PRACTICAL GUIDE
Prepare spreadsheet data for charts
Prepare spreadsheet headers, decimal separators, dates and missing values before making a chart or map in Datamon.
One header row, one observation per row
Give each column a clear name and use a consistent unit. Remove merged cells, decorative title rows and subtotal rows from the data region. Keep totals separately when they would double-count the observations.
Set the decimal separator before interpreting values
100,344 can mean 100.344 with a decimal comma or 100344 with a thousands separator. In Data, confirm the detected number format and choose decimal comma or decimal point explicitly when the source is ambiguous. Compare a few known cells with the original spreadsheet before continuing.
Make dates consistent
A value such as 04/01/21 is ambiguous without a day/month convention. Review the detected date order and confirm it against an unambiguous observation. Prefer YYYY-MM-DD when preparing a new file. Sort time-series observations chronologically.
Keep missing distinct from zero
A blank cell means unknown unless your source says otherwise. A recorded zero is a measured value. Keep gaps, remove incomplete observations transparently, or estimate only with a stated method. Never fill blanks solely to make a smoother chart.
Check geographic identifiers
Region names should match the chosen administrative level. A city and a province with similar names are not interchangeable. For point data, check coordinate order and valid latitude/longitude ranges. Review unmatched records rather than accepting guessed locations.
Keep the source and an original copy
Retain the original file before cleaning or estimating values. Add the source, period, unit and any transformations to the chart description. Browser projects stay on this device until you explicitly share or upload them.