3D Plots

For standard folios, ReliaSoft’s 3D Plot utility allows you to visualize 3-dimensional functions, such as a surface plot of the likelihood function. You can rotate the plot both vertically and horizontally to examine it from any angle.

In Weibull++, the 3D plot is a surface plot of the likelihood function. It plots the likelihood values (LK values) with respect to the estimated parameters of a distribution. The shape of the plot may help you to evaluate the amount of variability in the parameter estimates. A small surface (tall, tower-like peak) suggests that there is less uncertainty in the parameter estimates at the maximum LK value, while a large surface suggests that there is a large uncertainty in the parameter estimates. You can create a 3D plot of the likelihood function for any of the available distributions in Weibull++ except for 1-parameter Weibull, mixed Weibull, Bayesian-Weibull or Weibull using competing failure modes distribution.

To create a 3D Plot for a Weibull++ folio, choose Life Data > Analysis > 3D Plot.

In ALTA, the 3D plot provides a choice of several functions that you can plot with respect to time and stress, in addition to the likelihood function plot. This includes the pdf, failure rate, reliability and unreliability functions. The shape of the plot may help you to evaluate how the function is influenced by time and stress.

To create a 3D Plot for an ALTA folio, choose ALTA > Analysis > 3D Plot.