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Questions - sample-size

How to find non-NA values (sample size) of a large data frame?

I have a large data frame that contains lots of NAs. The rows are soil samples from different plots, and the columns are chemical variables. I wanted to create a column or data frame with the sample s...
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user18633784

r

na

sample-size

Votes: 0

Answers: 1

Latest Answer

This will give you the NAs per column in your_dataframe library(dplyr) library(purrr) your_dataframe %>% map_df(~sum(is.na(.)))
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TarJae

changing null hypothesis value for sample size calculation of a single AUC

I am trying to get the sample size for a single AUC using power.roc.test in the pROC package. For example, the expected AUC is 0.97 (alternative hypothesis) and the value I am comparing to is 0.95 (nu...
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slee

r

roc

auc

sample-size

Votes: 0

Answers: 2

Latest Answer

I have the exact same question. It is possible to compute a sample size using with two roc objects with power.roc.test(), e.g. power.roc.test(roc1, roc2, power = 0.8) although I want to compute a sam...
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Wombat

Using second axis to display sample size for grouped data. Can't get spacing right so dot plot aligns with grouped bars in base R

I have grouped data, where every one of the bars has a different sample size, ranging from 0 samples to >600. I would like to have 2 more panels of this same graph for different data, and that woul...
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Erin

r

bar-chart

sample-size

Votes: 0

Answers: 1

Latest Answer

I think that given your setup, your vents should maybe look more like this: verts <- NULL k <- 1 for(i in 1:22){ x <- c(.375, .375+.75) verts <- c(verts, k+x) k <- max(verts) + .3...
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DaveArmstrong

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