XLfit

SPC for Excel pioneered accessible, affordable Statistical Process Control inside Excel, and has grown into a professional-grade solution trusted by quality practitioners worldwide. Built for quality engineers, quality managers, and Lean Six Sigma practitioners, it pairs the familiarity of Excel with the analytical depth professionals rely on every day. Trusted by 100,000+ professionals in over 80 countries since 1995. The software includes: • Process Capability Analysis — to meet customer requirements • Control Charts and Histograms — to manage and monitor processes • Gage R&R — to validate the measurement system • Problem-Solving Tools (Pareto, scatter, and more) — to support team problem-solving • Advanced Analysis (DOE, ANOVA, regression, hypothesis testing) — for advanced analytical needs A one-time, perpetual license — no annual or maintenance fees, with installation on two computers per user.

NLREG is a powerful statistical analysis program that performs linear and nonlinear regression analysis, surface and curve fitting. NLREG determines the values of parameters for an equation, whose form you specify, that cause the equation to best fit a set of data values. NLREG can handle linear, polynomial, exponential, logistic, periodic, and general nonlinear functions. Unlike many "nonlinear" regression programs that can only handle a limited set of function forms, NLREG can handle essentially any function whose form you can specify algebraically. NLREG features a full programming language with a syntax similar to C for specifying the function that is to be fitted to the data. This allows you to compute intermediate work variables, use conditionals, and even iterate in loops. With NLREG it is easy to construct piecewise functions that change form over different domains. Since the NLREG language includes arrays, you can even use tabular look-up methods to define the function.