交会图的趋势成分的数据从不同的分析有效吗?- 江南体育网页版- - - - -地球科学堆江南电子竞技平台栈交换 最近30从www.hoelymoley.com 2023 - 07 - 10 - t06:01:01z //www.hoelymoley.com/feeds/question/7227 https://creativecommons.org/licenses/by-sa/4.0/rdf //www.hoelymoley.com/q/7227 7 交会图的趋势成分的数据从不同的分析有效吗? 安东尼 //www.hoelymoley.com/users/5149 2016 - 01 - 11 t16:35:39z 2016 - 02 - 12 - t05:10:54z < p >我读过一些地球化学论文包含交会图的组成组件,导致不同的岩石样本分析。举个例子,一个是体积百分比TiO 2 <子> < /订阅>和Nb的ppm (ppm)。结果从这样的情节似乎对我高度怀疑,因为这两个属性的封闭特性。但是,我不是一个地球化学家,所以我将不胜感激任何反馈的有效性结果从地球化学和数据分析两个视角来。< / p > //www.hoelymoley.com/questions/7227/-/7236 # 7236 2 Gimelist回答的交会图的趋势成分的数据从不同的分析有效吗? Gimelist //www.hoelymoley.com/users/725 2016 - 01 - 13 t04:16:42z 2016 - 01 - 13 t04:16:42z < p >问题是不完全清楚。你问不同的方法用来分析岩石,或者你问使用封闭(又名成分)数据在一个二元的阴谋?< / p > < p > < >强使用不同方法< /强> < / p > < p >这是很好,只要这两种方法都是准确的。例如,您可以分析一种矿物为主要元素(例如TiO <子> 2 < /订阅>)使用电子探针,然后使用微量元素(例如Nb)的介绍。如果方法正确标准化和所有可能的干扰都照顾没有理由分析不应该一起使用。如果没有正确地执行分析,我不会相信即使一个,不管它是否用于数据库与数据使用不同的方法获得。< / p > < p > <强>关闭数据< /强> < / p > < p >关闭数据意味着它必须和1或100%,这可能导致相关性并不意味着什么。一个简单的例子是一个采用vs FeO说情节在橄榄石。当然会有负相关。这种类型的情节会明显,不会告诉我们一件事情。然而,在更加复杂的情况下,这就变成了越来越多的一个问题。这主要取决于案例的基础。 Note that if you're comparing a major element (TiO2) with a trace element (Nb), there is less of a problem. The trace element is not one of the components that hardly has any implications for the close problem. Whether you have 10, 20 or 100 ppm Nb will not change anything for the 5% of TiO2 you got in your rock.

Classic statistics done on compositional data is almost always wrong. In the past 20 years or so, a new statistical field called "compositional data analysis" has emerged to solve some of the problems arising from the closure problem. In short, it means that you have to transform all of your data to log-ratio form, do your stats, and transform it back. This can't solve all of the problems, however.

Now, the question is - do we care that it's wrong? In the vast majority of papers, there is hardly any statistics done of compositional data, and many correlations and trends are eyeballed and drawn by hand. Often, the hassle of doing statistics the correct way does not actually contribute everything. I've heard senior petrologists claim more than once that "if it looks like a line, it is a line. If it doesn't, then it is not a line. I don't need the R2 and p-values for that".
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