What is the test for determining whether a defendant is competent to plead guilty to a charge of assault?

The test for competency is whether the defendant has "sufficient present ability to consult with his attorney with a reasonable degree of rational understanding and has a rational as well as factual understanding of the proceedings." United States v. Chavez, 656 F.2d 515, 518 (9th Cir.1981) (citations omitted). A hearing is required when a district court "entertains, or reasonably should entertain, a [reasonable] doubt as to the defendant's ability to understand the nature and consequences of the plea, or to participate intelligently in the proceedings and to make a reasoned choice among the alternatives presented." Id. at 517.