Plot Multiple Traces on Graph from Procedure Not Working

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Mon, 02/20/2023 - 12:10 am

Dear all,

Igor beginner here.

I've written a procedure containing a function which takes time of flight data waves "Spectrum_01, Spectrum_02 . . ." as an argument. I perform calculations on those waves to convert to kinetic energy in the procedure and eventually want to plot each of the resultant calculated waves deriving from Spectrum_01, Spectrum_02 on the same graph.

I can plot the kinetic energy wave deriving from Spectrum_01 from the procedure, however when I call the function using Spectrum_02 as the argument, the graph updates to show only the data deriving from Spectrum_02, it does not append to the graph already showing the Spectrum_01.

Probably very simple, just not getting it at the moment. 

#pragma TextEncoding = "UTF-8"
#pragma rtGlobals=3             // Use modern global access method and strict wave access
#pragma DefaultTab={3,20,4}     // Set default tab width in Igor Pro 9 and later

//constants
//--------------------------------------------------------------------------------------------------------------------------------------------------
static constant PlanckConstant = 6.62607015E-34 //units of Joule seconds
static constant speedofLight = 299792458 //units of metres per second
static constant electronMass = 9.1093837E-31 //mass of electron in kg
static constant electronCharge = 1.60217663E-19 //electron charge in C
//--------------------------------------------------------------------------------------------------------------------------------------------------

//Conversion of Time of Flight to Electron Kinetic Energy

function TOF2eKE(wave amplitude, variable DetectorPosition)

//Variable declarations (^function parameters declared in-line ^)

variable ScaleValue = 1e-09 //use this value for SetScale and for increment value in peak-finding algorithm later
variable TOFlength = ((100-DetectorPosition) + 617.22)/1000 //TOF Length in metres

//Set x-scaling and compute x values, storing them in TOF wave
//-----------------------------------------------------------------------------------------------------------------------------------------------------------------------
SetScale/P x 0, ScaleValue,"seconds", amplitude //set x-scaling such that computed x-values are in the correct increments of the digitization time bin
Duplicate /O amplitude, TOF //Duplicate amplitude wave and rename this new wave TOF; ensures dimensions are always the same
TOF = x //extract calculated x-values and reasign TOF wave with x-values

//-----------------------------------------------------------------------------------------------------------------------------------------------------------------------
//Crude Calibration Parameters (do not need to be so accurate for first iteration
//-----------------------------------------------------------------------------------------------------------------------------------------------------------------------
 
 variable TemporalOffset = 0 //temporal offset in seconds, from calibration routine
 variable CalibrationLength = TOFLength //actual electron trajectory distance from calibration routine. Should be close to physical flight tube length. In metres.
 variable EnergyOffset = 0  //Energy offset from calibration routine, in J //Changed to eV
 
//---------------------------------------------------------------------------------------------
//Calculation of the Jacobian Scaling Factor in converting from time to energy
//----------------------------------------------------------------------------------------------
 
 variable TOFlengthsquared = TOFlength^2
 Duplicate /O amplitude, Jacobian //Duplicate amplitude wave to ensure the Jacobian has correct dimensions
 Jacobian = (electronMass*TOFlengthsquared)/((TOF-TemporalOffset)^3)
 
 //---------------------------------------------------------------------------------------------
//Calculation of eKE without Jacobian Scaling Factor
//----------------------------------------------------------------------------------------------
 
 Duplicate /O TOF, eKE
 eKE = (0.5*electronMass*TOFlengthsquared)/(TOF-TemporalOffset)^2
 
//---------------------------------------------------------------------------------------------
//Calculation of eKE scaled with (corrected by) Jacobian Scaling Factor
//----------------------------------------------------------------------------------------------
string AmplitudeTraceName = NameOfWave(amplitude) +"Jacobian Scaled Amplitude"
Duplicate /O eKE, eKE_Offsetcorrected //Duplicate eKE wave for new eKE wave of same dimensions which will be corrected by energy offset, in Joules
Duplicate /O eKE, eKE_Offsetcorrected_eV //Duplicate eKE wave for new eKE wave of same dimensions which will be corrected by energy offset, in eV
Duplicate /O amplitude, JacobianScaledAmplitude //Duplicate TOF amplitude wave for new amplitude wave of same dimensions whhich will be corrected by the Jacobian
JacobianScaledAmplitude = (Jacobian)*amplitude

//---------------------------------------------------------------------------------------------
//Subtraction of any energy offset from electron kinetic energies, giving the energy offset eKE in units of eV
//----------------------------------------------------------------------------------------------

eKE_Offsetcorrected_eV = ((eKE_Offsetcorrected-EnergyOffset)/electronCharge)

//---------------------------------------------------------------------------------------------
//Plot
//----------------------------------------------------------------------------------------------

DoWindow /F /N /T electronKineticEnergy, "Electron Kinetic Energy(eV)"
Display /N=electronKineticEnergy
AppendToGraph JacobianScaledAmplitude /TN= AmplitudeTraceName vs eKE_Offsetcorrected_eV


end

 

 

I think I figured this out. 

I reconfigured the function above to return the two waves of interest:

Function eKEplot(wave amplitude, variable DetectorPosition)
    string traceName = NameofWave(amplitude)
    string AmplitudeNewName = "JacobianScaledAmplitude" + traceName
    string eKEnewName = "eKE_Offsetcorrected_eV" + traceName
    Wave JacobianScaledAmplitude, eKE_Offsetcorrected_eV
    [JacobianScaledAmplitude, eKE_Offsetcorrected_eV] = TOF2eKE(amplitude,DetectorPosition)
    Duplicate /O JacobianScaledAmplitude, $AmplitudeNewName //duplicate y wave but with individualised name to eliminate naming conflict and overwriting when function is called again
    Duplicate /O eKE_Offsetcorrected_eV, $eKEnewName //duplicate x wave but with individualised name to eliminate naming conflict and overwriting when function is called again
    DoWindow eKE //Does window named eKE exist? If it does, the implicit variable V_flag = 1; else zero
    if (V_flag == 0) //if the window does not exist . . .
        Display /N=eKE //make the window!
        AppendToGraph $AmplitudeNewName /TN= $traceName vs $eKEnewName //Plot graph using individualised names
    else
    endif
End

 

February 20, 2023 at 01:41 am - Permalink

You have taken a good step in separating the processing function from the plot function. I might go further in the way below.

Function do_analysis(...)

    // convert the wave scales
    do_conversion(...)

    // append to (new or existing) plot
    append_toplot(...)

    return 0
end

 

February 20, 2023 at 07:52 am - Permalink