Rose Diagram Maker for Geology, Free Online
Paste a column of azimuths (strikes, joint trends, palaeocurrents) and get a rose diagram with your choice of bin width and mirrored or one-way petals. Free, with vector SVG export.
What a rose diagram shows
A rose diagram is a histogram bent into a circle. Azimuths are grouped into bins — 10° or 15° is typical — and each bin is drawn as a petal whose length reflects how many measurements fell into it. It is the natural way to display directional data, because a linear histogram breaks at 360°/0° and splits a north-trending population in half.
The single most important setting is whether your data are bidirectional or unidirectional. Joints, veins, lineaments, fold axial traces and fracture traces have no sense of direction: a 040° joint is the same joint as a 220° one, so the diagram should be symmetric and the data mirrored. Paleocurrent indicators, glacial striae with a known ice-flow sense, and wind measurements *do* have a direction, and mirroring them would be wrong.
Data
Paste straight from Excel or Google Sheets, or import a CSV or .xlsx file — columns are matched by name, in any order, and a workbook can bring one specimen per sheet.
| # | Azimuth° | Set(opt) | Label(opt) | |
|---|---|---|---|---|
| 1 | ||||
| 2 | ||||
| 3 | ||||
| 4 |
0 rows of data
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Enter data on the left to plot it
SVG is vector — resize it in Illustrator or Inkscape without losing quality. PNG 4× is roughly 600 dpi at figure width.
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Options
This plot has no adjustable options yet.
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The petal-length trap
Because the area of a petal grows with the square of its radius, plotting raw counts as radius makes a large bin look far more dominant than it is. Scaling petal radius by the square root of the count makes petal area proportional to frequency, which is what the eye actually reads. If you are comparing two roses in the same figure, make sure they share a scale as well.
Who uses one
Structural geologists summarising joint and fracture sets. Sedimentologists reconstructing paleocurrent directions from cross-bedding, flute casts and imbrication. Geomorphologists and remote-sensing analysts characterising lineament trends. Coastal and wind engineers, and planetary scientists mapping graben orientations.
Common questions
- What bin width should I choose?
- Ten degrees is the usual default. With fewer than about 30 measurements go wider (15–20°) so the diagram is not dominated by noise; with several hundred you can go to 5° and still see real structure.
- Can I weight measurements?
- Yes — supply an optional weight column, for example fracture trace length or aperture, and petals are scaled by the summed weight rather than the raw count.
- Can I collect azimuths in the field and finish the diagram in the office?
- Yes. Enter the azimuths on a phone at the outcrop, then use “Send to device” to turn the table into a QR code and a link. Scan it from the desktop and the same column of readings opens there, with your bin width and mirroring settings already applied. The data rides in the fragment of the URL — the part after the “#” — which is never sent to a server, so a lineament survey over a client’s licence area does not pass through anybody else’s system on the way to your report. Creating the link needs Pro; opening one does not.
Methodology
A methods paragraph to put beside the exported figure. It describes the tool’s default settings, so edit a clause if you changed one. References are given as the tool’s source code records them.
Azimuths were grouped into 10° sectors and drawn as a rose diagram in StrataPlot, with petal radius proportional to the square root of the sector count so that petal area, not length, represents frequency. The mean direction and circular standard deviation were computed from the resultant of unit vectors; for axial data each reading was also counted in the opposite sector, and angles were doubled before averaging and the mean halved back into 0–180°.
References
- StrataPlot. (2026). StrataPlot: Rose Diagram [Computer software]. https://www.strataplot.com/rose-diagram
The code behind this tool names no published source for its method, so none is listed beyond the tool itself.
How to cite this tool
If a figure made here goes into a report, thesis or paper, cite the tool so readers know how it was drawn. Add the date you accessed it if your style guide asks for one.
StrataPlot. (2026). StrataPlot: Rose Diagram [Computer software]. https://www.strataplot.com/rose-diagram
@misc{strataplot_rosediagram,
author = {{StrataPlot}},
title = {StrataPlot: Rose Diagram},
year = {2026},
howpublished = {\url{https://www.strataplot.com/rose-diagram}},
note = {Computer software}
}