anova

effect vs. predict function

跟風遠走 提交于 2021-02-07 17:32:48
问题 I'm simultaneously trying to understand R's predict() function and the 'effects' package effect() function. Essentially, I'm running a regression to test the interaction of two dichotomous IVs on a DV while controlling for two continuous covariates. In my actual dataset, the interaction is significant and so now I would like to plot the interaction. Because I have covariates in my model, I should plot the means after controlling for these other variables (i.e. estimated marginal means in SPSS

Difference in model fitness estimate between lmer() and anova() [closed]

冷暖自知 提交于 2021-02-07 09:13:05
问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 8 years ago . Improve this question I want to model the treatment effect over time on biological data using lmer() to take into account the individual effect. The procedure usually used is to build several models by deleting step by step fixed effects and interactions terms and then find the best models using anova(model1

How to conduct an ANOVA of several variables taken on individuals separated by multiple grouping variables?

ぐ巨炮叔叔 提交于 2021-01-29 08:40:27
问题 I have a data frame similar to the one created by the code below. In this example, measurements of 5 variables are taken on are 30 individuals represented by ID . The individuals can be separated by any of three grouping variables: GroupVar1,GroupVar2,GroupVar3 . For each of the grouping variables, I need to conduct an ANOVA for each of the 5 variables, and return the results of each (possibly onto a pdf or separate document?). How can I write a function, or use iteration, to handle this

One-way ANOVA for each sub-group in a melted data frame

ε祈祈猫儿з 提交于 2021-01-28 17:58:30
问题 I have a very large data set that requires individual one-way ANOVAs for multiple species on 4 different treatments with several measurements. Usually I just make separate excel spread sheets for each species and run ANOVAs on each, looping through each measurement column, but this is very time consuming. Is it possible to use a single spread sheet and run ANOVAs on the melted data? Or perhaps there is another reshape option I could use? Data: structure(list(Species = c("A", "A", "A", "A", "A

How to generate a compact letter display for pairwise TukeyHSD

时光总嘲笑我的痴心妄想 提交于 2021-01-07 03:24:52
问题 I'm having trouble generating a compact letter display for my results. I've run an ANOVA followed by Tukey's HSD to generate the p values for each pair, but I do not know how (or if it is possible?) to assign letters to these p values to show which pairs are significant from each other. csa.anova<-aov(rate~temp*light,data=csa.per.chl) summary(csa.anova) TukeyHSD(csa.anova) This runs the tests I need, but I don't know how to assign letters to each p value to show which pairs are significant.

Statsmodels Anova for logistic regression

会有一股神秘感。 提交于 2020-07-20 07:47:28
问题 I found the statsmodels implementation of the anova testing for linear models to be very useful (http://www.statsmodels.org/dev/generated/statsmodels.stats.anova.anova_lm.html#statsmodels.stats.anova.anova_lm) but I was wondering, since it's not present in the library, how one could approach building the equivalent version for the logistic regression part. formulas : from statsmodels.formula.api import ols, logit import statsmodels.api as sm ols(formula_str, data=data_on_which_to_perform

How to write a for loop which creates a model and has a function which references that same model

我的梦境 提交于 2020-05-26 09:09:25
问题 I am trying to run a post hoc analysis on an unbalanced two way anova using the anova_test funciton in the rstatix package. I need to run this post hoc test iteratively, as I have ~26 response (y) variables. My first step is to create models of all my y variables with relation to group and treatment . I have successfully managed to do this, creating a single list with 26 models: models <- map(data[,y1:y26], ~(lm(.x ~data$group*data$treatment))) Now comes the part I'm stuck on. Referring to

Unable to run Two-way repeated measures ANOVA; 0 (non-NA) cases

为君一笑 提交于 2020-05-08 14:44:17
问题 I am trying to follow the tutorial by Datanovia for Two-way repeated measures ANOVA. A quick overview of my dataset: I have measured the number of different bacterial species in 12 samplingsunits over time. I have 16 time points and 2 groups. I have organised my data as a tibble called "richness"; # A tibble: 190 x 4 id selection.group Day value <fct> <fct> <fct> <dbl> 1 KRH1 KR 2 111. 2 KRH2 KR 2 141. 3 KRH3 KR 2 110. 4 KRH1 KR 4 126 5 KRH2 KR 4 144 6 KRH3 KR 4 135. 7 KRH1 KR 6 115. 8 KRH2

How can i get the shapiro-wilk test

冷暖自知 提交于 2020-04-18 01:14:06
问题 I want to do the shapiro-wilk test for my regressions. Here is my code library(data.table) Regresiones_shapirotest_1<- data.table(tabla.Enero)[, .(Lm = lapply(.SD, function(x) resid(lm(tabla.Enero$PPNA ~ x)))), .SDcols = 15:93] I can get the test values only in the console Regresiones_shapirotest_1 [, lapply(Lm, shapiro.test)] [2] write.xlsx (Regresiones_shapirotest_1 , file = "shapirotest.xlsx", sheetName = "Hoja1", Col.names = TRUE, row.names = TRUE, append = FALSE) But when I try to export

How can i get the shapiro-wilk test

狂风中的少年 提交于 2020-04-18 01:11:32
问题 I want to do the shapiro-wilk test for my regressions. Here is my code library(data.table) Regresiones_shapirotest_1<- data.table(tabla.Enero)[, .(Lm = lapply(.SD, function(x) resid(lm(tabla.Enero$PPNA ~ x)))), .SDcols = 15:93] I can get the test values only in the console Regresiones_shapirotest_1 [, lapply(Lm, shapiro.test)] [2] write.xlsx (Regresiones_shapirotest_1 , file = "shapirotest.xlsx", sheetName = "Hoja1", Col.names = TRUE, row.names = TRUE, append = FALSE) But when I try to export