Adding DC to a DRS

VitorBarrote

Hey friends,

I am trying to add DC to a v4 DRS and the only lines I have found that are accessible are from the U-Pb example from GitHub.
This is only the start of a series of errors I'm running into, but I think best to tackle step-by-step.

How do you get the beamsecond to latter do the dc correction?
I tried the
drs.createBeamSecondsFromLaserLog() beamSeconds = data.timeSeries('BeamSeconds').data()
form the example, but I got

File "<string>", line 58
drs.createBeamSecondsFromCutoff()
^
IndentationError: unindent does not match any outer indentation level
Traceback (most recent call last):
File "<string>", line 1, in <module>
IndexError: list index out of range

On the same note, how to I make it selectable, such as the current U-PB DRS we use.

Thank for the help! Stay tuned for many more questions 😄

Joe

Hi Vitor,

Python is very particular about indentation. You can use spaces or you can use tabs, but you must use them consistently. Indentation is important because it tells python which lines of code belong together. For example...

if condition:
    doThis()
    thenDoThat()

has a different meaning than:

if condition:
    doThis()
thenDoThat()

In the first instance, doThis and thenDoThat are called only if the condition is True, but in the second thenDoThat will be called even if the condition is False.

If I were to use spaces for the doThis() line but a tab for the thenDoThat() line (or a different number of spaces) the python interpreter would not know what to do. So, bottom line: indentation is important and must be used consistently. Since tabs and spaces look the same, you may need to use the arrow keys to move around through the code to see if the indentation white space is traversed in multiple small steps (spaces) or larger jumps (tabs).

To make a python-based DRS available in the user interface, you can simply copy it to the data reduction schemes path, which can be found by going to Preferences->Paths:

All the best,

VitorBarrote

Hey Joe, thanks for your reply. I'll check again the indentation, but what I meant with selectable is being able to choose the beamseconds between the different methods as a selectable feature in the DRS user interface. Cheers

Also, how to I attach an image here?

Joe

VitorBarrote

To create a user interface element that allows someone to switch between different beam seconds methods you need to use our python interface to Qt widgets. That documentation is for C++, but what is available and the parameters required, etc. are very similar for Python. For example, you could create a QComboBox with the options as follows:

# Import the relevant widget
from iolite.QtGui import QComboBox

# Assuming you already have your main settings widget called 'widget', 
# create the QComboBox with 'widget' as its parent
bsMethodComboBox = QComboBox(widget)

# Next you can add some items
bsMethodComboBox.addItems(['Laser log', 'Gaps between samples', 'Cutoff threshold'])

# And then add it to a layout. There are a lot of ways you might do this and how you do it
# will depend on the type of layout you have set for 'widget'. I'm going to assume there is 
# a QFormLayout set for 'widget', so then we could do
widget.layout().addRow('Beam seconds method', bsMethodComboBox)

# Finally, we need a way to update the stored settings when the user changes that control
bsMethodComboBox.activated.connect(lambda v: drs.setSetting('BeamSecondsMethod', bsMethodComboBox.currentText))

Now when when the runDRS function is called you could get the stored setting and do the appropriate calculation

method = drs.setting('BeamSecondsMethod')
if 'log' in method:
    drs.createBeamSecondsFromLaserLog()
elif 'samples' in method:
    drs.createBeamSecondsFromSamples()
# and so on...

Here is an example DRS that only does beam seconds...

# A python-based data reduction scheme for iolite 4 starts with some metadata
#/ Type: DRS
#/ Name: Beam Seconds
#/ Authors: Joe
#/ Description: Calculates beam seconds
#/ References:
#/ Version: 0
#/ Contact: joe@iolite-software.com


from iolite.QtGui import QWidget, QComboBox, QFormLayout, QLineEdit

def runDRS():
    drs.message('Calculating beam seconds...')
    drs.progress(0)

    # Get settings
    method = drs.setting('BeamSecondsMethod')
    print(f'Using beam seconds method {method}')

    try:
        channel = data.timeSeries(drs.setting('BeamSecondsChannel'))
        value = float(drs.setting('BeamSecondsValue'))
    except Exception as e:
        if 'threshold' in method or 'change' in method:
            raise Exception(e.what())
        else:
            pass

    if 'log' in method:
        drs.createBeamSecondsFromLaserLog()
    elif 'samples' in method:
        drs.createBeamSecondsFromSamples()
    elif 'threshold' in method:
        drs.createBeamSecondsFromCutoff(channel, value)
    elif 'change' in method:
        drs.createBeamSecondsFromJump(channel, value)

    drs.message('Finished!')
    drs.progress(100)
    drs.finished()


def settingsWidget():
    widget = QWidget()
    formLayout = QFormLayout()
    widget.setLayout(formLayout)

    bsMethodComboBox = QComboBox(widget)
    bsMethodComboBox.addItems(['Laser log', 'Gaps between samples', 'Cutoff threshold', 'Rate of change'])
    bsMethodComboBox.activated.connect(lambda v: drs.setSetting('BeamSecondsMethod', bsMethodComboBox.currentText))
    bsMethodComboBox.setCurrentText(drs.setting('BeamSecondsMethod'))
    formLayout.addRow('Beam seconds method', bsMethodComboBox)

    # Also need controls to select which channel/value for threshold or rate
    bsChannelComboBox = QComboBox(widget)
    bsChannelComboBox.addItems(data.timeSeriesNames(data.Input))
    bsChannelComboBox.activated.connect(lambda v: drs.setSetting('BeamSecondsChannel', bsChannelComboBox.currentText))
    bsChannelComboBox.setCurrentText(drs.setting('BeamSecondsChannel'))
    formLayout.addRow('Beam seconds channel', bsChannelComboBox)

    bsValueLineEdit = QLineEdit(widget)
    bsValueLineEdit.textEdited.connect(lambda v: drs.setSetting('BeamSecondsValue', float(bsValueLineEdit.text)))
    bsValueLineEdit.setText(drs.setting('BeamSecondsValue'))
    formLayout.addRow('Beam seconds value', bsValueLineEdit)

    drs.setSettingsWidget(widget)

The way you were trying to get the beam seconds that you originally posted looked correct to me, so I think it is just a matter of fixing the indentation (and adding the UI elements, if you want to be able to configure it).

An example of actually doing a down-hole correction using the beam seconds can be found in the U-Pb example. Of particular interest are lines 26-27 (form of function to fit) and lines 126-141 (compiling down-hole data, removing null values, performing the fit, and creating the corrected channel).

I'll make a separate post with instructions on how to upload images.

All the best,

VitorBarrote

Hey Joe, thanks for your help, I managed to add the widget but I have no idea if it works yet. But it should. The reason for that is because I can't get the DH to work. Even by just trying to run your example I run into this issue:

"There was an error in your python runDRS function:
<class 'TypeError'>: Improper input: N=4 must not exceed M=0
File ""C:/source/U-Pb example.py"", line 172, in runDRS
processRatio(ratio)
"

VitorBarrote

I'm also getting an error in the line
if 'threshold' in method or 'change' in method: raise Exception(e.what())

<class 'TypeError'>: argument of type 'NoneType' is not iterable

Joe

VitorBarrote

I just ran our U-Pb example without any problems here. I'll need to see your complete python file to help. Can you please post it here or send it to support@iolite-software.com. If you're posting code, it is helpful to wrap it in "code" tags by clicking the </> button in the editor toolbar.

Thanks!