[[["容易理解","easyToUnderstand","thumb-up"],["確實解決了我的問題","solvedMyProblem","thumb-up"],["其他","otherUp","thumb-up"]],[["難以理解","hardToUnderstand","thumb-down"],["資訊或程式碼範例有誤","incorrectInformationOrSampleCode","thumb-down"],["缺少我需要的資訊/範例","missingTheInformationSamplesINeed","thumb-down"],["翻譯問題","translationIssue","thumb-down"],["其他","otherDown","thumb-down"]],["上次更新時間:2025-08-25 (世界標準時間)。"],[],[],null,["# ln\n\nThe `ln` function can be used in [custom filters](/looker/docs/filtering-and-limiting#custom-filters) and [table calculations](/looker/docs/table-calculations) to get the natural logarithm of a value.\n\nSyntax\n------\n\n**`ln(value)`**\n\nThe `ln` function takes the logarithm of a `value` to the base of the mathematical constant *e*.\n\nExamples\n--------\n\nThe `ln` function can be used to model exponential growth linearly by taking `ln` of the dependent variable. For example: \n\n ln(order_items.growth_rate)\n\nThings to know\n--------------\n\n`ln` can be used to give you the time needed to reach a certain level of growth.\nFor instance, modeling growth exponentially as:\n\n*growth = e^time^*\n\n*time* can be determined using `ln` as follows: \n\n ln(growth)"]]