So these are the survey results. I have tried to do pairwise testing (pairwise.wilcox.test) for these results collected in Spring and Autumn for these sites. But I can't get a specific P -value as to which site has the most influence.
This is the error message I keep getting. My dataset isn't even, ie there were some of the sites that were not surveyed in Spring which I think may be the issue.
Error in wilcox.test.default(xi, xj, paired = paired, ...) : 'x' must be numeric
So I'm not sure if I have laid it out in the table wrong to see how much site influences the results between Spring and Autumn
Site Autumn Spring
Stokes Bay 25 6
Stokes Bay 54 6
Stokes Bay 31 0
Gosport Wall 213 16
Gosport Wall 24 19
Gosport Wall 54 60
No Mans Land 76 25
No Mans Land 66 68
No Mans Land 229 103
Osbourne 1 77
Osbourne 1 92
Osbourne 1 92
Osbourne 2 114 33
Osbourne 2 217 114
Osbourne 2 117 64
Osbourne 3 204 131
Osbourne 3 165 85
Osbourne 3 150 81
Osbourne 4 124 15
Osbourne 4 79 64
Osbourne 4 176 65
Ryde Roads 217 165
Ryde Roads 182 63
Ryde Roads 112 53
Ryde Sands 386 44
Ryde Sands 375 25
Ryde Sands 147 45
Spit Bank 223 23
Spit Bank 78 29
Spit Bank 60 15
St Helen's 1 247 11
St Helen's 1 126 36
St Helen's 1 107 20
St Helen's 2 108 115
St Helen's 2 223 25
St Helen's 2 126 30
Sturbridge 58 43
Sturbridge 107 34
Sturbridge 156 0
Osbourne Deep 1 76 59
Osbourne Deep 1 64 52
Osbourne Deep 1 77 30
Osbourne Deep 2 153 60
Osbourne Deep 2 106 88
Osbourne Deep 2 74 35
Sturbridge Shoal 169 45
Sturbridge Shoal 19 84
Sturbridge Shoal 81 44
Mother's Bank 208
Mother's Bank 119
Mother's Bank 153
Ryde Middle 16
Ryde Middle 36
Ryde Middle 36
Stanswood 14 132
Stanswood 47 87
Stanswood 14 88
This is what I've done so far:
MWU <- read.csv(file.choose(), header = T)
#attach file to workspace
attach(MWU)
#Read column names of the data
colnames(MWU) # Site, Autumn, Spring
MWU.1 <- MWU[c(1,2,3)] #It included blank columns in the df
kruskal.test(MWU.1$Autumn ~ MWU.1$Site)
#Kruskal-Wallis rank sum test
#data: MWU.1$Autumn by MWU.1$Site
#Kruskal-Wallis chi-squared = 36.706, df = 24, p-value = 0.0468
kruskal.test(MWU.1$Spring ~ MWU.1$Site)
#Kruskal-Wallis rank sum test
#data: MWU.1$Spring by MWU.1$Site
#Kruskal-Wallis chi-squared = 35.134, df = 21, p-value = 0.02729
wilcox.test(MWU.1$Autumn, MWU.1$Spring, paired = T)
#Wilcoxon signed rank exact test
#data: MWU.1$Autumn and MWU.1$Spring**
#V = 1066, p-value = 8.127e-08**
#alternative hypothesis: true location shift is not equal to 0******
#Tried this version too to see if it would give a summary of where the influence is.
pairwise.wilcox.test(MWU.1$Spring, MWU.1$Autumn)
#Error in wilcox.test.default(xi, xj, paired = paired, ...) : not enough (non-missing) 'x' observations