Home / Monte Carlo / Analyzing the Model / Latitude Plot

Latitude Plot¶

From Excel click...

QXL Monte Carlo New > Monte Carlo > Contribution Tools > Latitude Plot

Draws one chart for each selected pair of inputs, showing where in that pair's space the outputs stay inside their specification limits.

Select the inputs to plot and give each a low, a high and a nominal. Every pair of the selected inputs becomes one chart.

What is on a chart¶

Up to three things, two of which you can turn off:

The specification contours. The boundary in that pair's space where an output reaches a specification limit. This is the plot itself and is always drawn.

The dots, controlled by Display Dots. Points across the pair's space, showing pass or fail at each.

The Expected Variation Region, controlled by Display Expected Variation Region. A region covering the stated proportion of the joint variation of that pair, at the Confidence Interval you set.

The inputs you do not select¶

Every unselected input is held at a single value on every chart. That value is the engine's nominal for it, the same value the Surface and Contour Plot holds an unswept input at, so the two tools cannot disagree about it.

Where the numbers in the dialog come from¶

The suggested nominal, the default sweep range and whether an input can vary at all are read from the engine before any plot is built, so the numbers the dialog shows and the ranges the plot sweeps cannot differ.

What this page does not describe¶

How the plot is computed is not documented, deliberately. This page and its Options page say what the tool draws and what every control means. They do not describe the method behind it.

Options, for every control and the rules on each box.
Surface and Contour Plot, which also works pair by pair but plots the output's value rather than where it stays in specification.