"Can't use $ in this way in a function"

<br />
	for(pas=0;pas<NbrDeWave;pas=pas+1)	<br />
	<br />
	NomWave=StringFromList(pas,NomDesWaves,";")	<br />
	NomWave=StringFromList(1,NomWave,"'")	<br />
<br />
     Wave w = $NomWave     //get wave reference<br />
<br />
	print NomWave<br />
     MaxWave=WaveMax(w)     //use wave reference here, too<br />
	print MaxWave<br />
	<br />
     w = w / MaxWave     //$NomWave=$NomWave/MaxWave<br />
						<br />
	endfor											<br />

Function/S NormaliserGraph()

string NomDesWaves

variable NbrDeWave,MaxWave,pas

string NomWave



NomDesWaves=TraceNameList("", ";", 1 )

NbrDeWave=ItemsInList(NomDesWaves)

print NomDesWaves

print NbrDeWave

	

	

	for(pas=0;pas
	

	NomWave=StringFromList(pas,NomDesWaves,";")	

	NomWave=StringFromList(1,NomWave,"'")	

	

     Wave w = $NomWave     //get wave reference

     Duplicate /O w, $NomWave+"-AvantNorm"

     

	print NomWave

	

     MaxWave=WaveMax(w)     //use wave reference here, too

     	print MaxWave

     	

     if (MaxWave==1)

     	print "Il semble que le graph "+NomWave+" soit déjà normalisé" 						// Execute if condition is TRUE

     else

     	    Duplicate /O w, $NomWave+"-AvantNorm"

     	    w = w / MaxWave    					// Optionally execute if condition is FALSE

     endif

     

	endfor	

	

	

return("1")

End

neogin wrote: Thanks; it works perfectly !

if there is people interested here's the final code.

Function/S NormaliserGraph()

	string NomDesWaves
	variable NbrDeWave,MaxWave,pas
	string NomWave

	NomDesWaves=TraceNameList("", ";", 1 )
	NbrDeWave=ItemsInList(NomDesWaves)
	print NomDesWaves
	print NbrDeWave
	
	for(pas=0;pas<NbrDeWave;pas=pas+1)
	
		NomWave=StringFromList(pas,NomDesWaves,";")	
		NomWave=StringFromList(1,NomWave,"'")	
	
		Wave w = $NomWave     //get wave reference
		Duplicate /O w, $NomWave+"-AvantNorm"
     
		print NomWave
	
		MaxWave=WaveMax(w)     //use wave reference here, too
		print MaxWave
     	
		if (MaxWave==1)
			print "Il semble que le graph "+NomWave+" soit déjà normalisé" 	// Execute if condition is TRUE
		else
			Duplicate /O w, $NomWave+"-AvantNorm"
			w = w / MaxWave    					// Optionally execute if condition is FALSE
		endif
     
	endfor	
	
	return("1")
End

I have an instance of this error that I don't understand.

Function VSAnalysis()

Variable  SampleRate,TrackLength
Variable TrackTime, t, n,TrackLengthShort
variable i=0,j=0, t_perm
 

variable p
String LFWaveString
Variable Speed1,Speed2


	//Need to loop through all waves in folder
	//Keep data folder untouched, work in analysis folder
variable WaveCount = CountObjectsDFR(::, 1 )	// waves in parent folder

for (p=0; p<WaveCount;p+=1)
	LFWaveString = GetIndexedObjNameDFR(::,1,p)
	Wave LFWave = ::$LFWaveString

	// Get speed1 and speed2
	String regExp = "([[:digit:]]+), ([[:digit:]]+)"
	SVAR Speed1Str, Speed2Str
	SplitString /E=(regExp) LFWaveString, Speed1Str, Speed2Str
	Speed1 = $Speed1Str
	Speed2 = $Speed2Str

The error is on "Speed1 = $Speed1Str".  I guess this should involve some problem with runtime lookup of globals without declaring them correctly, but LFWaveString is local and it seems like substring Speed1Str should also be local, so there should be no problem.  Changing String declarations to SVAR as I tried above doesn't help. 

Speed1 and Speed2 are numeric variables, not references to anything global, so the $ operator isn't what you need here. Instead, you need to do something to Speed1Str and Speed2Str to get a number from them. The easy way is str2num():

    Speed1 = str2num(Speed1Str)
    Speed2 = str2num(Speed2Str)

There are other variations on this to handle some corner cases, but str2num() probably covers 99% of cases.

Let us know if that's not what you intended.

Thank you, that immediately fixed it. I've just reviewed the string substitution help file and I think I understand better now.