add tests

DESCRIPTION

@@ -1,7 +1,7 @@
 Type: Package
 Package: parameters
 Title: Processing of Model Parameters
-Version: 0.21.7.3
+Version: 0.21.7.4
 Authors@R:
     c(person(given = "Daniel",
              family = "Lüdecke",

tests/testthat/_snaps/pca.md

@@ -0,0 +1,32 @@
+# print model_parameters pca
+
+    Code
+      print(principal_components(mtcars[, 1:4], n = "auto"))
+    Output
+      # Loadings from Principal Component Analysis (no rotation)
+      
+      Variable |   PC1 | Complexity
+      -----------------------------
+      mpg      | -0.93 |       1.00
+      cyl      |  0.96 |       1.00
+      disp     |  0.95 |       1.00
+      hp       |  0.91 |       1.00
+      
+      The unique principal component accounted for 87.55% of the total variance of the original data.
+
+---
+
+    Code
+      print(principal_components(mtcars[, 1:4], n = "auto"), labels = c(
+        "Miles/(US) gallon", "Number of cylinders", "Displacement (cu.in.)",
+        "Gross horsepower"))
+    Output
+      # Loadings from Principal Component Analysis (no rotation)
+      
+      Variable | Label                 |   PC1 | Complexity
+      -----------------------------------------------------
+      mpg      | Miles/(US) gallon     | -0.93 |       1.00
+      cyl      | Number of cylinders   |  0.96 |       1.00
+      disp     | Displacement (cu.in.) |  0.95 |       1.00
+      hp       | Gross horsepower      |  0.91 |       1.00
+

tests/testthat/test-pca.R

@@ -59,6 +59,23 @@ test_that("principal_components", {
 })
 
 
+# print ----
+
+test_that("print model_parameters pca", {
+  data(mtcars)
+  expect_snapshot(print(principal_components(mtcars[, 1:4], n = "auto")))
+  expect_snapshot(print(
+    principal_components(mtcars[, 1:4], n = "auto"),
+    labels = c(
+      "Miles/(US) gallon",
+      "Number of cylinders",
+      "Displacement (cu.in.)",
+      "Gross horsepower"
+    )
+  ))
+})
+
+
 # predict ----------------------
 # N.B tests will fail if `GPArotation` package is not installed