XYZ Two independent variables

TableCurve 3D

When the response depends on two things at once, a curve will not tell you about it. TableCurve 3D fits more than 38,000 surface equations to your XYZ data and ranks them the same way the 2D engine ranks curves — then lets you turn the surface around and look at it from any angle.

Fitted response surface, two modes 20 × 20 grid
What it does

38,000 surfaces, sorted for you

Surface fitting is where guessing a model breaks down completely. The interaction between two variables rarely looks like anything you would nominate by eye, and the difference between a saddle, a ridge and two separate modes is not something a contour plot settles. So the engine fits the library and lets the statistics argue.

Ranked surface fits

The full surface library is fitted and scored on r², adjusted r², the F-statistic and standard error, exactly as in the 2D engine.

Contours and projections

Every fitted surface comes with contour and density views. Reading level curves is often how a mechanism becomes obvious.

Rotate and animate

Spin the surface live to check whether a feature is real structure or an artefact of the viewing angle, and record the rotation for a presentation.

Gridding for scattered data

Real measurements rarely land on a neat lattice. Scattered XYZ points are gridded before fitting so irregular sampling is not a barrier.

Your own surfaces

Enter a function of x and y in algebraic notation and it is fitted and ranked beside the built-in library.

Publication output

Surfaces, contours, coefficient tables and the statistical summary export to Word and Excel at presentation resolution.

From the program

Surfaces drawn by the fitting engine

Captures from TableCurve 9 itself. Shading, mesh density, view angle, backplanes and contour overlays are all set from the panel beside the graph.

The 3D View Options window showing a fitted two-mode surface in blue-to-green gradient shading with the measured data points marked on it, at a 210 degree XY angle and 10 degree Z angle
Fitted surface with measured points 50 × 50 mesh, blue-green gradient, XY angle 210° and Z angle 10°
TableCurve 9 main window: project tree on the left, grouped toolbars across the top, and a fitted thermal-conductivity surface over temperature and pressure
In the main window Thermal conductivity against temperature and pressure, with the source summary below
How a surface fit runs

Four steps from scattered points to a surface

  1. Bring in XYZ

    Three columns, however they were sampled. Paste, open a file, or type them in.

  2. Grid and fit

    Scattered points are gridded, then the selected surface families are fitted and scored.

  3. Look from every angle

    Rotate the ranked surfaces, switch to contours, and check the residuals across the plane.

  4. Take the model out

    Export the surface, the contour map, the coefficients or generated source code.

Specification

What is in the box

TableCurve 3D is the XYZ half of the TableCurve 9 program. It installs and licenses on its own, and upgrades to Studio by changing the licence key rather than the installation.

A 3D licence can open and view 2D functions, but curve fitting requires TableCurve 2D or Studio.

Data model
XYZ triples, two independent variables
Equations
38,000+ built-in surfaces, plus user-defined functions
Preprocessing
Gridding and smoothing for scattered or irregular sampling
Precision
128-bit extended-precision solver for ill-conditioned fits
Statistics
r², adjusted r², F-statistic, standard error, coefficient confidence intervals
AI guidance
Copy for Claude.ai — hands over the equation, statistics and residuals
Graphics
Rotatable surfaces, contour and density maps, residual surfaces
Export
Word, Excel, clipboard, generated source code
Platform
Windows 10 and 11, 64-bit
Licensing
Annual or perpetual, academic or commercial

Find out what your second variable is doing

The trial fits the full surface library. Load the experiment you have been treating as two separate curves and see what it looks like as one surface.