Igor equivalent for numpy.repeat ?

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Mon, 01/04/2016 - 02:59 am

Hi all,

and Happy New Year everyone.
Is there an inbuilt Igor equivalent for the repeat function of numpy?
for an array x=[1,2,3,4], numpy.repeat(x,4) will give [1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4]

thanks for your help!!
Cheers
J-E
I don't know of an in-built function, but it is easy to make a function that does it:

Function Test()
    Make/O/N=4 data={1, 2, 3, 4}
    Rep(data, 4)
End


Function Rep(wData, vRep)
    wave wData
    variable vRep
    variable vLenData = DimSize(wData, 0)
    Make/O/N=(vLenData * vRep) wRepData
    wRepData[] = wData[floor(p / vRep)]
End


Hope this helps,
Kurt

January 4, 2016 at 03:34 am - Permalink

This is exactly what I was trying to do! thank you so much!!

I'm also trying to figure out how to tile a wave, but cannot find something that works properly... (something that would give [1,2,3,4,1,2,3,4,1,2,3,4,1,2,3,4] from [1,2,3,4]). A loop with Concatenate would work, but any idea on avoiding loops?

January 4, 2016 at 05:19 am - Permalink

This should do the trick:

Function Test()
    Make/O/N=4 data={1, 2, 3, 4}
    Rep(data, 4)
    Rep2(data, 4)
End
 
Function Rep(wData, vRep)
    wave wData
    variable vRep
    variable vLenData = DimSize(wData, 0)
    Make/O/N=(vLenData * vRep) wRepData
    wRepData[] = wData[floor(p / vRep)]
End

Function Rep2(wData, vRep)
    wave wData
    variable vRep
    variable vLenData = DimSize(wData, 0)
    Make/O/N=(vLenData * vRep) wRepData2
    wRepData2[] = wData[mod(p, vRep)]
End

January 4, 2016 at 05:29 am - Permalink

J-E Petit wrote:

Is there an inbuilt Igor equivalent for the repeat function of numpy?
for an array x=[1,2,3,4], numpy.repeat(x,4) will give [1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4]


You can use:

•make/n=4 xwave = {1,2,3,4}
•make/n=16 repeatWave = xwave[floor(p/4)]
•print xwave
  xwave[0]= {1,2,3,4}
•print repeatWave
  repeatWave[0]= {1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4}


J-E Petit wrote:

I'm also trying to figure out how to tile a wave, but cannot find something that works properly... (something that would give [1,2,3,4,1,2,3,4,1,2,3,4,1,2,3,4] from [1,2,3,4]). A loop with Concatenate would work, but any idea on avoiding loops?


Try this:
•Make/N=4 data = {1,2,3,4}
•Make/N=16 dest = data[mod(p, 4)]
•print data
  data[0]= {1,2,3,4}
•print dest
  dest[0]= {1,2,3,4,1,2,3,4,1,2,3,4,1,2,3,4}


If you haven't already, I recommend you read the following help topic:
DisplayHelpTopic "Waveform Arithmetic and Assignment"

January 4, 2016 at 06:42 am - Permalink

Using MatrixOP there is a simpler way:
Make/n=5 ddd=p
Matrixop/o aa=rowrepeat(ddd,5)
redimension/n=25 aa

January 4, 2016 at 09:25 am - Permalink