"Extract Pulse Feature" display rounded value in legend and HDF5 export fails

[ThomasMalletCodra]

Describe the bug

Multiple issues have been identified with the "Extract pulse feature" function (extract_pulse_feature):

1. Inconsistent legend values

When running "Extract pulse feature" , the values displayed in the result legend are not consistent with the actual measured values on the curve. This appears to be a display formatting issue (Significant figure/Scientific writing).

3. HDF5 export failure

After processing the signal with "Extract pulse feature", attempting to save the file in HDF5 format fails : "cannot serialize 'step' of type"

To Reproduce

1. Open DataLab
2. Import the attached CSV signal file (extract_pulse_issue.csv)
3. Run Computing → Extract pulse feature on the imported signal
4. Observe that:
   • The legend values do not match the values visually measured on the plot
5. Attempt to save the project in HDF5 format
6. Observe the save error

Expected behavior

• The legend should display values consistent with the curve data table
• HDF5 export should succeed without errors

Screenshots

Extract pulse feature result with inconsistent legend values:

HDF5 save error:

Test data

A CSV signal file (extract_pulse_issue..csv) is attached to reproduce the issue :

extract_pulse_issue.csv

Installation information

• Reported by external user and reproduced by DataLab Platform Developers team
• Observed on standard DataLab installation

Additional context

• Affected component: Sigima (sigima.proc.signal — extract pulse feature function) and DataLab (HDF5 export)
• Related Sigima function: extract_pulse_feature in sigima/proc/signal/