Lab 3: Fixed error for rbf kernel in assignment 3

lab3/assignment3.R

@@ -89,8 +89,8 @@ err3
 
 # 3. Implementation of SVM predictions.
 
-gaussian_kernel <- function(x, sigma = 0.05) {
-  exp(-(x ^ 2) / (2 * sigma ^ 2))
+rbf_kernel <- function(x1, x2, lambda = 0.05) {
+  exp(-(dist(rbind(x1,x2)) ^ 2) * lambda)
 }
 
 sv <- alphaindex(filter3)[[1]]
@@ -103,7 +103,7 @@ for (i in 1:10) {
   data_point <- spam[i, -58]
   for (j in 1:length(sv)) {
     support_vector <- spam[sv[j], -58]
-    kernel_value <- gaussian_kernel(sum((support_vector - data_point)^2), sigma = 0.05)
+    kernel_value <- rbf_kernel(support_vector, data_point)
     k2 <- k2 + co[j] * kernel_value
   }
   print(k2)