Statistical Analysis Stack Exchange
Statistical Analysis Stack Exchange

Questions tagged [chemistry]

27 questions
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When if ever is a median statistic a sufficient statistic?

I came across a casual remark on The Chemical Statistician that a sample median could often be a choice for a sufficient statistic but, besides the obvious case of one or two observations where it equals the sample mean, I cannot think of another…
Xi'an
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How to predict a binary outcome with unbalanced repeated measures data?

I’m somewhat lost as to how to approach a problem I have and was hoping someone can suggest the most appropriate method. The problem: I have a data set consisting of concentration values for 8 molecules. These are measured on approx. 230 samples…
ric
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How do I record randomly assigned data succinctly in a table

Please forgive me if I am posting this in the wrong forum. Here is the context of my question: I am conducting a drug trial, of sorts. I have 7-8 potential candidates for the treatment. Between each drug administration, there has to be a…
Rushi
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How to estimate the uncertainty of a function that has to be solved numerically

Consider I have a function: $PV_m^3 - PbV_m^2 +aV_m+ab=RT$ In this example I have measured the uncertainties in $P$ and $T$ experimentally and the errors in $a$ and $b$ can be assumed to be zero. How would I go about estimating the error in…
tionichm
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can the parameters of this nonlinear equation be reliably estimated using a limited set of experimental data?

A chemical system at equilibrium is described by this equation: $$ D_{tot} = D + D \cdot \frac {P \cdot X}{D+K_P} + D \cdot \frac {E}{D+K_E} $$ The only parameters that the experimenter can control (by setting up the experiment with different…
user6376297
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Intersections of chemistry and statistics

I am asking this question for a friend who knows a lot of chemistry and is now studying statistics, primarily since he heard this is the age of data and one should know statistics. However, he is interested to know if there are works on the…
Landon Carter
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Dimensions of clustering results

My PhD research (computational organic chemistry) often generates large data sets (>10000 entires) of 'conformers' - where a conformer is basically the spatial arrangement of atoms in space. From 10000 conformers, there are generally around 10…
James
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Compare two samples?

Similar questions have been asked but have not managed to get a conclusion from them. I am comparing two sets of samples, where ratios have been obtained for several analytes per sample. So the values are restricted to be in the [0,1] interval. One…
David
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Determining whether new data is "in distribution" with training data

I'm hoping to use machine learning to predict chemical properties of various molecules. Many chemistry machine learning research papers that I come across talk about model generalizability issues related to new molecules that are not…
Ryan Zotti
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Function to fit acid reaction curve

Data in the image below shows a variable DME reacting to the increase in acid concentration. It looks like it has a very fast increase from when the concentration is raised from 0 to 0.5 and then a rapid diminishing return. I thought that a base 10…
Deathkill14
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Adjacency matrix of amino-acid residue

How to get the mathematical representation of the chemical bonds in protein residue or the whole protein? Is it possible to get the connectivity matrix or a pairwise description? The example in the photo: PyRosetta Manual, page 16. The full atom…
Pol Bel
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Correlation between chemical analysis results

I have performed chemical analysis on a sample and the resulting data is something like this: "Carbon: 1.2%, Iron: 50%, Vanadium 2.3% ..." and so on. I have 25 sets of similar data taken from other samples and I need to figure out which of these 25…
WarraChe
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Is it possible to use PCA twice, first on several subsets of data, and then again on the main components of those subsets?

I am interested in understanding if it is possible to use PCA twice, first on several subsets of data, and then again on the main components of those data subsets. I'm not entirely sure if this will give me the answer I am looking for. For example:…
Syd26S
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Choice of statistical test - confirmation

I want to know if I'm choosing the right statistical test for my situation. Description: In a production process there are several places where wastewater is created (lets call these "spots", spot 1,2 and 3). At every spot 1 sample of water is taken…
Olivier_s_j
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Graph Classification via Random Forest

This is my first post here, just a brief presentation: my name is Gianmarco, I’m Medicinal Chemistry undergraduate student who is preparing his dissertation, my idea would be to create a classifier that can distinguish anticancer drugs as active or…
Gianmarco Luchetti
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