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##This R markdown file, written by Savanna van Mesdag, details t-tests and Wilcoxon #Rank Sum tests carried out on substrate data collected on the Barrow-in-Furness slag #bank in 2021, to test for differnces between capped and uncapped (exposed slag) substrates.
#First to install the relevant packagesā¦
#install.packages("tidyverse")
#install.packages("rstatix")
#install.packages("ggpubr")
#Then to load the packagesā¦
library(tidyverse)
## Warning: package 'tidyverse' was built under R version 4.4.1
## Warning: package 'tidyr' was built under R version 4.4.1
## Warning: package 'readr' was built under R version 4.4.1
## Warning: package 'purrr' was built under R version 4.4.1
## Warning: package 'forcats' was built under R version 4.4.1
## Warning: package 'lubridate' was built under R version 4.4.1
## āā Attaching core tidyverse packages āāāāāāāāāāāāāāāāāāāāāāāā tidyverse 2.0.0 āā
## ā dplyr 1.1.4 ā readr 2.1.5
## ā forcats 1.0.0 ā stringr 1.5.1
## ā ggplot2 3.5.1 ā tibble 3.2.1
## ā lubridate 1.9.3 ā tidyr 1.3.1
## ā purrr 1.0.2
## āā Conflicts āāāāāāāāāāāāāāāāāāāāāāāāāāāāāāāāāāāāāāāāāā tidyverse_conflicts() āā
## ā dplyr::filter() masks stats::filter()
## ā dplyr::lag() masks stats::lag()
## ā¹ Use the conflicted package (<http://conflicted.r-lib.org/>) to force all conflicts to become errors
library(rstatix)
## Warning: package 'rstatix' was built under R version 4.4.1
##
## Attaching package: 'rstatix'
##
## The following object is masked from 'package:stats':
##
## filter
library(ggpubr)
## Warning: package 'ggpubr' was built under R version 4.4.1
Loading the data⦠Make sure to set your directory beforehand as needed.
Barrow_Capped_Uncapped <- read.csv("CAPPED_AND_UNCAPPED_BARROW_1_MG_KG.csv")
print(Barrow_Capped_Uncapped)
## Technique pH SiO2 Al2O3 Fe2O3 CaO MgO Na2O
## 1 Uncapped 9.921 143502.52 47579.61 8393.106 255144.60 18513.202 4302.770
## 2 Capped 8.850 221096.72 53189.66 27907.078 95053.87 8201.288 5415.555
## 3 Capped 7.701 215954.93 88649.43 53506.051 34876.91 7960.074 8308.797
## 4 Capped 8.295 260828.69 43292.68 22381.616 79688.02 6633.395 5934.855
## 5 Uncapped 8.363 188376.27 63774.67 25389.146 147226.30 7115.824 2893.242
## 6 Capped 8.047 284200.43 51760.68 31474.148 30874.64 9045.538 6602.526
## 7 Capped 9.841 265970.47 52342.86 29515.756 57389.67 9769.182 6528.341
## 8 Capped 10.294 246805.64 53983.53 25319.203 85762.89 8683.717 5341.370
## 9 Uncapped 10.797 92552.11 25774.49 4406.381 316608.01 6573.091 1409.528
## 10 Capped 9.019 251947.42 44404.10 27067.767 87549.62 10854.646 5712.298
## 11 Uncapped 10.774 129479.47 37735.55 7274.025 278729.40 11216.468 1706.271
## K2O Cr2O3 TiO2 MnO P2O5 SrO BaO LOI
## 1 3569.635 20.52607 2936.7802 4491.853 599.92253 676.47564 3045.2147 16.55
## 2 15772.808 95.78834 3536.1231 1239.132 1399.81923 169.11891 626.9560 19.60
## 3 23161.123 191.57668 8031.1948 2710.601 3699.52226 84.55946 447.8257 15.80
## 4 14444.571 75.26227 3056.6488 619.566 1399.81923 84.55946 447.8257 15.80
## 5 8218.463 75.26227 2876.8459 2942.938 1499.80632 253.67837 3224.3449 18.60
## 6 16602.956 102.63036 3056.6488 1239.132 1599.79341 84.55946 806.0862 14.80
## 7 16353.911 102.63036 3056.6488 1239.132 1299.83214 84.55946 1343.4771 13.80
## 8 14444.571 82.10429 2936.7802 1394.023 1099.85797 84.55946 985.2165 15.90
## 9 2739.488 20.52607 719.2115 1626.361 199.97418 253.67837 2955.6495 27.20
## 10 12286.187 82.10429 2936.7802 2633.155 1099.85797 253.67837 2059.9981 14.95
## 11 3071.547 13.68405 958.9486 1936.144 99.98709 253.67837 5194.7779 19.70
## Ag As B Be Bi Cd Co Cu Ga Hg La Li Mo Ni Pb S Sb Sc Th Tl U
## 1 0.2 5 30 10.3 1.5 0.25 2 28 5 0.5 40 70 0.5 6 11 7000 1.5 15 10 5 5
## 2 0.2 15 20 2.1 1.5 0.25 11 44 5 0.5 20 30 1.0 29 61 1600 3.0 5 10 5 5
## 3 0.2 60 10 1.1 1.5 0.25 31 97 5 0.5 20 40 1.0 60 14 500 5.0 15 10 5 5
## 4 0.2 11 10 0.7 1.5 0.25 9 37 5 0.5 10 20 1.0 23 43 600 1.5 3 10 5 5
## 5 0.5 8 20 5.8 1.5 1.00 4 32 5 0.5 20 40 1.0 10 158 2400 5.0 5 10 5 5
## 6 0.7 12 10 1.5 1.5 1.80 9 41 5 1.0 10 20 1.0 24 240 900 5.0 3 10 5 5
## 7 0.4 10 20 2.5 1.5 0.90 7 39 5 1.0 20 30 1.0 24 124 2300 3.0 4 10 5 5
## 8 0.4 15 20 3.1 1.5 0.80 7 32 5 0.5 20 30 1.0 20 118 2400 5.0 5 10 5 5
## 9 0.3 5 50 6.3 1.5 0.25 1 19 5 0.5 30 40 0.5 4 27 5800 1.5 7 10 5 5
## 10 0.8 12 20 4.5 1.5 1.50 6 42 5 2.0 20 40 1.0 18 211 3300 6.0 5 10 5 5
## 11 0.3 4 60 9.1 1.5 0.25 2 23 5 0.5 30 60 0.5 4 28 11800 1.5 10 10 5 5
## V W Zn Albite Aluminium.oxide.hydroxide Aragonite Calcite Clinochlore
## 1 18 5 24 0 0 0 1 0
## 2 25 5 88 0 0 0 1 0
## 3 39 5 57 1 0 0 1 1
## 4 21 5 68 0 1 0 1 0
## 5 11 5 210 0 0 0 1 0
## 6 23 5 544 0 0 0 0 0
## 7 26 5 215 0 0 0 0 0
## 8 20 5 202 0 0 0 1 0
## 9 7 5 46 0 0 0 1 0
## 10 23 5 399 0 0 1 0 0
## 11 5 5 51 0 0 0 1 0
## Diaspore Gehlenite Illite Kaolinite Melilite Microcline Mullite Muscovite
## 1 0 1 0 0 1 0 0 0
## 2 0 0 0 1 0 0 0 10
## 3 0 0 1 0 0 0 0 1
## 4 0 0 0 1 0 0 0 1
## 5 1 1 0 1 0 0 1 0
## 6 0 0 0 1 0 0 0 1
## 7 0 0 0 1 0 1 0 1
## 8 0 0 0 0 0 0 0 0
## 9 0 0 0 0 0 0 0 0
## 10 0 0 0 0 0 0 0 0
## 11 0 1 0 0 1 0 0 1
## Periclase Phengite Quartz
## 1 0 0 0
## 2 0 0 1
## 3 0 0 1
## 4 1 0 1
## 5 0 0 1
## 6 0 0 1
## 7 0 0 1
## 8 0 1 1
## 9 0 0 1
## 10 0 0 1
## 11 0 0 0
Barrow_Capped_Uncapped_na <- na.omit(Barrow_Capped_Uncapped)
#Before carrying out tests, it is useful to look at histograms of the data to establish #normality. Normally distributed data can be tested using the two-sample t-test, while #data that are not normally distributed ought to undergo Wilcoxon rank sum tests instead.
hist(Barrow_Capped_Uncapped_na$SiO2)
#From this histogram, it can be seen that SiO2 has a non-normal distribution. Therefore, #a Wilcoxon test, rather than a t test, will be carried out for SiO2 in the uncapped and #capped substrates.
SiO2Wilcox <- wilcox.test(Barrow_Capped_Uncapped_na[,3] ~ Barrow_Capped_Uncapped_na[,1])
print(SiO2Wilcox)
##
## Wilcoxon rank sum exact test
##
## data: Barrow_Capped_Uncapped_na[, 3] by Barrow_Capped_Uncapped_na[, 1]
## W = 28, p-value = 0.006061
## alternative hypothesis: true location shift is not equal to 0
#A quick t-test for the data just to obtain the means more quickly and efficientlyā¦
Capping_t_test_SiO2 <- t.test(Barrow_Capped_Uncapped_na[,3] ~ Barrow_Capped_Uncapped_na[,1])
print(Capping_t_test_SiO2)
##
## Welch Two Sample t-test
##
## data: Barrow_Capped_Uncapped_na[, 3] by Barrow_Capped_Uncapped_na[, 1]
## t = 5.0875, df = 4.3318, p-value = 0.00568
## alternative hypothesis: true difference in means between group Capped and group Uncapped is not equal to 0
## 95 percent confidence interval:
## 52240.25 169891.51
## sample estimates:
## mean in group Capped mean in group Uncapped
## 249543.5 138477.6
#The Wilcoxon test demonstrates that there are significant differences between SiO2 on #capped and uncapped parts of the slag bank. SiO2 was recorded in significantly higher #levels on capped substrates on-site.
hist(Barrow_Capped_Uncapped_na$pH)
#Non-normal distribution, will do a Wilcoxon rank sum testā¦
pHWilcox <- wilcox.test(Barrow_Capped_Uncapped_na[,2] ~ Barrow_Capped_Uncapped_na[,1])
print(pHWilcox)
##
## Wilcoxon rank sum exact test
##
## data: Barrow_Capped_Uncapped_na[, 2] by Barrow_Capped_Uncapped_na[, 1]
## W = 5, p-value = 0.1091
## alternative hypothesis: true location shift is not equal to 0
#No significant differences
hist(Barrow_Capped_Uncapped_na$Al2O3)
#Will do a Wilcoxon test for Al2O3 as well, non-normal distribution.
Al2O3Wilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,4] ~ Barrow_Capped_Uncapped_na[,1])
print(Al2O3Wilcox)
##
## Wilcoxon rank sum exact test
##
## data: Barrow_Capped_Uncapped_na[, 4] by Barrow_Capped_Uncapped_na[, 1]
## W = 20, p-value = 0.3152
## alternative hypothesis: true location shift is not equal to 0
#No significant differences
hist(Barrow_Capped_Uncapped_na$Fe2O3)
#Will do a Wilcoxon test for Fe2O3, non-normal distribution.
Fe2O3Wilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,5] ~ Barrow_Capped_Uncapped_na[,1])
print(Fe2O3Wilcox)
##
## Wilcoxon rank sum exact test
##
## data: Barrow_Capped_Uncapped_na[, 5] by Barrow_Capped_Uncapped_na[, 1]
## W = 26, p-value = 0.02424
## alternative hypothesis: true location shift is not equal to 0
#A quick t-test for the data just to obtain the means more quickly and efficientlyā¦
Capping_t_test_Fe2O3 <- t.test(Barrow_Capped_Uncapped_na[,5] ~ Barrow_Capped_Uncapped_na[,1])
print(Capping_t_test_Fe2O3)
##
## Welch Two Sample t-test
##
## data: Barrow_Capped_Uncapped_na[, 5] by Barrow_Capped_Uncapped_na[, 1]
## t = 3.1973, df = 6.8602, p-value = 0.01554
## alternative hypothesis: true difference in means between group Capped and group Uncapped is not equal to 0
## 95 percent confidence interval:
## 5059.266 34258.439
## sample estimates:
## mean in group Capped mean in group Uncapped
## 31024.52 11365.66
#The Wilcoxon test demonstrates that there are significant differences between Fe2O3 on #capped and uncapped parts of the slag bank. Fe2O3 was recorded in significantly higher #levels on capped substrates on-site.
hist(Barrow_Capped_Uncapped_na$CaO)
#Again, a non-normal distribution, so time for another Wilcoxon rank sum testā¦
CaOWilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,6] ~ Barrow_Capped_Uncapped_na[,1])
print(CaOWilcox)
##
## Wilcoxon rank sum exact test
##
## data: Barrow_Capped_Uncapped_na[, 6] by Barrow_Capped_Uncapped_na[, 1]
## W = 0, p-value = 0.006061
## alternative hypothesis: true location shift is not equal to 0
#A quick t-test for the data just to obtain the meansā¦
Capping_t_test_CaO <- t.test(Barrow_Capped_Uncapped_na[,6] ~ Barrow_Capped_Uncapped_na[,1])
print(Capping_t_test_CaO)
##
## Welch Two Sample t-test
##
## data: Barrow_Capped_Uncapped_na[, 6] by Barrow_Capped_Uncapped_na[, 1]
## t = -4.8334, df = 3.4561, p-value = 0.0121
## alternative hypothesis: true difference in means between group Capped and group Uncapped is not equal to 0
## 95 percent confidence interval:
## -293548.3 -70678.5
## sample estimates:
## mean in group Capped mean in group Uncapped
## 67313.66 249427.08
#The Wilcoxon test demonstrates that there are significant differences between CaO on #capped and uncapped parts of the slag bank. CaO was recorded in significantly higher #levels on uncapped substrates on-site.
hist(Barrow_Capped_Uncapped_na$MgO)
#Again, a non-normal distribution, so time for another Wilcoxon rank sum testā¦
MgOWilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,7] ~ Barrow_Capped_Uncapped_na[,1])
print(MgOWilcox)
##
## Wilcoxon rank sum exact test
##
## data: Barrow_Capped_Uncapped_na[, 7] by Barrow_Capped_Uncapped_na[, 1]
## W = 13, p-value = 0.9273
## alternative hypothesis: true location shift is not equal to 0
#No significant differences.
hist(Barrow_Capped_Uncapped_na$Na2O)
#This shows more of a normal distribution, so a t-test can be done for this one.
Capping_t_test_Na2O <- t.test(Barrow_Capped_Uncapped_na[,8] ~ Barrow_Capped_Uncapped_na[,1])
print(Capping_t_test_Na2O)
##
## Welch Two Sample t-test
##
## data: Barrow_Capped_Uncapped_na[, 8] by Barrow_Capped_Uncapped_na[, 1]
## t = 4.8207, df = 5.1455, p-value = 0.004445
## alternative hypothesis: true difference in means between group Capped and group Uncapped is not equal to 0
## 95 percent confidence interval:
## 1736.815 5634.063
## sample estimates:
## mean in group Capped mean in group Uncapped
## 6263.392 2577.953
#From the t-test, it can be seen that Na2O is significantly lower in uncapped than #capped substrates on the Barrow slag bank.
hist(Barrow_Capped_Uncapped_na$K2O)
#Another non-normal distribution, so will do another Wilcoxon rank sum test.
K2OWilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,9] ~ Barrow_Capped_Uncapped_na[,1])
## Warning in wilcox.test.default(x = DATA[[1L]], y = DATA[[2L]], ...): cannot
## compute exact p-value with ties
print(K2OWilcox)
##
## Wilcoxon rank sum test with continuity correction
##
## data: Barrow_Capped_Uncapped_na[, 9] by Barrow_Capped_Uncapped_na[, 1]
## W = 28, p-value = 0.01056
## alternative hypothesis: true location shift is not equal to 0
#A quick t-test for the data just to obtain the meansā¦
Capping_t_test_K2O <- t.test(Barrow_Capped_Uncapped_na[,9] ~ Barrow_Capped_Uncapped_na[,1])
print(Capping_t_test_K2O)
##
## Welch Two Sample t-test
##
## data: Barrow_Capped_Uncapped_na[, 9] by Barrow_Capped_Uncapped_na[, 1]
## t = 6.4472, df = 8.0387, p-value = 0.0001948
## alternative hypothesis: true difference in means between group Capped and group Uncapped is not equal to 0
## 95 percent confidence interval:
## 7552.434 15952.608
## sample estimates:
## mean in group Capped mean in group Uncapped
## 16152.304 4399.783
#K2O is present in significantly higher concentrations in uncapped parts of the Barrow slag #bank.
hist(Barrow_Capped_Uncapped_na$Cr2O3)
#Non-normal distribution.
Cr2O3Wilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,10] ~ Barrow_Capped_Uncapped_na[,1])
## Warning in wilcox.test.default(x = DATA[[1L]], y = DATA[[2L]], ...): cannot
## compute exact p-value with ties
print(Cr2O3Wilcox)
##
## Wilcoxon rank sum test with continuity correction
##
## data: Barrow_Capped_Uncapped_na[, 10] by Barrow_Capped_Uncapped_na[, 1]
## W = 27.5, p-value = 0.01316
## alternative hypothesis: true location shift is not equal to 0
#A quick t-test for the data just to obtain the meansā¦
Capping_t_test_Cr2O3 <- t.test(Barrow_Capped_Uncapped_na[,10] ~ Barrow_Capped_Uncapped_na[,1])
print(Capping_t_test_Cr2O3)
##
## Welch Two Sample t-test
##
## data: Barrow_Capped_Uncapped_na[, 10] by Barrow_Capped_Uncapped_na[, 1]
## t = 3.4661, df = 8.247, p-value = 0.008102
## alternative hypothesis: true difference in means between group Capped and group Uncapped is not equal to 0
## 95 percent confidence interval:
## 24.3760 119.7952
## sample estimates:
## mean in group Capped mean in group Uncapped
## 104.58523 32.49962
#Cr2O3 levels are significantly higher in capped substrates on the Barrow slag bank.
hist(Barrow_Capped_Uncapped_na$TiO2)
#Non-normal distribution
TiO2Wilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,11] ~ Barrow_Capped_Uncapped_na[,1])
## Warning in wilcox.test.default(x = DATA[[1L]], y = DATA[[2L]], ...): cannot
## compute exact p-value with ties
print(TiO2Wilcox)
##
## Wilcoxon rank sum test with continuity correction
##
## data: Barrow_Capped_Uncapped_na[, 11] by Barrow_Capped_Uncapped_na[, 1]
## W = 27, p-value = 0.01611
## alternative hypothesis: true location shift is not equal to 0
#T-test for meansā¦
Capping_t_test_TiO2 <- t.test(Barrow_Capped_Uncapped_na[,11] ~ Barrow_Capped_Uncapped_na[,1])
print(Capping_t_test_TiO2)
##
## Welch Two Sample t-test
##
## data: Barrow_Capped_Uncapped_na[, 11] by Barrow_Capped_Uncapped_na[, 1]
## t = 2.0776, df = 8.7288, p-value = 0.06848
## alternative hypothesis: true difference in means between group Capped and group Uncapped is not equal to 0
## 95 percent confidence interval:
## -181.3105 4038.5102
## sample estimates:
## mean in group Capped mean in group Uncapped
## 3801.546 1872.947
#TiO2 levels are significantly higher in capped substrates on the Barrow slag bank.
hist(Barrow_Capped_Uncapped_na$MnO)
#Non-normal distribution
MnOWilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,12] ~ Barrow_Capped_Uncapped_na[,1])
## Warning in wilcox.test.default(x = DATA[[1L]], y = DATA[[2L]], ...): cannot
## compute exact p-value with ties
print(MnOWilcox)
##
## Wilcoxon rank sum test with continuity correction
##
## data: Barrow_Capped_Uncapped_na[, 12] by Barrow_Capped_Uncapped_na[, 1]
## W = 4, p-value = 0.07
## alternative hypothesis: true location shift is not equal to 0
#No significant differences.
hist(Barrow_Capped_Uncapped_na$P2O5)
#Non-normal distribution
P2O5Wilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,13] ~ Barrow_Capped_Uncapped_na[,1])
## Warning in wilcox.test.default(x = DATA[[1L]], y = DATA[[2L]], ...): cannot
## compute exact p-value with ties
print(P2O5Wilcox)
##
## Wilcoxon rank sum test with continuity correction
##
## data: Barrow_Capped_Uncapped_na[, 13] by Barrow_Capped_Uncapped_na[, 1]
## W = 23, p-value = 0.1066
## alternative hypothesis: true location shift is not equal to 0
#No significant differences
hist(Barrow_Capped_Uncapped_na$SrO)
#Non-normal distribution
SrOWilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,14] ~ Barrow_Capped_Uncapped_na[,1])
## Warning in wilcox.test.default(x = DATA[[1L]], y = DATA[[2L]], ...): cannot
## compute exact p-value with ties
print(SrOWilcox)
##
## Wilcoxon rank sum test with continuity correction
##
## data: Barrow_Capped_Uncapped_na[, 14] by Barrow_Capped_Uncapped_na[, 1]
## W = 1.5, p-value = 0.01468
## alternative hypothesis: true location shift is not equal to 0
#T-test for meansā¦
Capping_t_test_SrO <- t.test(Barrow_Capped_Uncapped_na[,14] ~ Barrow_Capped_Uncapped_na[,1])
print(Capping_t_test_SrO)
##
## Welch Two Sample t-test
##
## data: Barrow_Capped_Uncapped_na[, 14] by Barrow_Capped_Uncapped_na[, 1]
## t = -2.1959, df = 3.3438, p-value = 0.1064
## alternative hypothesis: true difference in means between group Capped and group Uncapped is not equal to 0
## 95 percent confidence interval:
## -565.07969 87.92277
## sample estimates:
## mean in group Capped mean in group Uncapped
## 120.7992 359.3777
#SrO levels are significantly higher in uncapped substrates on the Barrow slag bank.
hist(Barrow_Capped_Uncapped_na$BaO)
#Non-normal distribution
BaOWilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,15] ~ Barrow_Capped_Uncapped_na[,1])
## Warning in wilcox.test.default(x = DATA[[1L]], y = DATA[[2L]], ...): cannot
## compute exact p-value with ties
print(BaOWilcox)
##
## Wilcoxon rank sum test with continuity correction
##
## data: Barrow_Capped_Uncapped_na[, 15] by Barrow_Capped_Uncapped_na[, 1]
## W = 0, p-value = 0.01056
## alternative hypothesis: true location shift is not equal to 0
#T-test for meansā¦
Capping_t_test_BaO <- t.test(Barrow_Capped_Uncapped_na[,15] ~ Barrow_Capped_Uncapped_na[,1])
print(Capping_t_test_BaO)
##
## Welch Two Sample t-test
##
## data: Barrow_Capped_Uncapped_na[, 15] by Barrow_Capped_Uncapped_na[, 1]
## t = -4.5914, df = 4.0428, p-value = 0.009846
## alternative hypothesis: true difference in means between group Capped and group Uncapped is not equal to 0
## 95 percent confidence interval:
## -4238.407 -1052.333
## sample estimates:
## mean in group Capped mean in group Uncapped
## 959.6265 3604.9968
#BaO levels are significantly higher in uncapped parts of the Barrow slag bank.
hist(Barrow_Capped_Uncapped$LOI)
#Non-normal distribution
LOIWilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,16] ~ Barrow_Capped_Uncapped_na[,1])
## Warning in wilcox.test.default(x = DATA[[1L]], y = DATA[[2L]], ...): cannot
## compute exact p-value with ties
print(LOIWilcox)
##
## Wilcoxon rank sum test with continuity correction
##
## data: Barrow_Capped_Uncapped_na[, 16] by Barrow_Capped_Uncapped_na[, 1]
## W = 2, p-value = 0.02939
## alternative hypothesis: true location shift is not equal to 0
#T-test for meansā¦
Capping_t_test_LOI <- t.test(Barrow_Capped_Uncapped_na[,16] ~ Barrow_Capped_Uncapped_na[,1])
print(Capping_t_test_LOI)
##
## Welch Two Sample t-test
##
## data: Barrow_Capped_Uncapped_na[, 16] by Barrow_Capped_Uncapped_na[, 1]
## t = -1.9412, df = 3.5439, p-value = 0.1333
## alternative hypothesis: true difference in means between group Capped and group Uncapped is not equal to 0
## 95 percent confidence interval:
## -11.791047 2.380333
## sample estimates:
## mean in group Capped mean in group Uncapped
## 15.80714 20.51250
#LOI is significantly higher in uncapped parts of the Barrow slag bank.
hist(Barrow_Capped_Uncapped_na$Ag)
#Non-normal distribution
AgWilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,17] ~ Barrow_Capped_Uncapped_na[,1])
## Warning in wilcox.test.default(x = DATA[[1L]], y = DATA[[2L]], ...): cannot
## compute exact p-value with ties
print(AgWilcox)
##
## Wilcoxon rank sum test with continuity correction
##
## data: Barrow_Capped_Uncapped_na[, 17] by Barrow_Capped_Uncapped_na[, 1]
## W = 15.5, p-value = 0.8459
## alternative hypothesis: true location shift is not equal to 0
#No significant differences
hist(Barrow_Capped_Uncapped_na$As)
#Non-normal distribution
AsWilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,18] ~ Barrow_Capped_Uncapped_na[,1])
## Warning in wilcox.test.default(x = DATA[[1L]], y = DATA[[2L]], ...): cannot
## compute exact p-value with ties
print(AsWilcox)
##
## Wilcoxon rank sum test with continuity correction
##
## data: Barrow_Capped_Uncapped_na[, 18] by Barrow_Capped_Uncapped_na[, 1]
## W = 28, p-value = 0.0102
## alternative hypothesis: true location shift is not equal to 0
#T-test for means.
Capping_t_test_As <- t.test(Barrow_Capped_Uncapped_na[,18] ~ Barrow_Capped_Uncapped_na[,1])
print(Capping_t_test_As)
##
## Welch Two Sample t-test
##
## data: Barrow_Capped_Uncapped_na[, 18] by Barrow_Capped_Uncapped_na[, 1]
## t = 2.0043, df = 6.1917, p-value = 0.0904
## alternative hypothesis: true difference in means between group Capped and group Uncapped is not equal to 0
## 95 percent confidence interval:
## -2.918837 30.490266
## sample estimates:
## mean in group Capped mean in group Uncapped
## 19.28571 5.50000
#Significantly higher levels of As on capped substrates on the Barrow slag bank.
hist(Barrow_Capped_Uncapped_na$B)
#Non-normal distribution.
BWilcoxB <-wilcox.test(Barrow_Capped_Uncapped_na[,19] ~ Barrow_Capped_Uncapped_na[,1])
## Warning in wilcox.test.default(x = DATA[[1L]], y = DATA[[2L]], ...): cannot
## compute exact p-value with ties
print(BWilcoxB)
##
## Wilcoxon rank sum test with continuity correction
##
## data: Barrow_Capped_Uncapped_na[, 19] by Barrow_Capped_Uncapped_na[, 1]
## W = 2, p-value = 0.02131
## alternative hypothesis: true location shift is not equal to 0
#T-test for meansā¦
Capping_t_test_B <- t.test(Barrow_Capped_Uncapped_na[,19] ~ Barrow_Capped_Uncapped_na[,1])
print(Capping_t_test_B)
##
## Welch Two Sample t-test
##
## data: Barrow_Capped_Uncapped_na[, 19] by Barrow_Capped_Uncapped_na[, 1]
## t = -2.5975, df = 3.2971, p-value = 0.07315
## alternative hypothesis: true difference in means between group Capped and group Uncapped is not equal to 0
## 95 percent confidence interval:
## -52.579461 4.008032
## sample estimates:
## mean in group Capped mean in group Uncapped
## 15.71429 40.00000
#B conc is significantly higher in the uncapped substrates on the Barrow slag bank.
hist(Barrow_Capped_Uncapped_na$Be)
#Non-normal distribution
BeWilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,20] ~ Barrow_Capped_Uncapped_na[,1])
print(BeWilcox)
##
## Wilcoxon rank sum exact test
##
## data: Barrow_Capped_Uncapped_na[, 20] by Barrow_Capped_Uncapped_na[, 1]
## W = 0, p-value = 0.006061
## alternative hypothesis: true location shift is not equal to 0
#T-test for means
Capping_t_test_Be <- t.test(Barrow_Capped_Uncapped_na[,20] ~ Barrow_Capped_Uncapped_na[,1])
print(Capping_t_test_Be)
##
## Welch Two Sample t-test
##
## data: Barrow_Capped_Uncapped_na[, 20] by Barrow_Capped_Uncapped_na[, 1]
## t = -4.7466, df = 4.2643, p-value = 0.007675
## alternative hypothesis: true difference in means between group Capped and group Uncapped is not equal to 0
## 95 percent confidence interval:
## -8.892461 -2.428967
## sample estimates:
## mean in group Capped mean in group Uncapped
## 2.214286 7.875000
#Be levels are significantly higher in uncapped substrates on the Barrow slag bank.
#Skipping Bi because recorded values are the same in each sample.
hist(Barrow_Capped_Uncapped_na$Cd)
#Non-normal distribution
CdWilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,22] ~ Barrow_Capped_Uncapped_na[,1])
## Warning in wilcox.test.default(x = DATA[[1L]], y = DATA[[2L]], ...): cannot
## compute exact p-value with ties
print(CdWilcox)
##
## Wilcoxon rank sum test with continuity correction
##
## data: Barrow_Capped_Uncapped_na[, 22] by Barrow_Capped_Uncapped_na[, 1]
## W = 18.5, p-value = 0.4097
## alternative hypothesis: true location shift is not equal to 0
#No significant differences
hist(Barrow_Capped_Uncapped_na$Co)
#Non-normal distribution
CoWilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,23] ~ Barrow_Capped_Uncapped_na[,1])
## Warning in wilcox.test.default(x = DATA[[1L]], y = DATA[[2L]], ...): cannot
## compute exact p-value with ties
print(CoWilcox)
##
## Wilcoxon rank sum test with continuity correction
##
## data: Barrow_Capped_Uncapped_na[, 23] by Barrow_Capped_Uncapped_na[, 1]
## W = 28, p-value = 0.0102
## alternative hypothesis: true location shift is not equal to 0
#T-test for means.
Capping_t_test_Co <- t.test(Barrow_Capped_Uncapped_na[,23] ~ Barrow_Capped_Uncapped_na[,1])
print(Capping_t_test_Co)
##
## Welch Two Sample t-test
##
## data: Barrow_Capped_Uncapped_na[, 23] by Barrow_Capped_Uncapped_na[, 1]
## t = 2.7141, df = 6.4214, p-value = 0.03264
## alternative hypothesis: true difference in means between group Capped and group Uncapped is not equal to 0
## 95 percent confidence interval:
## 1.033453 17.323690
## sample estimates:
## mean in group Capped mean in group Uncapped
## 11.42857 2.25000
#Co levels are significantly higher in capped substrates on the Barrow slag bank.
hist(Barrow_Capped_Uncapped_na$Cu)
#Non-normal distribution
CuWilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,24] ~ Barrow_Capped_Uncapped_na[,1])
## Warning in wilcox.test.default(x = DATA[[1L]], y = DATA[[2L]], ...): cannot
## compute exact p-value with ties
print(CuWilcox)
##
## Wilcoxon rank sum test with continuity correction
##
## data: Barrow_Capped_Uncapped_na[, 24] by Barrow_Capped_Uncapped_na[, 1]
## W = 27.5, p-value = 0.0138
## alternative hypothesis: true location shift is not equal to 0
#T test for meansā¦
Capping_t_test_Cu <- t.test(Barrow_Capped_Uncapped_na[,24] ~ Barrow_Capped_Uncapped_na[,1])
print(Capping_t_test_Cu)
##
## Welch Two Sample t-test
##
## data: Barrow_Capped_Uncapped_na[, 24] by Barrow_Capped_Uncapped_na[, 1]
## t = 2.4749, df = 7.265, p-value = 0.04132
## alternative hypothesis: true difference in means between group Capped and group Uncapped is not equal to 0
## 95 percent confidence interval:
## 1.131213 42.725930
## sample estimates:
## mean in group Capped mean in group Uncapped
## 47.42857 25.50000
#Cu is significantly higher in capped substrates on the Barrow slag bank.
#Skipping Ga because recorded values are the same in each sample.
hist(Barrow_Capped_Uncapped_na$Hg)
#Non-normal distribution
HgWilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,26] ~ Barrow_Capped_Uncapped_na[,1])
## Warning in wilcox.test.default(x = DATA[[1L]], y = DATA[[2L]], ...): cannot
## compute exact p-value with ties
print(HgWilcox)
##
## Wilcoxon rank sum test with continuity correction
##
## data: Barrow_Capped_Uncapped_na[, 26] by Barrow_Capped_Uncapped_na[, 1]
## W = 20, p-value = 0.1846
## alternative hypothesis: true location shift is not equal to 0
#No significant differences.
hist(Barrow_Capped_Uncapped_na$La)
#Non-normal distribution
LaWilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,27] ~ Barrow_Capped_Uncapped_na[,1])
## Warning in wilcox.test.default(x = DATA[[1L]], y = DATA[[2L]], ...): cannot
## compute exact p-value with ties
print(LaWilcox)
##
## Wilcoxon rank sum test with continuity correction
##
## data: Barrow_Capped_Uncapped_na[, 27] by Barrow_Capped_Uncapped_na[, 1]
## W = 2.5, p-value = 0.02265
## alternative hypothesis: true location shift is not equal to 0
#Will do a t-test for means.
Capping_t_test_La <- t.test(Barrow_Capped_Uncapped_na[,27] ~ Barrow_Capped_Uncapped_na[,1])
print(Capping_t_test_La)
##
## Welch Two Sample t-test
##
## data: Barrow_Capped_Uncapped_na[, 27] by Barrow_Capped_Uncapped_na[, 1]
## t = -2.8701, df = 4.2607, p-value = 0.04219
## alternative hypothesis: true difference in means between group Capped and group Uncapped is not equal to 0
## 95 percent confidence interval:
## -25.0004094 -0.7138763
## sample estimates:
## mean in group Capped mean in group Uncapped
## 17.14286 30.00000
#La levels are significantly higher in uncapped substrates on the Barrow slag bank.
hist(Barrow_Capped_Uncapped_na$Li)
#Non-normal distribution
LiWilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,28] ~ Barrow_Capped_Uncapped_na[,1])
## Warning in wilcox.test.default(x = DATA[[1L]], y = DATA[[2L]], ...): cannot
## compute exact p-value with ties
print(LiWilcox)
##
## Wilcoxon rank sum test with continuity correction
##
## data: Barrow_Capped_Uncapped_na[, 28] by Barrow_Capped_Uncapped_na[, 1]
## W = 2, p-value = 0.02436
## alternative hypothesis: true location shift is not equal to 0
#T-test for meansā¦
Capping_t_test_Li <- t.test(Barrow_Capped_Uncapped_na[,28] ~ Barrow_Capped_Uncapped_na[,1])
print(Capping_t_test_Li)
##
## Welch Two Sample t-test
##
## data: Barrow_Capped_Uncapped_na[, 28] by Barrow_Capped_Uncapped_na[, 1]
## t = -2.7743, df = 4.0439, p-value = 0.0495
## alternative hypothesis: true difference in means between group Capped and group Uncapped is not equal to 0
## 95 percent confidence interval:
## -44.92116324 -0.07883676
## sample estimates:
## mean in group Capped mean in group Uncapped
## 30.0 52.5
#Li levels are significantly higher on uncapped parts of the Barrow slag bank.
#Skipping Mo because of similarities of values.
hist(Barrow_Capped_Uncapped_na$Ni)
#Non-normal distribution
NiWilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,30] ~ Barrow_Capped_Uncapped_na[,1])
## Warning in wilcox.test.default(x = DATA[[1L]], y = DATA[[2L]], ...): cannot
## compute exact p-value with ties
print(NiWilcox)
##
## Wilcoxon rank sum test with continuity correction
##
## data: Barrow_Capped_Uncapped_na[, 30] by Barrow_Capped_Uncapped_na[, 1]
## W = 28, p-value = 0.01038
## alternative hypothesis: true location shift is not equal to 0
#T test for meansā¦
Capping_t_test_Ni <- t.test(Barrow_Capped_Uncapped_na[,30] ~ Barrow_Capped_Uncapped_na[,1])
print(Capping_t_test_Ni)
##
## Welch Two Sample t-test
##
## data: Barrow_Capped_Uncapped_na[, 30] by Barrow_Capped_Uncapped_na[, 1]
## t = 3.9611, df = 6.775, p-value = 0.005825
## alternative hypothesis: true difference in means between group Capped and group Uncapped is not equal to 0
## 95 percent confidence interval:
## 8.892005 35.679424
## sample estimates:
## mean in group Capped mean in group Uncapped
## 28.28571 6.00000
#Ni levels are significantly higher in capped substrates on the Barrow slag bank.
hist(Barrow_Capped_Uncapped_na$Pb)
#Non-normal distribution.
PbWilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,31] ~ Barrow_Capped_Uncapped_na[,1])
print(PbWilcox)
##
## Wilcoxon rank sum exact test
##
## data: Barrow_Capped_Uncapped_na[, 31] by Barrow_Capped_Uncapped_na[, 1]
## W = 21, p-value = 0.2303
## alternative hypothesis: true location shift is not equal to 0
#No significant differences
hist(Barrow_Capped_Uncapped_na$S)
#Non-normal distribution
SWilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,32] ~ Barrow_Capped_Uncapped_na[,1])
## Warning in wilcox.test.default(x = DATA[[1L]], y = DATA[[2L]], ...): cannot
## compute exact p-value with ties
print(SWilcox)
##
## Wilcoxon rank sum test with continuity correction
##
## data: Barrow_Capped_Uncapped_na[, 32] by Barrow_Capped_Uncapped_na[, 1]
## W = 1.5, p-value = 0.02303
## alternative hypothesis: true location shift is not equal to 0
#T test for meansā¦
Capping_t_test_S <- t.test(Barrow_Capped_Uncapped_na[,32] ~ Barrow_Capped_Uncapped_na[,1])
print(Capping_t_test_S)
##
## Welch Two Sample t-test
##
## data: Barrow_Capped_Uncapped_na[, 32] by Barrow_Capped_Uncapped_na[, 1]
## t = -2.5651, df = 3.2554, p-value = 0.07635
## alternative hypothesis: true difference in means between group Capped and group Uncapped is not equal to 0
## 95 percent confidence interval:
## -11140.0362 954.3219
## sample estimates:
## mean in group Capped mean in group Uncapped
## 1657.143 6750.000
#S levels are significantly higher on the uncapped parts of the Barrow slag bank.
hist(Barrow_Capped_Uncapped_na$Sb)
#Non-normal distribution
SbWilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,33] ~ Barrow_Capped_Uncapped_na[,1])
## Warning in wilcox.test.default(x = DATA[[1L]], y = DATA[[2L]], ...): cannot
## compute exact p-value with ties
print(SbWilcox)
##
## Wilcoxon rank sum test with continuity correction
##
## data: Barrow_Capped_Uncapped_na[, 33] by Barrow_Capped_Uncapped_na[, 1]
## W = 22, p-value = 0.1362
## alternative hypothesis: true location shift is not equal to 0
#No significant differences
hist(Barrow_Capped_Uncapped_na$Sc)
#Non-normal distribution
ScWilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,34] ~ Barrow_Capped_Uncapped_na[,1])
## Warning in wilcox.test.default(x = DATA[[1L]], y = DATA[[2L]], ...): cannot
## compute exact p-value with ties
print(ScWilcox)
##
## Wilcoxon rank sum test with continuity correction
##
## data: Barrow_Capped_Uncapped_na[, 34] by Barrow_Capped_Uncapped_na[, 1]
## W = 5, p-value = 0.09853
## alternative hypothesis: true location shift is not equal to 0
#No significant differences
#Skipping Th, Tl and U because of similar concentrations between samples.
hist(Barrow_Capped_Uncapped_na$V)
#Close to a normal distribution, will do a t test for this oneā¦
Capping_t_test_V <- t.test(Barrow_Capped_Uncapped_na[,38] ~ Barrow_Capped_Uncapped_na[,1])
print(Capping_t_test_V)
##
## Welch Two Sample t-test
##
## data: Barrow_Capped_Uncapped_na[, 38] by Barrow_Capped_Uncapped_na[, 1]
## t = 4.0081, df = 7.0068, p-value = 0.005127
## alternative hypothesis: true difference in means between group Capped and group Uncapped is not equal to 0
## 95 percent confidence interval:
## 6.166895 23.904533
## sample estimates:
## mean in group Capped mean in group Uncapped
## 25.28571 10.25000
#V levels are significantly higher in capped parts of the Barrow slag bank.
#Skipping W as all samples had the same concentration.
hist(Barrow_Capped_Uncapped_na$Zn)
#Non-normal distribution
ZnWilcox <-wilcox.test(Barrow_Capped_Uncapped_na[,40] ~ Barrow_Capped_Uncapped_na[,1])
print(ZnWilcox)
##
## Wilcoxon rank sum exact test
##
## data: Barrow_Capped_Uncapped_na[, 40] by Barrow_Capped_Uncapped_na[, 1]
## W = 24, p-value = 0.07273
## alternative hypothesis: true location shift is not equal to 0
#No significant differences.