When to use it
Null hypothesis
Assumption
How the test works
See the Handbook for information on these topics.
Example
Example of Spearman rank correlation
###
--------------------------------------------------------------
### Spearman rank correlation, frigatebird example
### p. 212
### --------------------------------------------------------------
Input = ("
Volume Pitch
1760 529
2040 566
2440 473
2550 461
2730 465
2740 532
3010 484
3080 527
3370 488
3740 485
4910 478
5090 434
5090 468
5380 449
5850 425
6730 389
6990 421
7960 416
")
Data = read.table(textConnection(Input),header=TRUE)
cor.test( ~ Pitch + Volume,
data=Data,
method = "spearman",
continuity = FALSE,
conf.level = 0.95)
Spearman's rank correlation rho
S = 1708.382, p-value = 0.0002302
sample estimates:
rho
-0.7630357
Simple plot of the data
plot(Pitch ~ Volume,
data=Data,
pch=16)
# # #
Graphing the results
See the Handbook for information on this topic.
How to do the test
Example of Spearman rank correlation
###
--------------------------------------------------------------
### Spearman rank correlation, species diversity example
### p. 214
### --------------------------------------------------------------
Input = ("
Town State Latitude Species
'Bombay Hook' DE 39.217 128
'Cape Henlopen' DE 38.800 137
'Middletown' DE 39.467 108
'Milford' DE 38.958 118
'Rehoboth' DE 38.600 135
'Seaford-Nanticoke' DE 38.583 94
'Wilmington' DE 39.733 113
'Crisfield' MD 38.033 118
'Denton' MD 38.900 96
'Elkton' MD 39.533 98
'Lower Kent County' MD 39.133 121
'Ocean City' MD 38.317 152
'Salisbury' MD 38.333 108
'S Dorchester County' MD 38.367 118
'Cape Charles' VA 37.200 157
'Chincoteague' VA 37.967 125
'Wachapreague' VA 37.667 114
")
Data = read.table(textConnection(Input),header=TRUE)
cor.test( ~ Species + Latitude,
data=Data,
method = "spearman",
continuity = FALSE,
conf.level = 0.95)
Spearman's rank correlation rho
S = 1111.908, p-value = 0.1526
rho
-0.3626323
Simple plot of the data
plot(Species ~ Latitude,
data=Data,
pch=16)
# # #