How to Import Data into SciDAVis (ASCII, CSV, Excel)
Everything in SciDAVis starts with a table: the column-based spreadsheet window where X and Y data live before they are plotted, fitted, or analyzed. You can type values by hand, compute them with formulas — but most real work starts by importing a file. This guide covers the File → Import Ascii dialog in detail, plus the Excel workflow and fixes for the three most common import failures.
Version note: written for v2.9.x. The prebuilt binaries on SourceForge are 2.8; the import dialog is identical in both, so everything below applies either way.
Step 1 — Open the Import Ascii dialog
Go to File → Import Ascii (the command is named Import Ascii in the File menu). A file chooser appears first; select one or more data files, then the Import Ascii dialog opens. Each file you selected becomes a new table in your project, with the filename as the table name.
SciDAVis is a plain-text importer: it reads ASCII/CSV/TSV files. If your data lives in an Excel workbook (.xls/.xlsx), there is no native Excel import — save the sheet as CSV from Excel or LibreOffice first (File → Save As → CSV), then import that. One sheet per CSV; one CSV per table.
Step 2 — Choose the column separator
The most important control in the dialog is the separator setting. It must match how your file actually separates columns:
| File looks like | Choose |
|---|---|
Values separated by commas: 1.2, 3.4, 5.6 | Comma |
Values separated by semicolons: 1,2; 3,4; 5,6 (European CSV) | Semicolon |
| Values separated by tabs (copied from a spreadsheet) | Tab (the default) |
| Values separated by spaces | Space |
| Anything else | Custom character |
Symptom of a wrong choice: all your data lands in a single column. If that happens, don’t retype anything — close the table without saving it, re-import, and try the next separator.
Step 3 — Skip header lines and name the columns
Real-world data files start with comments or a header row. The dialog lets you:
- Ignore a number of lines at the top — set this to the count of comment/metadata lines so they don’t become data rows.
- Use the first non-ignored line as column names (the rename columns option) — turn this on when your file has a header row like
time, voltage, current. Column names make later plotting much easier, because plot dialogs list columns by name.
A subtlety: some files mix headers between data blocks (common in instrument exports). SciDAVis expects one continuous data block — split such files into separate files before importing.
Step 4 — Get the numbers parsed correctly
Two options control how text becomes numbers:
- Convert to numeric / locale: the dialog follows your numeric locale for the decimal separator. If your file uses a decimal comma (
3,14) while your system locale expects a period, the values import as text. Either match the locale setting in the dialog to the file, or normalize the file first. - Strip / simplify spaces: enable these when values are padded with extra whitespace — common in fixed-width exports.
After import, check the column headers: numeric columns and text columns show different type icons. If a column of numbers shows up as text, the locale/separator guess was wrong — re-import rather than converting by hand.
Step 5 — Verify the table and set the X column
- Scroll through the table. Row count should match your file (minus skipped lines).
- Decide which column is X. Right-click its header and choose Set as → X. Everything to the right of an X column is treated as Y by default; a second X column starts a second Y group (shown as
[Y2]). - Plot a quick sanity check: select the columns, then use the Plot menu (e.g. Line or Scatter) and confirm the curve looks like your data.
Troubleshooting: three classic failures
| Symptom | Likely cause | Fix |
|---|---|---|
| Everything in one column | Wrong separator | Re-import with the correct separator (Step 2) |
| Numbers imported as text (can’t plot/fit) | Decimal comma vs. period mismatch, or stray characters | Match the numeric locale in the dialog; clean non-numeric tokens from the file |
| Garbage first rows / shifted columns | Header or comment lines not skipped | Increase “ignore lines at top”; enable header-as-names if present |
Bonus: importing from a Python script
If you import the same kind of file repeatedly, script it. With Python scripting enabled (see our Python scripting guide), a table object exposes the same options as the dialog:
t = table("Table1")
t.importASCII("/path/to/data.csv", sep=",", ignore=1, renameCols=True)
t.notifyChanges()The sep, ignore, and renameCols arguments mirror the dialog’s separator, skipped-lines, and header-as-names settings.
Next steps
- Data imported? Learn to fit models to it with the Fit Wizard.
- Want several datasets in one figure? See multi-layer graphs.
- Ready to publish? Read exporting publication-quality figures.
- Need the program itself? It’s on the download page.