What is LogXact® for?

Cytel, the acknowledged leader in exact statistical methods, helped pioneer exact methods for binary logistic regression and multinomial regression. First introduced in 1987, LogXact is unequivocally the fastest and most powerful logistic regression analysis software available today.

Why is it important?

Even with small sample sizes and missing data, LogXact® users enjoy complete confidence in their logistic regression analyses.

LogXact is the only logistic regression tool to provide these major logistic regression modeling developments:

• Only in LogXact, Firth's Penalized Maximum Likelihood Estimate (Biometrika [1993], 80, 1, pp27 - 38) (PMLE) corrects for separation bias, while exhibiting lower mean square error than usual Maximum Likelihood (ML) estimations example
• Fitting GLM in the presence of missing categorical covariates. With missing discrete covariates, LogXact employs Chen and Ibrahim's EM algorithm to produce GLM parameter estimates for the covariates. Logit, Probit, CLogLog, Poisson and Normal links are all supported

What's new in the latest version?

Profile Likelihood Based Confidence Intervals

One of the most recent LogXact procedures is Profile Likelihood Confidence Intervals for parameters of binary logistic regression. Users can also choose whether or not to apply Firth correction - see Penalized Maximum Likelihood Method (PMLE) application of Firth's method in practice.

This new procedure obtains the Profile Likelihood based confidence intervals for the parameters using the algorithm of Venzon and Moolgavkar (1988).

SAS® and LogXact® PROCs - A Powerful Combination

Now you can access the leading logistic regression analysis package while working in SAS. LogXact PROCs resides within the SAS environment, offering SAS users LogXact's modeling tools without opening another application.

LogXact PROCs' in-depth SAS integration works wonders for practicing statisticians. Often required in regulatory submission, LogXact PROCs can be called through a batch file and documented.

Engage LogXac PROCs "automatic pilot" function to distinguish large data sets from small sets, then apply the appropriate exact tests to keep your batch jobs running smoothly.

Learn More

Consult LogXact examples using real-world data sets, or download the LogXact brochure

Questions?

Call Connor Tubridy at +1.617.528.7121 or email sales@cytel.com

NOTE: StatXac®t 8 and the latest LogXact® now feature the complete user manual online in the software.

To purchase a printed manual please contact Connor Tubridy at +1.617.528.7121 or email sales@cytel.com.