What is the test for substituting the judgment of a judge in a motion to appeal?

appellate tribunal is neither authorized nor warranted in substituting its judgment for the judgment of the trial judge." [Citations.] In the absence of a clear showing that its decision was arbitrary or irrational, a trial court should be presumed to have acted to achieve legitimate objectives and, accordingly, its discretionary determinations ought not be set aside on review. [Citations.] "Further, to be entitled to relief on appeal from an alleged abuse of discretion, it must clearly appear the resulting injury is sufficiently grave to manifest a miscarriage of justice. [Citation.]"' (People v. Preyer (1985) 164 Cal.App.3d 568, 573-574.)" (People v. Zaring (1992) 8 Cal.App.4th 362, 378.)