creating wave

Function/WAVE MatrixChoiceX()
    string chosenxmatrix
    Prompt chosenxmatrix, "Name of the X Matrix: ",popup,wavelist("*",";","DIMS:1")
    Doprompt  "Choose the wave:", chosenxmatrix
    wave resultx = $chosenxmatrix
    return resultx
End
Function/WAVE MatrixChoiceY()
    string chosenymatrix
    Prompt chosenymatrix, "Name of the Y Matrix: ",popup,wavelist("*",";","DIMS:1")
    Doprompt "Choose the wave:", chosenymatrix
    wave resulty = $chosenymatrix
    return resulty
End
Function trapezoidalpeakarea(a,b)
    variable a,b   //inputted bounds given by the user
    wave xdata = MatrixChoiceX()
        wave ydata = MatrixChoiceY()
    Prompt a, "Lower bound of the peak:"
    Prompt b, "Upper bound of the peak:"
    DoPrompt "Select the waves and set the upper and lower bounds of peak region", a,b
    variable result = 0
    variable i
    for (i=a; i <= (b-1); i += 1)
        result = result + (xdata[i+1]-xdata[(i)])*((ydata[i]+ydata[(i+1)])/2)
    endfor
    return result
End

Function trapezoidalpeakarea(a,b)
    variable a,b   //inputted bounds given by the user
    wave xdata = MatrixChoiceX()
        wave ydata = MatrixChoiceY()
    Prompt a, "Lower bound of the peak:"
    Prompt b, "Upper bound of the peak:"
    DoPrompt "Set the upper and lower x bounds of peak region", a,b
    variable result = areaxy(xdata, ydata, a,b)
    return result
End

#include <AreaXYBetweenCursors>