Simple Wave Extract

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Hi all,
Here I'm trying to copy multiple 1-D waves into an INDEX-D wave, where the 1-D waves vary between 3000-4000 points. But somehow, the code keeps copying the last value of the 1D wave until it reaches 5000th. 

make/O/N = (5000, index) SubWave
	Variable NewInd = 0
 	Variable Col = 0
 	do		
 			Wave/Z w = WaveRefIndexed("", newInd, 4)	// Next wave in current data folder
		if (!WaveExists(w))
			break				// No more waves
		endif
 
			SubWave[][Col] = w[p]      // Copy wave w into SubWave 
 		NewInd += 1 	
 		Col  += 1
 	while (1)


I also tried an alternative:

make/O/N = (5000, index) SubWave
	Variable NewInd = 0
 	Variable Col = 0
 	do		
 			Wave/Z w = WaveRefIndexed("", newInd, 4)	// Next wave in current data folder
		if (!WaveExists(w))
			break				// No more waves
		endif
                Variable i =0
                do
		   SubWave[i][Col] = w[i][0]    //copy the i-th row of w to the i-th row of the SubWave while the i-th row is not 'not a number' 
                   i += 1
 		while(numtype(w[i][0]!=NaN)        
                NewInd += 1 	
 		Col  += 1
 	while (1)


This looks pretty obvious to me, but it doesn't work. Another solution is to get the number of data points of the wave I want to copy, and create a while-loop etc. Is there a way to get the length of a wave (something similar to 'strlen')? Thanks.
-Cheers
Igor's method for avoiding crashes caused by reading past the end of a wave is to return the last point of the wave when the index is past the end. If you change rtGlobals=1 at the top of your procedure to rtGlobals=3, that out-of-range index will cause an error (that's actually a Good Thing).

You don't have to write a loop, you can use subrange indexing on the left side:

SubWave[0,numpnts(w)-1][Col] = w[p]

This line assumes that w is a 1D wave. You can read more than you ever wanted to know about these topics by executing the following command:

DisplayHelpTopix "Waveform Arithmetic and Assignment"

John Weeks
WaveMetrics, Inc.
support@wavemetrics.com

December 9, 2011 at 09:21 am - Permalink
Thanks! I also found a way to treat the problem. It's less elegant than the sub-range method, but it works.
At this point, I have one final problem: save my files in a "strange format"; something like this: dat.001, dat.002... dat.010, dat.011,...dat.999 (999 being the maximum number, Line 26) instead of dat.1, dat.2 etc. Any hints?Thanks


Function/S SaveAllNumeric2DWaveToTextFiles(pathName)
	String pathName		// Name of Igor symbolic path
 	String fileNameList = ""
 	Variable index = 0
	Variable name = 1
	do
		Wave/Z w1 = WaveRefIndexed("", index, 4)	// Next wave in current data folder ==ZSensor_Ext
		Wave/Z w2 = WaveRefIndexed("",index+1,4) //Next+1 wave in current data folder ==Defl_Ext
		if (!WaveExists(w1))
			break				// No more waves
		endif
 
		if (WaveDims(w1) != 1)
			index += 1
			continue			// 1D waves only
		endif
		index += 2                  //treat the next two files
		
		Variable i = 0             //<<<<<<<<<<<< LINE 17	                                    
		Variable PTs = numpnts(w1)
		Make/O/N=(PTs,3) SubWave
		Do
			SubWave[i][0]=w1[i]*10^9     // ZSensor in nanometer is assigned to SubWave column 1
			SubWave[i][1]=0
			SubWave[i][2]=w2[i]*10^9     //Deflection in nm is assigned to SubWave column 3
			i += 1
		While(i<=PTs)           //<<<<<<<<<<<< LINE 25
		
		String fileName = "dat."+ num2istr(name)  // Convert integer 'name' into string (trying to get dat.001, dat.002 instead of dat.1, dat.2...)
		Save /P=$pathName /J /O  SubWave as fileName	// Save to text file
		fileNameList += fileName + ";"	
		name += 1
	while(1)
	printf "%03.0f\r" name   //<<<<<<<<<<<<< LINE 31
	return fileNameList
End

December 9, 2011 at 12:18 pm - Permalink
save my files in a "strange format"; something like this: dat.001, dat.002... dat.010, dat.011,...dat.999 (999 being the maximum number, Line 26) instead of dat.1, dat.2 etc.


Change this:

String fileName = "dat."+ num2istr(name)

to this:

String fileName
sprintf fileName, "dat.%03d", name


BTW, name is not a good name for a number.

December 9, 2011 at 01:15 pm - Permalink