of wave reference types.

That checking is placated by using a WAVE/C wave reference on the FFT result:

Function fComplexFromManual()

	// Make a time domain waveform
	Make/O/N=1024 wave0
	SetScale x 0, 1, "s", wave0   // goes from 0 to 1 second
	wave0=sin(2*PI*x)+sin(6*PI*x)/3+sin(10*PI*x)/5+sin(14*PI*x)/7
	Display wave0 as "Time Domain"

	// Do the FFT
	Duplicate/O wave0, cwave0				// get copy to do FFT on
	FFT cwave0								// cwave0 is now complex...
	WAVE/C cw0 = cwave0						// ... so we need a complex wave ref
	cw0 /= 512;cw0[0] /= 2					// normalize amplitude
	Display cw0 as "Frequency Domain";SetAxis bottom, 0, 25

	// Calculate magnitude and phase
	Make/O/N=513 mag0, phase0, power0			// these are real waves
	CopyScales cw0, mag0, phase0, power0
	mag0 = real(r2polar(cw0))
	phase0 = imag(r2polar(cw0))
	phase0 *= 180/PI									// convert to degrees
	Display mag0 as "Magnitude and Phase";AppendToGraph/R phase0
	SetAxis bottom, 0, 25
	Label left, "Magnitude";Label right, "Phase"

	// Calculate power spectrum
	power0 = magsqr(cw0)
	Display power0 as "Power Spectrum";SetAxis bottom, 0, 25
End

This version runs in both a function and in a macro (macros don't permit or need WAVE statements):

// Make a time domain waveform
Make/O/N=1024 wave0
SetScale x 0, 1, "s", wave0			// goes from 0 to 1 second
wave0=sin(2*PI*x)+sin(6*PI*x)/3+sin(10*PI*x)/5+sin(14*PI*x)/7
Display wave0 as "Time Domain"

// Do the FFT
FFT/DEST=cwave0 wave0              // cwave0 is created complex, 513 points
cwave0 /= 512;cwave0[0] /= 2       // normalize amplitude
Display cwave0 as "Frequency Domain";SetAxis bottom, 0, 25

// Calculate magnitude and phase
Make/O/N=513 mag0, phase0, power0  // these are real waves
CopyScales cwave0, mag0, phase0, power0
mag0 = real(r2polar(cwave0))
phase0 = imag(r2polar(cwave0))
phase0 *= 180/PI                   // convert to degrees
Display mag0 as "Magnitude and Phase";AppendToGraph/R phase0
SetAxis bottom, 0, 25
Label left, "Magnitude";Label right, "Phase"

// Calculate power spectrum
power0 = magsqr(cwave0)
Display power0 as "Power Spectrum";SetAxis bottom, 0, 25