how to change values of a column

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I am a beginner of Igor pro. Is there a way to do operations (such as add, subtract, multiply some value) to all the data in a column? I know Origin can do that easily. Can Igor also? Thanks.
Very simple. Here you go (assume you have three waves, wave0, wave1, wave2 that ALREADY EXIST):

Wave0 += 5   // add 5 to all the entries.
Wave0 = Wave0 * 2   //multiply all the entries in wave0 by 2.

Wave2 = wave0 + 2*wave1   //add two times wave1 to wave0 and put the results in wave2


You should take the intro tour next:
DisplayHelpTopic "Getting Started"

December 23, 2010 at 07:48 pm - Permalink

hi I know the post is a little old but I think my question fits in here. Does anyone know how to change the value of several waves at the same time, so eg multiply wave0 wave1 and wave3 by 5? I have lots of waves and dont want to type the command 100 times.

Thanks

January 21, 2013 at 12:05 am - Permalink

you can work with lists, e.g.

Function MultiplyWaves(list)
    String list         // A semicolon-separated list.         

    String theWave
    Variable index=0

    do
        theWave = StringFromList(index, list)
        if (strlen(theWave) == 0)
            break                           // Ran out of waves
        endif

        wave w = $theWave             //create wave reference  
        w *=5
       
        index += 1
    while (1)                           // Loop until break above
End


then execute e.g.;

MultiplyWaves("wave0;wave1;wave3")


This techniques ist described in the manual, just execute

DisplayHelpTopic "Processing Lists of Waves"

January 21, 2013 at 02:49 am - Permalink

hellas23 wrote:
hi I know the post is a little old but I think my question fits in here. Does anyone know how to change the value of several waves at the same time, so eg multiply wave0 wave1 and wave3 by 5? I have lots of waves and dont want to type the command 100 times.

Thanks


You can also use the Data Browser for this. Select your waves in the data browser and then click the "Execute Cmd..." button. Then change the default "Display %s" command to your calculation, and use "%s" for the current selection, so as an example to add a value of 5 to the selected waves you would do the following:

%s+=5

Be sure the selection is only waves, as this will change the value of variables as well.

January 21, 2013 at 09:13 am - Permalink

tkessler wrote:

You can also use the Data Browser for this. Select your waves in the data browser and then click the "Execute Cmd..." button. Then change the default "Display %s" command to your calculation, and use "%s" for the current selection, so as an example to add a value of 5 to the selected waves you would do the following:

%s+=5


This was really helpful, thank you.
I know this post is old, but I have a related question : using the "%s" command it is easy to change Y values for waves, however I could not figure how to affect the X values.
I have a bunch of waves that need to be shifted in the X direction, is the same way as the Arithmetic package allows, but I wish to do it all at once for all the waves. Any idea ?

Thanks

April 26, 2018 at 10:42 pm - Permalink

Just the same way as for y values:
Using the data browser, the following command is created using the %s syntax and "Execute once for all selected items".
setscale /p x, 5,10, "", root:w3,root:w2,root:w1,root:w0
This also works directly from the command line
setscale /p x, 5,10, "", w0,w1,w2,w3.

Note: All the waves will get the same "x-settings" (see displayhelptopic "Setscale" for details). To preserve individual features, you will need to run it one by one and recall the settings via DimDelta, DimOffset, DimSize, or WaveUnits for each wave.

HJ

April 27, 2018 at 12:41 am - Permalink