Removing negative data

ddsavard

Hi guys. Is there a code to remove negative value? I wish I could replace negative data by a flexible number (0, or else) and being able to replace at all step (Input, Intermediate and Output). Many thanks.

Joe

Hi Dany,

Thanks for posting this here. I wrote up a note to go into more detail, but the gist of it is as follows:

for c in data.timeSeriesList(data.Input):
    c.data()[c.data() < 0] = 0

data.updateResults()
data.emitDataChanged()
data.activeSelectionGroup().changed.emit()

The first two lines replace all the data for all input channels where it is less than 0 with 0. To do the replacement for all channels you could just omit the data.Input parameter. The last three lines are just to let various parts of iolite know that the data has changed.

All the best,

ddsavard

Thanks Joe

So this is a Python code that we need to run after the data are loaded, and it will only apply on "raw" data, right? I'm far for being confortable with Python, so what do you mean by "omit data input"? Can you send a code that will do the replacement for all channels please? So for the calculated data that would be negative, the tool at the export data windows to replace the data that are below LoD should be use, which would obliviously include the negative, right? Thank you!

Bence

Just to follow up on this for others reading this thread:

Dany asked

[The code above] will only apply the correction to raw data, right?

Yes, those lines of code will change your input data (i.e. the raw data read from your files). In general, iolite never alters the data read in from external sources, as you would have to reload the data to undo this change.

What do you mean by "omit data input"?

By this, Joe means that if you were to write the first line of code like this:

for c in data.timeSeriesList():

that is, omitting the data.Input in the brackets, it would act on all channels (Input, Intermediate and Output).

So for the calculated data that would be negative, the tool at the export data windows to replace the data that are below LoD should be use, which would obliviously include the negative, right?

Yes, you can use the "Report results below LOD" option to replace negative values in your export.

I hope that helps anyone coming to this thread in the future.