> For the complete documentation index, see [llms.txt](https://docs.enercalc.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.enercalc.com/e3d-training-manual/analysis/specifiying-and-performing-the/analysis-options/specifying-convergence-control.md). # Specifying Convergence Control How to set maximum iterations and axial force tolerance to control convergence during iterative and P-Delta analyses. Convergence control is specified in the *Analysis Options* dialog, which can be opened by clicking **Analysis > Analysis Options**. When a model contains tension-only members or compression-only members, or when a P-Delta analysis is run, the analysis is an iterative process. Sometimes many iterations are required before convergence is achieved. Sometimes convergence requires too many iterations to be practical, or perhaps convergence is not even achievable. Without some control over the iteration process, this could lock up a processor in an infinite loop. To avoid long delays and infinite loops, the program offers two controls on convergence: Maximum iterations and Axial force tolerance. The Maximum iterations control allows the user to specify an overall maximum number of iterations that will be run when an analysis is performed. If convergence has been achieved before that number of iterations, the analysis stops when convergence has been reached. If convergence has not been achieved, the analysis stops when it reaches the specified maximum number of iterations. The control named Axial force tolerance between P-Delta iterations sets a threshold for the program to determine if a P-Delta analysis has converged. By comparing the maximum amount of change in the axial force in any member with this specified value, the program is able to determine if the changes are small enough to consider the analysis to have converged. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.enercalc.com/e3d-training-manual/analysis/specifiying-and-performing-the/analysis-options/specifying-convergence-control.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.