Place the default kernel code in the textbox

gp_visualizer.py

@@ -80,16 +80,13 @@ def make_sine(xlim=(0,1), nsample=20, sigma=0.1, uniform=False, sort=True):
     return X, y
 
 class GPVisualizer:
+    DEFAULT_KERNEL = "RBF() + WhiteKernel()"
+
     def __init__(self, width, height):
         self.canvas_width = width
         self.canvas_height = height
 
-        #self.kernels = {
-            #"RBF": RBF(),
-            #"Matern": Matern(),
-        #}
-        #self.kernel = self.kernels["RBF"]
-        self.kernel = RBF() + WhiteKernel()
+        self.kernel = eval_kernel(self.DEFAULT_KERNEL)
 
         self.css = """
 .hidden-button {
@@ -215,16 +212,13 @@ class GPVisualizer:
                         file_chooser = gr.File(label="Choose a file", visible=False, elem_id="rowheight")
                         self.file_chooser = file_chooser
 
-                        # kernel type 
-                        #kernel_type = gr.Dropdown(choices=['RBF', 'Matern'],
-                                                #label='Kernel',
-                                                #value='RBF',
-                                                #visible=True)
-
                         # kernel spec
-                        kernel_spec = gr.Textbox(label="Kernel",
-                                                 placeholder='sklearn kernel code, default "RBF() + WhiteKernel()"',
-                                                 interactive=True)
+                        kernel_spec = gr.Textbox(
+                            label="Kernel",
+                            placeholder="sklearn kernel code",
+                            value=self.DEFAULT_KERNEL,
+                            interactive=True,
+                        )
 
                         #gr.Markdown(''.join(open('kernel_examples.md', 'r').readlines()))