Text wave Issue

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Wed, 06/27/2018 - 06:37 am

Hello, I am trying to assign text from one wave to another, that is, I have a text wave, w1, and I am trying to assign its elements to another wave, w2, but I receive the error "a wave assignment error: "An attempt was made to treat a text wave as if it were a numeric wave."" I've tried a simplified version of what I am attempting to do: 

Function Example()

Variable i

Make/T/O w1= {"a","b","c"}
Make/T/O w2

For (i=0; i<numPnts(w1); i+=1)
					
	w2[i] = w1[i]
					
EndFor

End
And this work exactly how I would have expected it to. Any suggestions?
Hi, I ran your example as posted and it worked without issue. Created 2 text waves W1 of length 3 points and W2 of 128 with a,b, and c in the right spot. Tried on IP8. Can you supply the non-simplified code? Andy

June 27, 2018 at 06:47 am - Permalink

Yes, that example does work exactly how you would expect it to. I have a chunk of my code pasted below. It is just a snippet of the larger procedure I am working on but this section is essentially merging data, under three different conditions, inserting the data into different parts of an already existing waves. I am receiving the error for the line:

Stats_StatusFlag[FirstPoint + i] = Load_Stats_StatusFlag0[i]

These two waves are both text waves. Also, I am using Igor Pro 6.3.7.2.

        Wave EndTime, Stats_StatusFlag, Stats_Median_nm, Final_SMPS_Data
       
       
        For (i=0; i<numPnts(EndTime); i+=1)                                        
                                                                               
            If (EndTime[i] >= Load_EndTime[0])
               
                FirstPoint = i                                                     
                Break                                                          
               
            EndIf      
               
        EndFor


        For (i=0; i<numPnts(Load_EndTime); i+=1)                                   
       
            If (EndTime[FirstPoint + i] > Load_EndTime[i])                             
           
                InsertPoints FirstPoint + i, 1, EndTime                                
                EndTime[FirstPoint + i] = Load_EndTime[i]
                InsertPoints FirstPoint + i, 1, Stats_StatusFlag
                Stats_StatusFlag[FirstPoint + i] = Load_Stats_StatusFlag0[i]
                InsertPoints FirstPoint + i,1,Stats_Median_nm
                Stats_Median_nm[FirstPoint + i] = Load_Stats_Median_nm0[i]
                InsertPoints FirstPoint + i,1,Final_SMPS_Data
               
                    For (j=0; j<54; j+=1)
                   
                        Final_SMPS_Data[FirstPoint + i][j] = Sorted_SMPS_Data[i][j]
                   
                    EndFor
               
            ElseIF (EndTime[FirstPoint + i] == Load_EndTime[i])
           
                       
                If (V_Flag == 0)
               
                    DoAlert /T="Data Already Loaded",1,"Data already loaded for this time period, would you like to overwrite the current data?"
                               
                ElseIf (V_Flag ==1)
           
                    EndTime[FirstPoint + i] = Load_EndTime[i]                          
                    Stats_StatusFlag[FirstPoint + i] = Load_Stats_StatusFlag0[i]
                    Stats_Median_nm[FirstPoint + i] = Load_Stats_Median_nm0[i]
               
                    For (j=0; j<54; j+=1)
                   
                        Final_SMPS_Data[FirstPoint + i][j] = Sorted_SMPS_Data[i][j]
                   
                    EndFor
                   
                           
                EndIf
           
            Else
           
                For (i=0; i<numPnts(Load_EndTime);i+=1)                            
                                                                               
                    InsertPoints numPnts(EndTime), 1, EndTime
                    EndTime[numPnts(EndTime) - 1] = Load_EndTime[i]
                    InsertPoints numPnts(EndTime), 1, Stats_StatusFlag
                    Stats_StatusFlag[numPnts(EndTime) - 1] = Load_Stats_StatusFlag0[i]
                    InsertPoints numPnts(EndTime), 1, Stats_Median_nm
                    Stats_Median_nm[numPnts(EndTime) - 1] = Load_Stats_Median_nm0[i]
                    InsertPoints numPnts(EndTime), 1, Final_SMPS_Data
                   
                    For (j=0; j<54; j+=1)
                   
                        Final_SMPS_Data[numPnts(EndTime) - 1][j] = Sorted_SMPS_Data[i][j]
                   
                    EndFor
                   
                EndFor
           
            EndIf
           
       
        EndFor

June 27, 2018 at 07:01 am - Permalink

If you create a wave reference pointing to a text wave, you need to use the /T flag so that the Igor compiler knows it is a text wave. For example:
Function Test()
    // Make with a simple name - Creates an automatic wave reference named textwave0
    Make/O/T textwave0
    Wave/T textwave0    // This is redundant - Make already creates the wave reference

    // Make without a simple name - no automatic wave reference is created
    String name = "textwave1"
    Make/O/T/N=3 $name = "Hello"
    Wave/T tw1 = $name      // This is required because no automatic wave reference is created

    // Reference to a text wave named textwave2 that is assumed to already exist in the current data folder
    Wave/T tw2 = textwave2
End
I recommend rereading this section of the help. It takes both experimentation and rereading before if all sinks in.
DisplayHelpTopic "Wave References"

June 27, 2018 at 07:14 am - Permalink

Ahh, ok, haven't had much experience with text waves, works perfectly now. Much appreciated.

June 27, 2018 at 07:29 am - Permalink